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Kentucky Roof Code · Penetrations

Solar panels on a Kentucky roof are governed by a code section most homeowners never see, and it is short enough to read in one sitting. Rooftop-mounted photovoltaic systems fall under Section R909 of the Kentucky Residential Code, and R909.3 sends every penetration those panels make straight back to the same flashing chapter that governs a chimney, a vent or a skylight. That single cross-reference is the whole answer to “will the array leak.”

What does the Kentucky code actually say about a solar mount penetration?

R909.3 requires rooftop photovoltaic systems to be installed per the manufacturer’s instructions, and requires roof penetrations to be flashed and sealed in accordance with the roof assemblies chapter.

Section R909.1 provides that the installation of photovoltaic panel systems mounted on or above the roof covering shall comply with that section, Section R324 and NFPA 70. R909.2 requires the system to be designed to structurally support itself and withstand applicable gravity loads under Chapter 3, and requires the roof it sits on to be designed and constructed to support the loads imposed by the system under Chapter 8. R909.3 then states that rooftop-mounted photovoltaic systems shall be installed in accordance with the manufacturer’s instructions and that “roof penetrations shall be flashed and sealed in accordance with this chapter.”

“This chapter” is Chapter 9. R903.2.1 requires flashings at wall and roof intersections, wherever there is a change in roof slope or direction, and around roof openings — and where the flashing is metal, it must be corrosion resistant and not less than 0.019 inch thick, which is No. 26 galvanized sheet. A solar standoff is a roof opening. It is held to that standard, not to a lesser one.

Does a panel array change what the roof structure has to carry?

Yes, and in a way that surprises people: the code removes roof live load under the panels, but still requires the structure to work for the case where the panels are not there.

Section R324.4.1 provides that roof structures supporting photovoltaic panel systems shall be designed for applicable roof live load, that the design “need not include roof live load in the areas covered by photovoltaic panel systems,” and that portions of the roof not covered by panels shall be designed for roof live load. It then adds the part that gets missed: roof structures supporting a photovoltaic panel system “shall be designed for live load, L_R, for the load case where the photovoltaic panel system is not present.” In plain terms, the framing has to pass both with the array and without it — which matters the day the array comes off for a re-roof.

What about solar shingles rather than mounted panels?

Different section, stricter roofing rules. Photovoltaic shingles are a roof covering, so they land in R905.16 with a minimum slope, a deck requirement and an ice barrier rule.

R324.5 routes building-integrated photovoltaic systems that serve as roof coverings to Section R905, and R324.5.1 sends photovoltaic shingles specifically to R905.16. There, R905.16.2 limits photovoltaic shingles to roof slopes of 2:12 or greater. R905.16.1 requires a solid or closely-fitted deck unless the covering is specifically designed for spaced sheathing. R905.16.3 requires underlayment conforming to ASTM D4869 or ASTM D6757, applied shingle fashion from the eave and lapped 2 inches under R905.16.4. And R905.16.4.1 carries the ice barrier rule: in areas with a history of ice forming along the eaves causing a backup of water, as designated in Table R301.2(1), an ice barrier of two cemented layers of underlayment or a self-adhering polymer modified bitumen sheet must run from the lowest edges of all roof surfaces to a point not less than 24 inches inside the exterior wall line, with an exception for detached accessory structures containing no conditioned floor area.

If you want the broader Kentucky ice-barrier picture, we covered it separately in when an ice barrier is required on a Kentucky roof.

Where do solar-related leaks actually show up on a repair call?

At the attachment points and the transitions around them — the same places the code singles out, for the same reason.

Speaking generally about the craft rather than about any one job: a penetration that was sealed instead of flashed will hold for a while and then stop, because sealant is a maintenance item and flashing is a water-management detail. The code’s own language separates them — R909.3 says flashed and sealed, not sealed. The related details worth checking at the same time are wall intersections and slope changes under R903.2.1, and the cricket requirement in R903.2.2 for any penetration more than 30 inches wide measured perpendicular to the slope. Our notes on kick-out flashing under the Kentucky code and on valley and wall flashing repair cover those two details directly.

Central Roof Repair works on the roof side of this: diagnosing and repairing leaks at existing penetrations, and advising on roof condition before an array goes on or comes off. Electrical work and panel installation belong to a licensed electrical and solar contractor under NFPA 70, which R909.1 and R324.3 both reference.

Section	What it governs
R909.1–R909.3	Rooftop-mounted PV: compliance, structural support, installation and penetration flashing
R324.4.1	Roof live load with and without the array present
R324.5 / R905.16	Building-integrated PV and photovoltaic shingles as a roof covering
R905.16.2	Photovoltaic shingles limited to 2:12 slope or greater
R903.2.1 / R903.2.2	Flashing locations and metal thickness; cricket over penetrations wider than 30 inches

Is caulk alone enough at a solar mount?

The code language is “flashed and sealed in accordance with this chapter” (R909.3), and Chapter 9’s flashing requirements in R903.2.1 specify locations and, for metal flashing, a minimum thickness of 0.019 inch. Sealant on its own does not satisfy a flashing requirement.

Do photovoltaic shingles work on a low-slope roof?

Not below 2:12. R905.16.2 states that photovoltaic shingles shall be used only on roof slopes of two units vertical in 12 units horizontal or greater.

Does the code require a cricket above a solar array?

R903.2.2 requires a cricket or saddle on the ridge side of any chimney or penetration more than 30 inches wide measured perpendicular to the slope. Whether a particular array or its attachments meet that description is a question for the installer and the local building official; the rule is written about penetration width, not about panel type.

Last updated: October 18, 2026. Code sections are from the Kentucky Residential Code as adopted from the 2015 IRC; the Commonwealth publishes the code through the Kentucky Department of Housing, Buildings and Construction. General consumer background on rooftop solar is published by the U.S. Department of Energy’s Homeowner’s Guide to Going Solar. Sections read October 18, 2026.

Disclosure: Marcos Gil owns Central Property Services and publishes marcosgilrealty.com and Invest in the Gorge.

By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Corridor Roof Report · Storm Record

Hail gets the attention and wind does the damage. In the federal storm record for Kentucky in 2025, wind events outnumbered hail events 740 to 262 — about 2.8 to 1 — and in Madison County the split was 12 wind events to 3 hail. If you are checking a roof after a storm, wind is statistically the more likely culprit, and it does not leave the marks people are looking for.

Does wind or hail cause more storm events in Kentucky?

Wind, by a wide margin. NOAA’s Storm Events Database logged 740 wind-type events across Kentucky in 2025 against 262 hail events — roughly 2.8 wind events for every hail event.

Broken out, that is 677 thunderstorm wind events plus 61 strong-wind events and the remainder high wind. Recorded wind magnitudes ran from 35 knots (about 40 mph) at the low end to 83 knots (about 96 mph) at the high end, with a median of 50 knots — roughly 58 mph. Recorded hail ran to a maximum of 4.50 inches, with a median of 1.00 inch, which is the classic quarter-sized stone.

Here is how 2025 fell across the counties we work in. Read it with the caveat in the next section firmly in mind.

County	Wind events	Hail events	Tornado
Madison	12	3	0
Estill	11	1	0
Wolfe	9	2	0
Garrard	9	1	1
Powell	8	0	0
Montgomery	7	0	0
Fayette	6	2	0
Scott	5	1	0
Lee	4	0	0
Bourbon	2	0	0
Clark	1	0	0
Woodford	1	1	0
Jessamine	0	0	1

Why does Fayette County show fewer events than Madison or Estill?

Because this is a record of reported events, not of weather. A storm only enters the database when someone observes and reports it, so county counts mix real storm frequency with reporting density.

This is the single most important caveat on the table above, and I would rather lead with it than bury it. Fayette County showing 6 wind events while Estill County showed 11 does not establish that Estill is windier. Rural counties with spotter networks and open terrain sometimes generate more reports than a dense urban county where the same gust passes between buildings unremarked, and the reverse happens too. The honest reading is: wind events are recorded across every county we serve, in the high single digits to low teens per year, and the wind-to-hail ratio is lopsided everywhere. Do not read a league table into it.

