Sometimes. Installing new shingles directly over existing ones is called an overlay or layover, and it is allowed in some places under certain conditions. But allowed is not the same as a good idea, and our crews tear off the old roof on most replacements. Code and manufacturer rules both vary, so check them before you decide.
What is an overlay, and what is a tear-off?
In an overlay, the old shingles stay where they are and the new roof is nailed through them. In a tear-off, the old shingles and underlayment are stripped down to the wood deck, the deck is checked and repaired, and new material is installed from scratch.
| Overlay | Tear-off | |
|---|---|---|
| Old roof | Left in place | Removed |
| Deck inspected | No, hidden under the old layer | Yes, fully exposed |
| Weight on structure | Increases | Stays near the original design |
| Surface quality | Follows the old surface, bumps included | Flat, clean base |
| Labor and disposal | Less | More |
| Typical issues | Hidden rot, telegraphing, warranty questions | Higher up-front effort |
The overlay vs tear-off comparison walks through the trade-offs in more detail.
Why do many roofers insist on tear-off?
Our crews' view is that the deck is the foundation, and you do not know a foundation's condition by putting more weight on top of it. These are the reasons we give:
- You cannot see the deck. Rot, soft spots and failed nails stay hidden beneath an overlay.
- Old decks are often not ready for a new roof. Oklahoma has many older homes with spaced plank decking, and our owner has posted that it was the first place he encountered it. These decks usually need to be covered or replaced. See what is a redeck.
- Hidden damage shows up as holes. Our owner has posted about decks with hundreds of holes from years of fasteners once the roof comes off. An overlay never gives anyone the chance to see that.
- The old surface shows through. Curled edges and raised nail heads telegraph into the new shingles as waves.
- Old underlayment stays. The layer under the old shingles remains, along with whatever condition it is in. See what is underlayment.
- Weight adds up. Two roofs weigh more than one, and the structure has a limit.
- Fastening is harder. Nails need to pass through everything and still hold in the deck.
Is an overlay ever acceptable?
Under some codes, on some roofs, a single overlay may be permitted when the existing roof is flat and sound, the deck is solid and the manufacturer allows it. Some manufacturers limit or exclude warranty coverage on overlays, and some of their products are not intended for installation over existing roofing. That is why the shingle instructions come first. Check how many layers your roof already has, because there are limits. Our answer on how many layers of shingles are allowed explains why the answer depends on where you live. Requirements vary by city and county; ask your building department or roofer.
What does an overlay do to a hail-damaged roof?
If the old roof was hit by hail, the damaged shingles are still under the new ones. Bruises do not disappear. A tear-off lets the crew see what was there. If you are thinking about an overlay after a storm, ask what it means for any damage you have and for your policy, because policies differ.
What should I ask a roofer who suggests an overlay?
- Does the shingle manufacturer allow it, and does the warranty still apply?
- How many layers are on the roof now?
- What does the local code require for my address?
- How will you check the deck?
- What happens if you find rot or damage later?
Get the answers in writing.
Frequently asked questions
Is it cheaper to put shingles over old ones? It usually saves tear-off labor and disposal, but it can cost more later if hidden problems appear. Ask for both options in writing.
Does an overlay void my warranty? It can reduce or exclude coverage depending on the manufacturer. Read the warranty for your product.
Can I overlay metal panels over shingles? Some metal systems are designed for it, but the same hidden-deck concerns apply, and requirements vary. Ask the manufacturer and your building department.
Can I overlay over a roof with leaks? We would not. Leaks mean the deck may be damaged, and an overlay covers it up.
Do home buyers care if a roof was overlaid? Many do. An inspector may note layers. Ask your agent and a roofer.
Will insurance pay for a tear-off or an overlay? Policies differ. Read yours and ask your agent.
Talk to us about your roof
Total Roof Protection OKC can inspect your roof and explain which approach makes sense. Call 405-415-5841 to schedule an inspection. An inspection describes your roof and does not predict an insurer's decision.