Is two layers of shingles bad on a roof?

Is two layers of shingles bad?

Two layers wear out sooner and void the shingle warranty, though they leak less. The home inspectors' trade group, the International Association of Certified Home Inspectors (InterNACHI), says "multiple layers get hotter and hold heat longer, so shingles won't last as long, although the roof is less likely to leak." Get a licensed roofer's written opinion on the years left and a bid to remove both layers, then build your ask on that bid.

Key takeaways

• A wood-shingle bottom layer can mean solid sheathing across the entire roof.
• Rotted decking found under the old roof is billed per sheet, on top of the tear-off.
• On a Federal Housing Administration (FHA) loan, the appraiser must report a roof with less than two years of life left.

How much does it cost to remove two layers of shingles?

More than one layer, because the crew hauls more weight and debris. A roofer in Downers Grove and Naperville, Illinois, Excellent Roofs, says the extra weight "means more labor, more time, and significantly more debris to haul away."

Here is the math on a 2,000-square-foot roof at SquareDash's rates, 2,000 times the per-foot figures in the table. Two layers come off for $2,500 to $3,500, against $2,000 to $2,500 for one. The second layer adds $500 to $1,000. Each rotted sheet the crew finds adds $75 to $100 on top. Two layers also take roughly 50% longer to tear off than one, which SquareDash puts at 4 to 6 hours on a 2,000-square-foot home.

Kept prices every line of an inspection report for $79, usually under 4 hours, and marks the ones that need a professional quote.

The Illinois roofer's one-layer rate runs up to $3 per square foot, so a local two-layer bid can land well above SquareDash's. Treat the table as a starting range, not your ask. Your ask is a licensed roofer's written bid at your roof's real layer count. If the roofer says the roof needs replacing now, the tear-off is only part of the price: the Illinois roofer puts a complete replacement at $5,700 to $12,000 for 3-tab shingles and $9,000 to $16,000 for dimensional ones. Check that the bid includes removing both layers. How to get repair estimates during the inspection period covers getting a roofer out fast.

Why does the house have two layers of shingles?

A past owner had new shingles laid over the old ones instead of tearing them off. InterNACHI tells inspectors they'll "often find newer shingles installed right over old roof-covering materials." That skipped a tear-off bill then. The next roof pays it.

The warranty goes with it. InterNACHI says "shingles installed over other shingles will also not have a valid manufacturer's warranty." If the seller lists a shingle warranty, ask for the paperwork. Ask for the permit and invoice from the overlay too, and show both to your roofer: the date tells them how old the top layer is.

How long will a second layer of shingles last?

Not as long as a single layer of the same shingles, because the extra heat ages them faster. The number of years that counts is your roofer's.

Ask the roofer for two things in writing: how many years the top layer has left, and whether the roof needs replacing now. If the report also notes a ceiling stain or active leak, get the roofer out first.

Ask what's under the top layer, too. InterNACHI notes that asphalt shingles over wood shingles have lower impact resistance, because the uneven wood leaves more gaps underneath.

Can you sell a house with two layers of shingles?

The seller is doing it now, so the real question is your loan. On an FHA loan, the Department of Housing and Urban Development (HUD) Handbook 4000.1 says "the Appraiser must report if the roof has less than two years of remaining life." If you're using an FHA 203(k) rehab loan, HUD's 203(k) Consultant 35 Point Checklist in the same Handbook 4000.1 adds: "Roofs that already have two layers of shingles should not be roofed again." On any other loan, ask your loan officer what the appraisal checks on the roof.

Can you put a new roof over two layers of shingles?

Your local code decides. San Bernardino County, California's building department, for example, bars a new layer "where the existing roof has two or more applications of any type of roof covering." InterNACHI's flashing guide tells inspectors that where the limit is two layers, "all roofing materials will have to be removed" before re-roofing.

If your area has that rule, the next roof on this house starts with a full tear-off down to the deck. Your local building department answers for your address.

A wood-shingle bottom layer makes that job bigger. In InterNACHI's example of asphalt over wood shingles, the roof would need solid sheathing installed across the entire roof.

What should I ask the seller for?

It depends on what the roofer tells you.

• The roof needs replacing now: ask for the replacement at the roofer's full written bid, not the tear-off figure, with both layers removed, as a repair or a credit.
• The roof has years left: the second layer is a cost you'll pay at the next roof. Ask for the extra tear-off as a credit, or fold it into a price cut.
• The roof has a leak: ask for the repair the roofer names, and the tear-off question waits.

Write the line so the seller can't misread the scope. If the roofer says the roof needs replacing now:

Roof: two layers of asphalt shingles noted in the inspection report. Remove both layers to the deck and replace, per the attached licensed roofer's written bid.

If the roofer says the roof has years left:

Roof: two layers of asphalt shingles noted in the inspection report. Credit of the extra tear-off cost for the second layer, per the attached licensed roofer's written estimate of the roof's remaining life.

What to ask for after a home inspection covers how this line fits your list. The buyer repair request letter template gives you the wording around it.

What if the seller says no?

You choose between the deal as written and the roof you'll pay to replace. A roof with a written bid is a known cost, so you can weigh it against the price. When to walk away after a home inspection lays out that call.

Your contract sets the deadline to respond and whether you can cancel, so confirm the date with your agent. For the other roof lines inspectors flag, see roof findings on an inspection report.

How do I know what the rest of my report is worth?

Your roofer prices the roof. Kept prices the other lines and marks the ones that need a professional quote, so your roofer's visit goes to the line that needs it.

If the roof is one finding among many and your deadline is close, upload your inspection report to Kept and have numbers for the rest of your list while the roofer writes the bid.

Sources

• InterNACHI, Mastering Roof Inspections: Asphalt Composition Shingles, Part 12
• InterNACHI, Mastering Roof Inspections: Asphalt Composition Shingles, Part 18
• San Bernardino County Building and Safety, Residential Reroof Asphalt Shingles
• HUD Handbook 4000.1, including the 203(k) Consultant 35 Point Checklist
• SquareDash, Tear Off and Replace Roof Cost
• Excellent Roofs, Cost to tear off and replace shingles