What the counts are genuinely good for is calibrating expectations. A homeowner who has lived in Madison County for ten years has probably sat through something in the order of a hundred recorded wind events and a couple of dozen hail events. That is the exposure history the roof above them actually has.

What does wind damage look like compared with hail?

Hail bruises the field of the shingle in a random scatter. Wind works the edges and the seal strip, so the damage follows lines — rakes, ridges, eaves and the windward slope.

The practical difference, and the reason wind claims get missed, is that the two failures present completely differently:

• Hail leaves impact marks distributed across the slope with no particular regard for geometry, often with matching marks on soft metal — vents, gutters, flashing, the top of an air conditioner. That collateral evidence on metal is what makes a hail event easy to confirm from the ground.
• Wind breaks the adhesive seal between shingle courses. Once the seal is broken, the shingle is loose whether or not it looks it, because it falls back into position when the wind drops. The marks to look for are along edges and transitions: lifted or missing tabs at the rake and eave, creased shingles, exposed nail heads, displaced ridge cap, and damage concentrated on one slope rather than scattered over all of them.
• Both can leave a roof that looks entirely normal from the driveway. Neither diagnosis should be made from a photograph taken from the ground, and I would not make one from one.

The craft point I would pass on to any homeowner is about sequencing, not technique. After a wind event the useful question is not “is anything missing” — missing shingles are the easy case and you can usually see them. The useful question is “is anything still sealed.” A roof can lose none of its shingles and most of its wind resistance in the same storm, and the next ordinary gust is the one that takes them off. That is why we treat a recorded wind event as a reason to look, not a reason to wait for a leak. A leak is the late symptom; a broken seal is the early one. The same logic drives the checklist in what to do after the storm, and wind damage roof repair covers what the repair itself involves.

What I will not put a number on is cost. Material prices and crew availability in Central Kentucky move, and a figure invented here would be worse than none. Any real number comes from looking at the specific roof.

Which month has the most wind events in Kentucky?

In 2025 the record was heavily concentrated in spring: 289 wind events in May, 142 in March and 125 in April. The one figure that surprises people is December, with 32 — more than June’s 92 would suggest for a winter month, and well above February’s 6. Winter wind is not a small category in Kentucky.

Does a recorded event in my county mean my roof was damaged?

No. A county-level event means a report came from somewhere in the county, which can be many miles from any given address. It is a reason to have a look, not evidence of damage at a specific property, and it is not a basis for an insurance claim on its own.

Is 58 mph enough to damage shingles?

The median recorded magnitude in 2025 was 50 knots, about 58 mph, which is squarely in the range where seal-strip failure and tab lifting occur on asphalt shingles — particularly on older roofs where the adhesive has aged, at edges and corners where uplift concentrates, and where the original installation was short on nails or had them placed high. Whether a specific roof was affected depends on its age, its condition and its exposure, which is an inspection question rather than a wind-speed question.

Source: NOAA National Centers for Environmental Information, Storm Events Database, Kentucky records for calendar year 2025, from the detail file released August 19, 2026 and read October 17, 2026.

Last updated: October 17, 2026.

Disclosure: Central Roof Repair is owned by Marcos Gil, who also owns Central Property Services and publishes marcosgilrealty.com and investinthegorge.com. By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Central Roof Repair · Kentucky code

A chimney cricket is required in Kentucky by a single sentence of code, and the sentence is stricter than the rule most people quote. It applies to any chimney or penetration more than 30 inches wide, it tells you to measure that width perpendicular to the slope, and a second sentence limits what the cricket may be covered with. If your chimney is the leak, this is the check that decides whether flashing alone was ever going to hold.

Last updated: October 12, 2026

When does Kentucky’s code require a chimney cricket?

When the chimney or penetration is more than 30 inches wide, measured perpendicular to the roof slope. The cricket goes on the ridge side — the uphill side — of it.

Section R903.2.2 of the residential code Kentucky has adopted reads: “A cricket or saddle shall be installed on the ridge side of any chimney or penetration more than 30 inches (762 mm) wide as measured perpendicular to the slope. Cricket or saddle coverings shall be sheet metal or of the same material as the roof covering.” That is the whole requirement, and it carries three details worth separating out.

Detail one: measured perpendicular to the slope

The width that counts is across the slope, not up it. A chimney that is 24 inches across the face and 40 inches deep going up the roof is not over the line; the same chimney turned ninety degrees is. This is the measurement people get backwards from the ground, and it is the reason two chimneys that look identical from the driveway can land on opposite sides of the rule.

Detail two: “or penetration” is not a throwaway phrase

The section is titled for crickets and saddles and most writing about it says “chimney.” The code text says “any chimney or penetration.” A wide mechanical curb, a built-up curb for equipment, a framed dormer cheek wall or any other obstruction more than 30 inches across the slope is inside the same sentence. If water has to choose a side to go around something that wide, the code wants a diverter built, not a bigger bead of sealant.

Detail three: what the cricket may be covered with

The second sentence is the one almost nobody quotes: cricket or saddle coverings “shall be sheet metal or of the same material as the roof covering.” Two options, and that is the list. A cricket framed correctly and then finished in a material that is neither sheet metal nor the roof covering itself does not meet the sentence, however well it sheds water on the day it is built.

In practice that is why you see crickets either shingled over with the field shingles or formed in metal. Both are compliant. Both also depend on the flashing underneath them being right, which is a separate section and a separate failure — the kick-out flashing requirement is the usual companion problem on a chimney that sits near a wall.

The one exception the code writes down

Unit skylights are carved out: those installed in accordance with Section R308.6 and flashed in accordance with the manufacturer’s instructions “shall be permitted to be installed without a cricket or saddle.” A wide skylight is the one penetration over 30 inches that does not need one — provided both halves of that exception are satisfied, the installation standard and the manufacturer’s flashing instructions.

Condition	Cricket required?
Chimney 30 inches or less wide across the slope	No, not by R903.2.2
Chimney more than 30 inches wide across the slope	Yes, on the ridge side
Any other penetration more than 30 inches wide across the slope	Yes — the text says “chimney or penetration”
Unit skylight per R308.6, flashed per the manufacturer	No — the stated exception
Covering made of something other than sheet metal or the roof covering	Not compliant with the second sentence

Which rulebook this comes from in Kentucky

815 KAR 7:125, Section 2(1), makes the 2015 International Residential Code the mandatory state residential building code for single-family dwellings, two-family dwellings and townhouses in Kentucky, “except that the Kentucky amendments in the 2018 Kentucky Residential Code shall supersede any conflicting provision in the 2015 IRC.” The state’s own published edition is the 2018 Kentucky Residential Code, Third Edition from the Department of Housing, Buildings and Construction. So the right answer to “which code?” is: the 2015 IRC, read through Kentucky’s amendments.

One more line from the same regulation changes who ever checks. Section 2(2)(a) says permits, inspections and certificates of occupancy “shall not be required for a single-family dwelling unless required by local ordinance.” The code applies statewide; the inspection is a local decision. That is the whole reason a homeowner can end up with a non-compliant chimney detail and no paperwork anywhere saying so — covered further in whether a re-roof needs a permit in Central Kentucky and which rulebook applies in Lexington.

What we look at on a chimney leak

General craft, not a diagnosis of your roof: on a wide masonry chimney the water almost never comes through the front face. It stacks up on the uphill side, sits against the brick behind a wedge of debris, and finds the step flashing laps from above rather than below. A cricket removes the place where the water is allowed to stop. That is why a repair that only replaces flashing on a chimney over 30 inches wide tends to buy a season rather than fix a cause, and why the first measurement we take is the one across the slope.

If the chimney is the suspected source, the other two things worth looking at the same morning are the condition of the counterflashing where it enters the masonry joint and the underlayment immediately uphill. Chimney flashing repair and underlayment requirements on a low-slope shingle roof cover those two separately.

Is a cricket the same thing as a saddle?

The code uses both words for the same requirement — “a cricket or saddle” — so either term satisfies the section. In the field, cricket is the word most roofers use.

Does this apply to a re-roof, or only new construction?

