A redeck means replacing, or covering over, the wood layer that sits under your shingles so the new roof is installed on a solid, flat surface. It is one of the most common reasons a roof job grows beyond "tear off and shingle", because the deck cannot be fully judged until the old roof is removed.
What is the roof deck?
The deck (also called sheathing) is the wood layer nailed to the rafters. The underlayment goes on top of it, and the shingles go on top of that. Nothing you can see from the ground is the deck, which is why a roofer can only estimate its condition before tear-off.
On many older homes the deck is made of spaced boards, with gaps between them, instead of solid sheets. That was a common way to build when the original roof covering was wood shakes, which need airflow to dry out. Newer homes are usually built with solid sheets of plywood or OSB.
When does a roof need a redeck?
A redeck is on the table when the surface under the shingles is not in shape to hold a new roof. Typical reasons:
- Boards or sheets that are rotted, soft or water-stained
- Spaced boards with gaps, when the new roof is meant to sit on a solid surface
- Old nail holes and fastener damage in large numbers
- Warped, cupped or uneven boards that would telegraph through new shingles
- Sections that were patched in different materials over the years
Our owner, Jeremy Hays, describes it plainly: when an old roof comes off, the deck can have hundreds of holes from years of nails, repairs and old fasteners. That is the kind of thing you cannot see from the driveway.
Replace the deck or cover it?
There are two common approaches. Which one is right depends on the condition of what is there and what the manufacturer's instructions call for.
| Approach | What it means | When it is commonly used |
|---|---|---|
| Replace damaged sections | Cut out bad boards or sheets and install new ones | Isolated rot or damage on an otherwise sound deck |
| Overlay the existing deck | Install new sheets over the old deck | Spaced or plank decking, or a deck that is sound but uneven |
| Full redeck | Remove and replace the whole deck | Widespread damage, or when the deck cannot support a new roof |
Our practice on a lot of older Oklahoma homes with spaced decking is to lay OSB sheets over the existing wood decking. That is how we do it, not a rule for every house, and a different house may call for a different answer.
Why a solid, flat deck matters
Shingle manufacturers publish installation instructions, and those generally assume the shingles are fastened to a sound deck that holds nails well. Gaps, soft spots and uneven surfaces can cause fastening problems and show through the finished roof as waves or low spots. We check the manufacturer's instructions for the product going on the roof.
How a redeck changes the estimate
An estimate before tear-off is a best reading of what the deck will look like. Many roofers include a line for decking repair or replacement, priced per sheet or per section, so that an unexpected finding does not stop the job. The number of sheets actually needed is known only after the old roof is off.
If a home is being replaced after a storm loss, the decking work can also touch how the policy reads. Read the policy and ask your agent, because policies differ.
How a redeck happens
- The old shingles and underlayment are removed down to the deck.
- The crew walks the deck and marks soft, rotted or damaged areas.
- Bad sections are removed, or the whole deck is overlaid, depending on the plan.
- New sheets are fastened to the rafters according to the manufacturer and code.
- The deck is checked for flatness and gaps before underlayment goes on.
- The homeowner is told what was found and what was done, ideally with photos.
Questions to ask your roofer
- How is decking priced, and what happens if more is needed than the estimate shows?
- Will you replace damaged sections, overlay the deck, or redeck the whole roof, and why?
- Can you show me photos of what you found after tear-off?
- What do the shingle manufacturer's instructions require for the deck?
- Who decides when a section is replaced versus left in place?
Frequently asked questions
Is a redeck the same as a roof replacement? No. A roof replacement removes and replaces the roof covering. A redeck is the work on the wood underneath, and it often happens as part of a replacement.
Can I tell if my roof needs a redeck from the ground? Usually not. Sagging, water stains on ceilings and a spongy feel are warning signs, but the deck is only judged after tear-off. Do not walk on a roof to check it.
Does OSB over old plank decking work? It is common practice on many older Oklahoma homes, and it is how our crews handle spaced decking. The right choice depends on the deck, so ask your roofer to explain the plan for your house.
Will the price change after tear-off? It can. Decking is one of the hidden items that can change a scope, which is why the estimate should say how decking is handled.
Is decking damage covered by insurance? That depends entirely on your policy and the cause of loss. Read your policy and ask your agent.
Talk to us about your roof
Total Roof Protection OKC can inspect your roof and explain what we see. Call 405-415-5841 to schedule an inspection. An inspection tells you about the roof. It does not predict or replace your insurer's decision.