R903.2.2 is a requirement of the residential code that Kentucky has adopted statewide; whether it is inspected on your job depends on whether your city or county requires permits and inspections, which 815 KAR 7:125 Section 2(2)(a) leaves to local ordinance for single-family dwellings. The building official having jurisdiction decides code questions on a specific roof.

My chimney is exactly 30 inches wide. Do I need one?

The text says “more than 30 inches,” so 30 inches even is not over the threshold. Measure across the slope, and measure the chimney, not the flashing.

Sources: Sections R903.2.2 and R903.3 of the 2015 International Residential Code as adopted for Kentucky, read October 12, 2026; adoption, supersession and the local-ordinance exception at 815 KAR 7:125, Section 2, Kentucky Legislative Research Commission; 2018 Kentucky Residential Code, Third Edition, August 2024, Kentucky Department of Housing, Buildings and Construction. Code text quoted as published. General information about Kentucky code requirements, not a code interpretation — the building official having jurisdiction decides that. Central Roof Repair is owned by Marcos Gil, who also publishes marcosgilrealty.com and investinthegorge.com.

By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Central Roof Repair · Kentucky code

A roof re-cover — new covering installed over the old one, no tear-off — is permitted in Kentucky in four situations and forbidden in three. The three that forbid it are short, specific and easy to check from the ground: a water-soaked or deteriorated existing roof, a slate or tile covering, or a roof that already carries two or more applications of any type. Section R908 of the residential code Kentucky has adopted says so in about a hundred words.

Last updated: October 11, 2026

When is a roof re-cover not allowed in Kentucky?

Three conditions, any one of which forces a tear-off: a water-soaked or deteriorated base, slate or tile, or a roof already carrying two or more layers.

Section R908.3.1.1 is titled “Roof Re-cover Not Allowed,” and it lists them without qualification. A re-cover is not permitted “where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing”; “where the existing roof covering is slate, clay, cement or asbestos-cement tile”; or “where the existing roof has two or more applications of any type of roof covering.”

Read the third one carefully, because it is the one that catches most Central Kentucky houses. It says two or more applications of any type — not two layers of shingles. A shingle roof laid over an original roll-roofing or shake layer is already at two, and the next covering has to come off everything. The count is of applications, not of the material you can see.

When does the code permit a re-cover?

Four situations, in R908.3.1 — manufacturer-approved installation, a self-supporting system such as standing-seam metal, specific coverings over wood shake, and a coating over spray foam.

Section R908.3.1 permits installing a new roof covering over an existing one where any of the following occur: where the new covering “is installed in accordance with the roof covering manufacturer’s approved instructions”; where “complete and separate roofing systems, such as standing-seam metal roof systems, that are designed to transmit the roof loads directly to the building’s structural system and do not rely on existing roofs and roof coverings for support” are used, which “shall not require the removal of existing roof coverings”; where “metal panel, metal shingle and concrete and clay tile roof coverings” are installed over existing wood shake roofs in accordance with Section R908.4; and where “a new protective coating over an existing spray polyurethane foam roofing system” is applied, which is “permitted without tear-off of existing roof coverings.”

The wood-shake route carries a condition that is easy to miss. R908.4 says that where the new covering over wood shingle or shake “creates a combustible concealed space, the entire existing surface shall be covered with gypsum board, mineral fiber, glass fiber or other approved materials securely fastened in place.” That is a fire-separation requirement wearing a reroofing label, and it is a real line item, not a detail.

Does a reroof have to meet the minimum slope for the new covering?

Not the quarter-inch-in-twelve drainage minimum, if the existing roof provides positive drainage. R908.1 carries that exception explicitly.

This is the most useful sentence in the whole section for a low-slope repair, and almost nobody quotes it. R908.1 requires reroofing materials and methods to comply with Chapter 9, then excepts two things. First: “Reroofing shall not be required to meet the minimum design slope requirement of one-quarter unit vertical in 12 units horizontal (2-percent slope) in Section R905 for roofs that provide positive roof drainage.” Second: “For roofs that provide positive drainage, re-covering or replacing an existing roof covering shall not require the secondary (emergency overflow) drains or scuppers of Section R903.4.1 to be added to an existing roof.”

In other words, an existing low-slope roof that actually drains does not have to be rebuilt to reach the design slope that a new roof of the same type would need. The minimums discussed in our notes on what the Kentucky code calls a flat roof versus a low-slope roof and on mineral-surfaced roll roofing’s slope floor are design-slope requirements in Section R905. R908.1 is the reroofing door out of the first of them where drainage is already working — and “provides positive roof drainage” is the condition that has to be true, which is a question about the existing roof, not about the product going on it.

What does a roof replacement actually include?

Removal of every existing layer down to the deck — with one exception for an adhered ice barrier membrane, which may stay and be covered.

R908.3: “Roof replacement shall include the removal of existing layers of roof coverings down to the roof deck.” The exception: “Where the existing roof assembly includes an ice barrier membrane that is adhered to the roof deck, the existing ice barrier membrane shall be permitted to remain in place and covered with an additional layer of ice barrier membrane in accordance with Section R905.” That matters here because Kentucky requires an ice barrier in the first place on eaves — see where the code requires an ice barrier on a Kentucky roof.

R908.2 sits underneath both paths: “the structural roof components shall be capable of supporting the roof covering system and the material and equipment loads that will be encountered during installation of the roof covering system.” That is a loads check for the install itself, not just the finished assembly — the reason a stack of bundles does not get staged in one spot on an old deck.

What can and cannot be reinstalled?

Sound slate, clay or cement tile may go back on. Damaged tile, rusted flashings and aggregate surfacing may not.

R908.5: “Existing slate, clay or cement tile shall be permitted for reinstallation, except that damaged, cracked or broken slate or tile shall not be reinstalled. Any existing flashings, edgings, outlets, vents or similar devices that are a part of the assembly shall be replaced where rusted, damaged or deteriorated. Aggregate surfacing materials shall not be reinstalled.” R908.6 adds that flashings “shall be reconstructed in accordance with approved manufacturer’s installation instructions,” and that “metal flashing to which bituminous materials are to be adhered shall be primed prior to installation.”

What you have	Re-cover?	Section
One layer, sound, manufacturer-approved for re-cover	Permitted	R908.3.1
Standing-seam metal carrying its own loads	Permitted, no removal required	R908.3.1
Metal panel, metal shingle or concrete/clay tile over wood shake	Permitted, with R908.4 fire separation	R908.3.1, R908.4
New coating over existing spray polyurethane foam	Permitted, no tear-off	R908.3.1
Water-soaked or deteriorated existing roof	Not allowed	R908.3.1.1
Slate, clay, cement or asbestos-cement tile covering	Not allowed	R908.3.1.1
Two or more applications of any covering	Not allowed	R908.3.1.1

Which code is this, exactly?

Kentucky’s mandatory residential code is the 2015 IRC, with the Kentucky amendments in the 2018 Kentucky Residential Code superseding any conflicting provision.

815 KAR 7:125, Section 2(1), is the adopting regulation: “Except as provided in subsection (2) of this section, the 2015 International Residential Code for One (1) and Two (2) Family Dwellings (IRC) shall be the mandatory state residential building code for all single-family dwellings, two (2) family dwellings, and townhouses constructed in Kentucky, except that the Kentucky amendments in the 2018 Kentucky Residential Code shall supersede any conflicting provision in the 2015 IRC.” Section 3(1) incorporates both documents by reference — the 2015 IRC and the 2018 Kentucky Residential Code, Third Edition, August 2024, published by the Kentucky Department of Housing, Buildings and Construction.

Two practical consequences. The R908 text above is the 2015 IRC base text; if a Kentucky amendment conflicts with any part of it, the amendment governs, and the amendment document is the one to check on a specific job. And Section 2(2)(a) is worth knowing before anyone argues about paperwork: “Permits, inspections, and certificates of occupancy shall not be required for a single-family dwelling unless required by local ordinance.” The code applies statewide; the enforcement does not, and whether anyone inspects your reroof is a local question.

How we count layers before quoting

Counting applications is the first thing worth doing on any reroof conversation, and it is cheaper than any other step. In general practice the count is read at the edges, not in the field — a rake, an eave, a gable return, or the cut at a pipe penetration shows the stack in cross-section where the surface never will. Two habits save arguments later. First, write the layer count on the quote with where it was observed, because “two or more applications of any type” is a factual finding that changes the scope and the price, and a finding without a location is an opinion. Second, treat a soft or spongy deck as a separate question from the layer count: R908.3.1.1’s first condition is about whether the existing roof is an adequate base, and that can fail on a single-layer roof. Neither habit is a code interpretation and we do not offer one — the building official does that. They just keep a quote from turning into a change order on the second morning.

Common questions about roofing over an existing roof

How many layers of roofing does Kentucky allow?

The code does not set a layer allowance so much as a stopping point. R908.3.1.1 forbids a re-cover “where the existing roof has two or more applications of any type of roof covering,” so a roof already at two cannot take a third by re-cover — it requires replacement down to the deck under R908.3. A single sound layer may be re-covered where one of the R908.3.1 conditions is met.

Can metal go over an existing shingle roof without tear-off?

R908.3.1 permits a re-cover where “complete and separate roofing systems, such as standing-seam metal roof systems, that are designed to transmit the roof loads directly to the building’s structural system and do not rely on existing roofs and roof coverings for support” are installed, and says those “shall not require the removal of existing roof coverings.” The R908.3.1.1 prohibitions still apply on top of that, so a two-layer or water-soaked roof is out regardless of the system chosen.

Does my low-slope roof have to be rebuilt to reach the code slope on a reroof?

Not for the quarter-unit-in-twelve drainage minimum, if the roof provides positive drainage. R908.1 excepts reroofing from that Section R905 design-slope requirement for roofs that drain, and also says secondary emergency-overflow drains or scuppers under R903.4.1 need not be added to an existing roof that drains. Whether your roof actually provides positive drainage is a site finding, and the building official has the final word where a permit is required.

Sources: Sections R908.1 through R908.6 of the 2015 International Residential Code as adopted for Kentucky, read October 11, 2026; adoption and incorporation by reference at 815 KAR 7:125, Sections 2 and 3, Kentucky Legislative Research Commission; 2018 Kentucky Residential Code, Third Edition, August 2024, Kentucky Department of Housing, Buildings and Construction. Code text quoted as published. General information about Kentucky code requirements, not a code interpretation — the building official having jurisdiction decides that.

By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Central Roof Repair · Kentucky code

Mineral-surfaced roll roofing is permitted on slopes down to 1 in 12 — an 8 percent slope. That is the lowest minimum of any non-membrane roof covering in the residential code Kentucky has adopted, and it is half the minimum slope asphalt shingles require.

There is a narrow band of roof — steeper than a flat roof, shallower than a shingle roof — where a lot of Central Kentucky homeowners get told two contradictory things. A porch roof, a shed-roof addition, a low dormer tie-in. Shingles are not permitted down there. A full membrane feels like overkill for eighty square feet. The code has an answer for that band, and it is the covering almost nobody brings up.

What is the minimum slope for mineral-surfaced roll roofing in Kentucky?

One unit vertical in twelve horizontal. Section R905.5.2 states that mineral-surfaced roll roofing “shall not be applied on roof slopes below one unit vertical in 12 units horizontal (8-percent slope).”

That is the code floor, not a recommendation, and it sits well below the 2:12 floor for asphalt shingles in Section R905.2.2. Both sections live in Chapter 9 of the International Residential Code, readable at the Kentucky IRC 2015, Chapter 9, Roof Assemblies.

Which version of the code applies in Kentucky?

The 2015 IRC, as amended. Kentucky’s residential code regulation adopts the 2015 edition and lets the Kentucky amendments override it where the two conflict — not the 2018 or 2021 edition most national articles quote.

The regulation says it directly: under 815 KAR 7:125, Kentucky Residential Code, “the 2015 International Residential Code for One (1) and Two (2) Family Dwellings (IRC) shall be the mandatory state residential building code for all single-family dwellings, two (2) family dwellings, and townhouses constructed in Kentucky, except that the Kentucky amendments in the 2018 Kentucky Residential Code shall supersede any conflicting provision in the 2015 IRC.”

This matters more than it sounds. Search for a roof slope minimum and most of what comes back cites the 2018 or 2021 IRC. The roll-roofing section numbers happen to line up across editions, so you can land on the right answer from the wrong book — but that is luck, not method. The book that governs a Kentucky permit is the 2015 IRC plus the Kentucky amendments, and the local building official is the one who reads it.

Where does 1:12 sit against every other roof covering?

Between the membranes and the shingles. The membrane systems go lower, at a quarter unit in twelve; everything in the shingle family needs 2:12 or more. Roll roofing is alone in the gap.

Roof covering	Section	Minimum slope
Built-up roof (other than coal-tar)	R905.9.1	1/4 : 12 — 2% design slope for drainage
Modified bitumen membrane	R905.11.1	1/4 : 12 — 2%
Thermoset single-ply (e.g. EPDM)	R905.12.1	1/4 : 12 — 2%
Thermoplastic single-ply (e.g. TPO, PVC)	R905.13.1	1/4 : 12 — 2%
Mineral-surfaced roll roofing	R905.5.2	1 : 12 — 8%
Asphalt shingles	R905.2.2	2 : 12 (double underlayment from 2:12 to 4:12)
Photovoltaic shingles	R905.16.2	2 : 12
Clay and concrete roof tile	R905.3.2	2 1/2 : 12
Metal roof shingles	R905.4.2	3 : 12 — 25%
Metal roof panels, lapped non-soldered seam without applied lap sealant	R905.10.2	3 : 12 — 25%
Wood shingles	R905.7.2	3 : 12 — 25%
Wood shakes	R905.8.2	3 : 12 — 25%
Slate and slate-type shingles	R905.6.2	4 : 12 — 33%

Does the code minimum settle it?

No — and this is the part that trips people up. Section R905.5.5 requires installation “in accordance with this chapter and the manufacturer’s instructions,” so a product rated to a steeper minimum than 1:12 governs over the code floor.

Read that way, R905.5.2 and R905.5.5 work as a pair: the code sets the lowest slope the code will ever allow, and the manufacturer sets the lowest slope that product will ever allow. The stricter of the two is the real answer for a specific roof. Which means “code says 1:12” is only half an answer until somebody has named the actual material and read its instructions. On a shallow porch roof that distinction decides whether the job is compliant or whether it is a leak with a warranty disclaimer attached.

What else does R905.5 require?

Four more things, and one of them surprises people: ice barriers apply to roll roofing too.

• Solid sheathing (R905.5.1). “Mineral-surfaced roll roofing shall be fastened to solidly sheathed roofs.” No spaced decking.
• Underlayment (R905.5.3). Per Section R905.1.1 — for roll roofing, Table R905.1.1(1) calls out ASTM D226 Type I or II, or ASTM D4869 Type I, II, III or IV.
• Ice barrier (R905.5.3.1). Where required, per Section R905.1.2 — and R905.1.2 names mineral-surfaced roll roofing explicitly in its list of coverings. Our walk-through of when an ice barrier is required under Kentucky’s roof code covers how that requirement gets triggered locally.
• Material standard (R905.5.4). The product must conform to ASTM D3909 or ASTM D6380, Class M. That is a specification you can ask a contractor to point to on the wrapper.

In my own experience the conversation that produces this question almost never starts with the covering. It starts with a homeowner who has been told their porch roof “can’t be shingled” and has no idea what the alternative is, or with a roof that was shingled at 1.5:12 by somebody who did not measure. The slope is the first thing to establish, with a level and a tape, before anyone talks about material. Everything in the table above follows from that one number.

If you are trying to work out which category your roof falls into, start with flat versus low-slope roofs under Kentucky’s code, and if you are in the 2:12 to 4:12 band instead, see when a low-slope shingle roof needs double underlayment in Kentucky.

Is mineral-surfaced roll roofing the same thing as “rolled roofing”?

“Rolled roofing” is a loose shop term that gets used for several products. The code term is specific: Section R905.5 governs mineral-surfaced roll roofing, and R905.5.4 ties it to ASTM D3909 or ASTM D6380, Class M. Smooth-surfaced and saturated-felt roll products are not the same thing and are not what R905.5 permits at 1:12.

Can shingles be used below 2:12 if extra underlayment is added?

No. R905.2.2 sets 2:12 as the floor for asphalt shingles and requires double underlayment only in the 2:12-to-4:12 range. Below 2:12 the extra underlayment does not buy permission — the covering itself has to change.

Who decides whether a particular repair needs a permit?

The local building official with jurisdiction over the address. 815 KAR 7:125 sets the statewide code, but permits, inspections and certificates are handled locally, and requirements differ between a city with its own inspection program and an unincorporated area. Ask before the work starts, not after.

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Last updated: October 10, 2026

Need a slope measured and an honest answer about what the code allows on it? Call or text (859) 310-1209, or use the Central Roof Repair contact page.

By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Code summaries are educational and are not a substitute for a determination by the building official with jurisdiction over your address. Central Roof Repair is owned by Marcos Gil, who also publishes marcosgilrealty.com, forsalelexingtonky.com and investinthegorge.com.

Central Roof Repair · Code & Craft

On a shingle roof in Kentucky, double underlayment is required anywhere the slope runs from 2:12 up to 4:12 — which is most porch roofs, most additions and most low garage planes in Central Kentucky. The code does not treat that as an upgrade or a best practice. It is the same section that lets asphalt shingles be used on that slope at all, and the two layers go on in a specific, measurable way that is easy to verify from the ground once you know what to look for.

Where does the double underlayment requirement start and stop?

From 2:12 up to 4:12, two layers are required. At 4:12 and steeper, one layer is permitted. Below 2:12, asphalt shingles are not allowed at all.

Section R905.2.2 states that asphalt shingles “shall be used only on roof slopes of two units vertical in 12 units horizontal (2:12) or greater,” and that “For roof slopes from two units vertical in 12 units horizontal (2:12) up to four units vertical in 12 units horizontal (4:12), double underlayment application is required in accordance with Section R905.1.1.” The governing document in this state is the Kentucky Department of Housing, Buildings and Construction publication of the 2018 Kentucky Residential Code, Third Edition, August 2024.

Three slope bands, three different answers, and the line between the first two is a single unit of rise. A 4:12 main roof and a 3:12 porch tied into it are not the same roof as far as the code is concerned, even though they are usually quoted as one.

What does the two-layer application actually look like?

A 19-inch strip at the eave first, then full 36-inch-wide sheets running up the plane, each one overlapping the last by 19 inches.

Table R905.1.1(2), Underlayment Application, sets it out for asphalt shingles: for the 2:12 to 4:12 band, “underlayment shall be two layers applied in the following manner: apply a 19-inch strip of underlayment felt parallel to and starting at the eaves. Starting at the eave, apply 36-inch-wide sheets of underlayment, overlapping successive sheets 19 inches.” For 4:12 and greater it is “one layer… applied shingle fashion, parallel to and starting from the eave and lapped 2 inches.” End laps are 4 inches and “shall be offset by 6 feet.” Where the ultimate design wind speed is 140 mph or greater, the same applications apply “except all laps shall be not less than 4 inches.” Source: the 2018 Kentucky Residential Code as published by the state.

Now do the arithmetic, because this is where the requirement stops being a rule and starts being a quantity. A 36-inch sheet lapped 19 inches exposes 17 inches of new deck per course. Every point on that plane therefore ends up under two plies of underlayment, and the roll goes about twice as far up the slope as it would at a 2-inch lap. That is the entire mechanism: on a low slope, water moves slowly and wind-driven rain can push uphill under the shingle, so the code stops relying on the shingle as the only water-shedding layer and makes the underlayment continuous instead.

Why does this show up as a bid problem?

Because the low-slope plane costs materially more underlayment per square than the main field, and a bid that prices the whole roof at one rate has either absorbed that or skipped it.

This is the observation I would offer anyone reading two roofing quotes side by side. You cannot see underlayment once shingles are on, so it is the cheapest thing on a roof to leave out and the most expensive thing to discover later. Ask one question: what slope is the porch, and how many layers of underlayment is it getting? A roofer who knows the answer will give you a slope figure and a layer count without hesitating, because it is the number they used to order material. A quote that treats a 3:12 porch and a 6:12 main roof as the same line item is not necessarily a bad quote, but it is an unanswered question, and the answer changes the material order. Which category the code puts your roof in is the first thing to settle, because everything else follows from the slope.

Does the self-adhered alternative change any of this?

The code does allow an alternative, but it is conditional — and the conditions are the manufacturer’s instructions, not the installer’s judgement.

Section R905.1.1 permits, as an alternative, “self-adhering polymer-modified bitumen underlayment complying with ASTM D1970 installed in accordance with both the underlayment manufacturer’s and roof covering manufacturer’s instructions for the deck material, roof ventilation configuration and climate exposure for the roof covering to be installed.” The same section requires that underlayment complying with ASTM D226, D1970, D4869 and D6757 “bear a label indicating compliance to the standard designation and, if applicable, type classification.”

Two practical consequences follow from that wording. First, “in accordance with both” means two sets of instructions have to agree — the membrane’s and the shingle’s — and that is a documentation question a homeowner can reasonably ask to see. Second, the labelling requirement means the product on the truck is supposed to identify itself. If a crew is installing an unlabelled synthetic and calling it equivalent, the code’s own test for equivalence is not being met. The related requirement that catches most low-slope porches in this state is the ice barrier at the eave, and on a reroof the permit question is worth settling in the same conversation.

Is double underlayment the same thing as an ice barrier?

No. They are separate requirements that often land on the same porch. Double underlayment is a slope-driven requirement for the whole low-slope plane; an ice barrier is an eave-and-overhang requirement driven by climate. A roof can need both, and satisfying one does not satisfy the other.

Can I tell from the ground whether my porch is under 4:12?

Often, roughly. The practical test is rise over a 12-inch horizontal run measured on the rake or against a level — and the band that matters here is narrow, so a plane that looks “almost flat” next to a 6:12 or 8:12 main roof is usually in the 2:12 to 4:12 range. If it is genuinely close to the line, measure it rather than guess, because the requirement changes on one unit of rise.

What if the plane is below 2:12?

Then asphalt shingles are not the right covering at all — R905.2.2 limits them to 2:12 and greater. A plane below that needs a covering the code permits at low slope, which is a different repair and a different material conversation, not a thicker underlayment.

Last updated: October 8, 2026.

By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Central Roof Repair · Hiring & Contracts

You do not have to take a contractor’s word for it when you verify a roofing contractor’s workers’ comp in Kentucky. The Department of Workers’ Claims publishes a free Insurance Coverage Lookup you can search by employer name, city, postal code or FEIN — and the same tool lets you subscribe to be notified for a year if the policy you looked up is cancelled. That second feature is the one almost nobody uses, and on a multi-week roof it is the one that matters.

How do you check a roofer’s workers’ comp coverage in Kentucky?

Search the Department of Workers’ Claims Coverage Lookup by the company’s name. You can narrow by city, postal code, FEIN or employer ID if you have one.

Those are the search fields published on the Kentucky Department of Workers’ Claims Coverage Lookup page, read on October 7, 2026: employer name, city, postal code, FEIN and ID number. The page describes itself as a tool to check workers’ compensation coverage on a company doing business in Kentucky and its locations, and it returns the carrier and policy number for the coverage on file.

Can you be told if the coverage lapses later?

Yes. The lookup page states you may subscribe to coverage lapse notices by selecting policies and giving an email address, and you will be notified for one year.

The Kentucky Department of Workers’ Claims page says it plainly: “You may subscribe to Coverage Lapse Notices by selecting policies and providing your email address for notifications. For one year, you will be notified if the selected policy is cancelled or has locations removed.” The page frames it as a tool a contractor can use on a subcontractor — but nothing on it restricts the subscription to contractors.

Why might a legitimate contractor not show up yet?

Because the filing is allowed a ten-day window. Kentucky law gives the carrier ten days after a policy is issued to file the evidence of coverage with the department.

Under KRS 342.340, every employer must either insure its liability for workers’ compensation with an authorized carrier or satisfy the commissioner of its financial ability to pay directly, and any carrier or self-insured group providing coverage for a Kentucky location must file evidence of the employer’s compliance on the employer’s behalf. The statute sets the timing: “The filing shall be made within ten (10) days after the issuance of a policy, endorsement to a policy, or similar documentation of coverage.” The current version is effective July 15, 2014.

That ten-day window is the honest caveat on this whole method, and it cuts both ways. A roofer who bought a policy last Tuesday can be fully insured and still be invisible in the lookup today. So a blank result is not proof of no coverage — it is a reason to ask for the policy number and the carrier and check again in a couple of weeks. A clean row of nothing is far more often a timing artifact than a finding.

What does the statute require when coverage ends?

Notice from both sides. The employer must immediately notify the department of a cancellation and its date and reasons, and the carrier must do the same.

KRS 342.340 requires an employer that has cancelled its insurance or its membership in an approved self-insured group to immediately notify, or have notice given on its behalf to, the department of the cancellation, the date and the reasons; the carrier or self-insured group must give like notice upon cancellation, lapse, termination, expiration by reason of termination of the policy period, or nonrenewal. The statute also provides that termination of a policy issued under the chapter “shall take effect no greater than ten (10) days prior to the receipt of the notification by the commissioner” unless the employer has obtained other insurance and the new insurer notifies the commissioner.

Event	Who files	Timing in the statute
Policy issued or endorsed	Carrier or self-insured group, on the employer’s behalf	Within 10 days of issuance
Employer cancels coverage	Employer, or someone on its behalf	Immediately, with date and reasons
Cancellation, lapse, nonrenewal	Carrier or self-insured group	Like notice to the commissioner

How does this fit with asking for a certificate of insurance?

Ask for both. A certificate is the contractor’s document about a moment in time; the state lookup is a public record you can re-check and subscribe to without asking anyone.

The habit worth building is sequence, not paperwork volume. Before work starts, get the certificate and read the carrier name and policy number off it. Then put that company name into the state lookup and confirm the department has coverage on file. Then subscribe to the lapse notice for that policy, because the certificate you were handed cannot tell you anything about week three of the job. One detail in the statute is quietly useful here: it allows evidence of compliance filed with the department to include a named additional insured who has been provided proof of coverage by the employer — which is why asking to be named, rather than just shown a PDF, is a reasonable request to make.

Kentucky has no state roofing contractor licence to check instead, which is exactly why these records carry more weight here than they would elsewhere — our piece on what a Kentucky roofing contractor licence actually is covers what does and does not exist, and how to read a roofing estimate covers the document side of the same conversation. This is general information about public records and a statute, not legal advice; a Kentucky attorney is the person to consult on your own contract or claim.

Does every Kentucky roofing company have to carry workers’ compensation?

KRS 342.340 obliges “every employer under this chapter” either to insure its liability or to prove to the commissioner that it can pay compensation directly and post acceptable security. Whether a particular company is an employer under the chapter is a legal question about its own facts — which is one reason the lookup, showing what has actually been filed, is more useful than reasoning about the rule.

What do I do if the lookup shows no coverage on file?

Treat it as a question, not a verdict. Ask for the carrier and policy number, remember the statute’s ten-day filing window after issuance, and search again. If the company has been operating for a long time and nothing is on file under any spelling of its name or its FEIN, that is the point to stop and ask for an explanation in writing.

Is the lapse-notice subscription free, and how long does it last?

The page asks only for an email address and the policies you select, and states you will be notified for one year if a selected policy is cancelled or has locations removed. A roof is a short job and a year is a long subscription — the useful consequence is that one lookup covers the job and the warranty window that follows it.

Last updated: October 7, 2026.

By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Central Roof Repair · Code & Compliance

Asbestos roof removal in Kentucky is governed by a federal rule that most roofing conversations get backwards. Whether the asbestos regulations apply to your tear-off does not depend only on what the old roof is made of — it depends on the building, the square footage, and the machine used to take the roof off. EPA wrote a separate interpretive rule just for roofs, and Kentucky adopts that rule by name in 401 KAR 58:025, along with a state notification form that has to be submitted before the work starts.

Does the federal asbestos rule apply to a house roof?

No. The asbestos NESHAP does not cover roofing projects on single family homes or on residential buildings containing four or fewer dwelling units.

That exclusion comes from the definition of “facility” in 40 CFR 61.141, which reaches any institutional, commercial, public, industrial or residential structure — including buildings containing condominiums or individual dwelling units operated as a residential cooperative — but expressly excludes residential buildings having four or fewer dwelling units. EPA’s roof-removal interpretive rule states the consequence directly: the NESHAP does not cover roofing projects on single family homes or on residential buildings containing four or fewer dwelling units.

So a Richmond ranch house and a four-unit building are outside this rule. A church, a school, a strip retail building, a warehouse, an office building, and a five-unit apartment building are inside it. That line — four units — is where most of the confusion on a Central Kentucky job site starts.

Is asphalt roofing even an asbestos-containing material?

It can be, and the regulation names it. Asphalt roofing products containing more than one percent asbestos are Category I nonfriable asbestos-containing material.

The interpretive rule lists the asphalt roofing products that may contain asbestos: built-up roofing; asphalt-containing single ply membrane systems; asphalt shingles; asphalt-containing underlayment felts; asphalt-containing roof coatings and mastics; and asphalt-containing base flashings. Roofing products using other bituminous or resinous binders, such as coal tars or pitches, are also treated as Category I ACM.

Category II nonfriable ACM is everything else that is nonfriable — the examples given are asbestos-cement shingles, asbestos-cement tiles, and transite boards or panels containing more than one percent asbestos. The distinction is not academic. Category II material is generally more likely to become friable when damaged, and it is handled under a different threshold, below.

What turns a nonfriable roof into a regulated material?

The removal method. Category I nonfriable ACM becomes regulated asbestos-containing material once it has been, or will be, sanded, ground, cut or abraded.

“Regulated asbestos-containing material,” or RACM, is defined in 40 CFR 61.141 as friable asbestos material; Category I nonfriable ACM that has become friable; Category I nonfriable ACM that will be or has been subjected to sanding, grinding, cutting or abrading; or Category II nonfriable ACM that has a high probability of becoming, or has become, crumbled, pulverized or reduced to powder by the forces expected to act on it during the operation. An intact asbestos-containing built-up roof, left intact, is not RACM. The same roof cut into strips by a powered cutter is a different legal object.

What are the square-foot thresholds for a commercial roof?

Two numbers do the work: 160 square feet, and 5,580 square feet. Which one applies depends on whether the roofing is Category I or Category II, and on how it comes off.

Below 160 square feet of asbestos-containing roof area undergoing renovation, the interpretive rule says the NESHAP does not apply regardless of the removal method, the category of material, or its condition — although EPA still recommends methods that damage the material as little as possible. Above that, the rule splits by equipment.

EPA determined that where a rotating blade roof cutter, or equipment that similarly damages the roofing material, is used to remove Category I nonfriable asbestos-containing roofing, removal of 5,580 square feet of that material will create 160 square feet of RACM. So the agency’s interpretation is that an RB-roof-cutter project of 5,580 square feet or greater is subject to the NESHAP, and one below 5,580 square feet is not — except that notification is always required for demolitions.

Situation	Does the asbestos NESHAP apply?
Roof on a single-family home or a building with four or fewer dwelling units	No — outside the definition of “facility”
Less than 160 sq ft of asbestos-containing roof area	No, regardless of method, category or condition
Category I roofing, removed with an RB roof cutter, 5,580 sq ft or more	Yes
Category I roofing, removed with an RB roof cutter, under 5,580 sq ft	No — but notification is always required for demolitions
Category I roofing removed by slicing or other methods that do not sand, grind, cut or abrade	No, regardless of the area removed
Asbestos-cement shingles or other Category II roofing, 160 sq ft or more, where the method will crumble, pulverize, reduce to powder or contaminate that much material	Yes

The equipment definition is unusually precise, and it is worth reading before anyone buys or rents a machine. For purposes of the interpretive rule, an “RB roof cutter” means an engine-powered roof cutting machine with one or more rotating cutting blades whose edges are blunt. Equipment with blades having sharp or tapered edges, or which does not use a rotating blade, is used for slicing rather than cutting, and is not an RB roof cutter. EPA construes the rule to mean that if slicing or other methods that do not sand, grind, cut or abrade are used on Category I nonfriable ACM, the NESHAP does not apply regardless of the area of roof removed.

For scale, my own arithmetic on those two figures: 5,580 square feet is about 55.8 roofing squares, and 160 square feet is about 1.6 squares. A mid-sized commercial flat roof in Lexington or Richmond can sit on either side of the larger number, which is why the measurement and the method both belong in the scope of work rather than in a verbal agreement on the morning of the tear-off.

What does Kentucky add on top of the federal rule?

Kentucky adopts Subpart M and the roof-removal interpretive rule by name, and adds a state form that has to be submitted before renovation or demolition.

Section 2 of 401 KAR 58:025 requires owners and contractors of covered sources to comply with the applicable provisions of 40 C.F.R. 61.140 through 61.157, Subpart M; with the applicable provisions and requirements of “Appendix A to Subpart M of Part 61 — Interpretive Rule Governing Roof Removal Operations”; and with completion and submittal of Form DEP 7036 to the Division for Air Quality prior to renovation or demolition. Section 3 incorporates that form by reference as “Notification of Asbestos Abatement/Demolition/Renovation,” and lists the Division for Air Quality at 300 Sower Boulevard, Frankfort, Kentucky 40601, telephone (502) 564-3999, among the offices where the material may be inspected or obtained.

The fact that Kentucky names the roof interpretive rule in its own regulation matters. It means the 5,580-square-foot determination and the slicing distinction are not a federal footnote a state inspector might not reach for — they are part of the Kentucky requirement by direct reference.

What has to happen before anyone gets on the roof?

An inspection, then a notification. Both come before the work, and the inspection is required even where the thresholds turn out not to be met.

40 CFR 61.145(a) requires that, to determine which requirements apply and prior to the commencement of the demolition or renovation, the owner or operator thoroughly inspect the affected facility, or the part of it where the operation will occur, for the presence of asbestos — including Category I and Category II nonfriable ACM. There is no square-footage trigger on the inspection itself; the inspection is how you learn which square-footage rule you are in.

Where notification is required, the rule’s timing is specific: postmark or deliver the notice at least 10 working days before asbestos stripping or removal work, or any other activity begins, such as site preparation that would break up, dislodge or similarly disturb asbestos material. Ten working days is not ten days, and on a commercial reroof that difference usually lands on a Monday two weeks out.

How this changes a Central Kentucky commercial reroof

In practical terms, three things belong in the file before a tear-off is scheduled on any building bigger than a fourplex: the roof area measured, the inspection result for asbestos content, and a written description of the removal method. Those three facts together answer whether the project is regulated, and they are cheap to establish in advance and expensive to establish in retrospect. The pattern worth avoiding is the common one — a building owner who assumes an older low-slope roof is ordinary demolition debris because nobody asked, on a building whose age makes the question reasonable.

Asbestos abatement is separately regulated work and is not a line item a roofer absorbs. Where a roof is regulated, the inspection, the notification and the removal belong to parties licensed for that scope; the obligation under the federal rule sits with the owner or operator of the demolition or renovation activity. What a roofing contractor contributes is the measurement, the honest description of the method, and the willingness to stop and ask before the first cut.

Two related questions usually come up on the same job. Which rulebook governs the roof itself is covered in which roof code applies in Lexington, and whether the work needs a permit at all is covered in the re-roof permit under Central Kentucky and state code. For the scope itself, see commercial flat roof repair.

Central Roof Repair is owned by Marcos Gil, who also publishes marcosgilrealty.com and forsalelexingtonky.com. This is general information about federal and Kentucky asbestos requirements as published, not a regulatory determination and not legal advice; the Division for Air Quality and the authority having jurisdiction decide what applies to a specific building.

Does an older roof automatically contain asbestos?

No. The regulations are written around material containing more than one percent asbestos as determined by Polarized Light Microscopy, which is a laboratory determination rather than an assumption from the roof’s age. That is exactly why 40 CFR 61.145(a) requires a thorough inspection before the operation begins.

If the project is under the thresholds, is notification still needed?

For demolitions, the interpretive rule states that notification is always required, even where the area thresholds are not met. Kentucky’s own regulation separately requires completion and submittal of Form DEP 7036 to the Division for Air Quality prior to renovation or demolition. Confirm with the Division for Air Quality how those two requirements apply to a specific project.

Does the four-dwelling-unit exclusion apply to a condominium building?

Read the definition carefully. “Facility” in 40 CFR 61.141 expressly includes any structure or building containing condominiums or individual dwelling units operated as a residential cooperative, while excluding residential buildings having four or fewer dwelling units. A condominium building is addressed directly in the definition rather than treated as ordinary residential.

Last updated: October 6, 2026.

By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Central Roof Repair · Code & Compliance

Whether an ice barrier is required on a Kentucky roof is not a statewide yes or no. Kentucky’s residential code adopts the 2015 International Residential Code, and that code makes the ice barrier conditional — it is required only in areas with a history of ice forming along the eaves, “as designated in Table R301.2(1).” That table is filled in locally. So the honest answer to “is ice and water shield code here?” is: ask the building department that will inspect your roof, and ask them what their table says.

Which code book does a Kentucky re-roof answer to?

815 KAR 7:125 makes the 2015 International Residential Code Kentucky’s mandatory residential code, with the Kentucky amendments superseding any conflicting IRC provision.

The regulation is 815 KAR 7:125, Kentucky Residential Code, promulgated by the Department of Housing, Buildings and Construction under the mandate in KRS 198B.040(7) and KRS 198B.050 to maintain a mandatory uniform state building code. Section 3 of that regulation incorporates two documents by reference: the 2015 IRC published by the International Code Council, and the “2018 Kentucky Residential Code, Third Edition, August 2024.” The regulation became effective December 3, 2024.

Two practical consequences follow. First, the base text a Kentucky inspector reads for roof assemblies is the 2015 IRC, not the newest IRC edition a manufacturer’s literature may cite. Second, the Kentucky amendment document currently in force is the Third Edition dated August 2024 — worth knowing because older editions of the same 2018 Kentucky Residential Code are still in circulation as PDFs, including a Second Edition dated April 2019 that the state’s own document library still serves. If a bid, a letter or an adjuster’s report cites “the Kentucky code,” the useful follow-up question is which edition.

What does the ice barrier section actually require?

Where it is triggered, section R905.1.2 requires either two layers of cemented underlayment or a self-adhering polymer-modified bitumen sheet, run from the lowest roof edge to 24 inches inside the exterior wall line.

Three details inside that sentence are the ones that get missed on a Central Kentucky roof.

• It is measured from the wall line, not the eave. The requirement runs to a point not less than 24 inches inside the exterior wall line of the building. On a house with a deep overhang, 24 inches of membrane measured up from the drip edge does not reach the line the code is actually drawing.
• It is a covering-specific rule. The section lists the coverings it applies to: asphalt shingles, metal roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shingles and wood shakes.
• Two cemented layers is an accepted path. A self-adhering membrane is the common method, but the code also permits not fewer than two layers of underlayment cemented together.

So is it required in Lexington, Richmond or Mount Sterling?

That is a question for the authority having jurisdiction, because the trigger lives in a locally completed table rather than in the statewide regulation text.

I want to be precise about the limit of what I can verify here. 815 KAR 7:125 and the adoption chain are public and checkable, and I have linked them. The value entered in Table R301.2(1) for a specific Kentucky jurisdiction is not something I can responsibly assert from a regulation page, so I am not going to put a number or a yes/no on it. Call the building department that will issue the permit and ask two questions: what does your Table R301.2(1) say for ice barrier underlayment, and which edition of the Kentucky Residential Code are you enforcing. Both answers are free, and both are worth having in writing before a re-roof.

Worth noting separately: an ice barrier is a code question, not a performance guarantee. Whether your roof needs one as a matter of building science is a different conversation from whether an inspector will require one, and the two can point opposite directions on the same house. Our write-up on ice dams on Kentucky roofs and how to prevent them covers the building-science half, and which rulebook a Lexington re-roof answers to covers jurisdiction. If the decking under the eave is already soft, that is roof decking replacement territory before any membrane goes down.

A note on how this gets sold

In our repair work the phrase “ice and water shield is code” comes up constantly, usually in good faith, and it is close enough to true that nobody questions it. The professional habit worth keeping is to separate three claims that get collapsed into one: the code requires it here, the manufacturer requires it for warranty, and the roof needs it. Those are three different documents with three different answers, and a homeowner is entitled to know which one is driving the line item on the estimate. Manufacturer warranty terms in particular often exceed code, and a warranty requirement is a contract with the manufacturer, not a building regulation.

Is Kentucky on the 2015 IRC or a newer edition?

815 KAR 7:125 incorporates the 2015 International Residential Code, together with the 2018 Kentucky Residential Code, Third Edition, August 2024, whose Kentucky amendments supersede any conflicting 2015 IRC provision. The regulation took effect December 3, 2024.

Does the ice barrier rule apply to a metal roof?

R905.1.2 names metal roof shingles among the coverings it applies to. Standing-seam and other metal roof panel systems are a separate covering class in the code, so confirm which product class your roof falls into with the inspector rather than assuming.

If my jurisdiction does not require it, should I skip it?

Not necessarily — code is a minimum, not a recommendation. Eave detailing, insulation and ventilation on your specific roof drive whether ice backs up at all. That assessment belongs on the roof, not in a table.

Last updated: October 5, 2026

By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Central Roof Repair is owned by Marcos Gil, who also publishes marcosgilrealty.com and forsalelexingtonky.com. This is general information about Kentucky’s adopted residential code, not a code ruling and not legal advice; the authority having jurisdiction decides what applies to your roof.

Central Roof Repair · Code & Detailing

Kick-out flashing in Kentucky sits in an odd place: the residential code requires exactly what a kick-out does, and never uses the words “kick-out flashing.” That gap is why a homeowner can be told, truthfully, that the part is not named in the code — and be misled, because the function it performs is required.

Does the Kentucky residential code require kick-out flashing?

It requires the function and not the name. The code demands a flashing that diverts water away from the point where a sloped roof’s eave meets a vertical sidewall — which is the job a kick-out does.

Kentucky’s residential code is the 2015 International Residential Code, adopted by reference. 815 KAR 7:125 states that “the 2015 International Residential Code for One (1) and Two (2) Family Dwellings (IRC) shall be the mandatory state residential building code for all single-family dwellings, two (2) family dwellings, and townhouses constructed in Kentucky, except that the Kentucky amendments in the 2018 Kentucky Residential Code shall supersede any conflicting provision in the 2015 IRC.” That regulation was last amended effective December 3, 2024.

Inside that code, section R903.2.1 (Locations) reads: “Flashings shall be installed at wall and roof intersections, wherever there is a change in roof slope or direction and around roof openings. A flashing shall be installed to divert the water away from where the eave of a sloped roof intersects a vertical sidewall.” Read it twice. The second sentence describes a kick-out precisely — the eave, the vertical sidewall, the diversion — without naming the part, setting a length, or stating an angle. Text read in the Kentucky Residential Code Chapter 9 on October 4, 2026.

What is the difference between that and a code that names the part?

A named requirement is prescriptive and arguable; a functional requirement is not. Some states amended the same IRC to add a section that uses the words.

Minnesota, working from the same 2015 IRC, added section R903.2.2 titled Kick-Out Flashing/Diverter: “A kick-out flashing shall be installed where the lower portion of a sloped roof steps within the plane of an intersecting wall cladding, in such a manner as to divert or kick out water away from the assembly.” Kentucky did not add that section. The comparison is mine, drawn from the two states’ adopted texts, and the point is not that Kentucky’s rule is weaker — a functional requirement is harder to wriggle out of, not easier. The point is that an inspector in Kentucky is checking whether water is diverted, not whether a part with a particular name is present.

How does the sidewall flashing section interact with it?

It sets the only dimensions in the detail. Base or step flashing against a vertical sidewall must be at least 4 inches high and 4 inches wide, and must direct water away from that wall.

Section R905.2.8.3 (Sidewall flashing) reads: “Base flashing against a vertical sidewall shall be continuous or step flashing and shall be not less than 4 inches (102 mm) in height and 4 inches (102 mm) in width and shall direct water away from the vertical sidewall onto the roof or into the gutter.” So Kentucky’s code gives you two independent diversion duties at the same intersection: step flashing that pushes water out of the wall plane the whole way up the slope, and a flashing at the bottom of that run that keeps the collected water from running straight into the cladding at the eave.

Section	What it requires	Dimension stated
R903.2.1	A flashing that diverts water away where a sloped roof’s eave meets a vertical sidewall	None
R905.2.8.3	Continuous or step base flashing against a vertical sidewall, directing water onto the roof or into the gutter	Not less than 4 in. high and 4 in. wide
R905.2.8.5	Drip edge at eaves and gables of shingle roofs	Adjacent pieces lapped at least 2 in.

Why does the missing detail show up as a wall problem, not a roof problem?

Because the water lands behind the cladding, not on the ceiling. The stain appears on a wall below the roof-wall intersection, often a storey down, and nothing on the roof looks wrong.

That is the whole diagnostic value of knowing this detail exists. A roof plane that sheds into a sidewall concentrates the runoff of the entire plane into a few inches of wall at the bottom of the step-flashing run. If nothing turns that stream outward, it goes behind the siding or brick, and from there into sheathing and framing, where it does its damage out of sight and over years. The symptom pattern — a wall stain or soft trim below a roof-to-wall junction, with a dry attic and sound shingles — points at the bottom of the step run before it points at anything else.

In our own work the useful habit is to look at this detail from the ground before going up: stand where the eave meets the wall, look at the last few inches of flashing at the bottom of the step run, and ask whether anything there turns water out and away from the cladding. That is a two-minute look, and it is general craft rather than a claim about any particular house — we describe method here and never a customer’s property or a job we have not performed.

Where this sits with the rest of the flashing work

It is the bottom end of a detail we already cover further up the slope. Valley and wall flashing repair covers the run itself, chimney flashing covers the other common vertical interruption, and the slope ladder in Kentucky’s code covers which covering the code permits on each plane.

Does Kentucky’s code require a kick-out when re-roofing an existing house?

The Kentucky text we read does not contain a re-roofing exception for this detail, because it does not contain a separately named kick-out section at all — the diversion requirement in R903.2.1 is general. Some other states added both the named section and an exception. Confirm the scope of your permit with the local building official, since Kentucky permitting and inspection is administered locally.

How long should the diverter be?

Kentucky’s code states no length for it. The only dimension in the sidewall detail is the 4-inch minimum height and width for base or step flashing in R905.2.8.3. Anyone quoting you a Kentucky code minimum length for a kick-out is quoting a different state’s amendment or a manufacturer’s instruction, not this code.

Which edition of the code applies in Kentucky right now?

815 KAR 7:125 makes the 2015 IRC the mandatory state residential code, with the Kentucky amendments in the 2018 Kentucky Residential Code superseding any conflicting 2015 provision. The regulation’s most recent amendment took effect December 3, 2024. Read the current regulation at the link above rather than relying on a summary.

Last updated: October 4, 2026

By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.

Central Roof Repair is owned by Marcos Gil, who also publishes marcosgilrealty.com and forsalelexingtonky.com. This is general information about Kentucky’s adopted residential code, current as of October 4, 2026 — not legal, engineering or code-official advice, and not a representation about any particular roof. Code editions and local amendments change; verify with your local building official and the Department of Housing, Buildings and Construction.