Whole-home roofing for older homes renews every layer of the roof, from the covering to the sheathing, because earlier work is often unrecorded. The tear-off tells you what is there, and the scope has to anticipate what it might find.
Planning for layers nobody wrote down
On a house with a long record of work, nobody may know how many layers are on the roof or what is under them. The tear-off answers that, so the scope names how it will respond: replace soft boards, remove stray fasteners, and clear old flashing before new underlayment goes down.
Where County rules apply, a second layer is allowed only over a single existing layer and a sound deck (LA County Public Works, BCM 1512, 1 Apr 2025).
Solid sheathing and spaced boards
Some older roofs use spaced boards with gaps between them. New roofing generally wants a solid surface to nail into, so the gaps are closed with plywood.
The code also treats spaced sheathing differently. A radiant barrier counts as a cool roof exception only when it is not installed over spaced sheathing (California Energy Commission, 2022 Standards).
What a whole-home renewal includes
- Complete tear-off, with layers counted and recorded
- Soft or cracked sheathing replaced, spaced boards closed
- Ventilation checked and corrected where needed
- New underlayment and flashing throughout
- A covering chosen for the house and its district
- The permit and inspection for the address
Signs an older roof needs a full renewal
- Layers stacked at the eave edge
- Sagging between rafters or a springy deck
- Attic moisture or stained rafters
- Flashing sealed over with layers of mastic
Ventilation and the attic
A roof and its attic work together. Intake at the eaves and exhaust near the ridge let moisture and heat escape, and the reroof is a good moment to see whether they still do. Obstructed soffit vents or an undersized exhaust can shorten the life of the new underlayment.
The scope notes what is found and what is changed.
Paperwork an older roof can bring
Older roofs may contain materials that need testing before removal; ask your roofer.
Carriers matter as well. Insurance Business America reported on 26 May 2026 that some carriers limit coverage on roofs over 25 years old.
Questions about older roofs
Why close in spaced sheathing with plywood?
New roofing needs a solid, even surface to fasten to, and gaps leave nothing for nails to hold. Plywood supplies that surface. It also changes the cool roof picture, since the radiant barrier exception does not apply over spaced sheathing.
Is a reroof the moment to upgrade attic ventilation?
It is the moment to check it, and to correct intake or exhaust that is obstructed or too small. Moisture and heat in the attic shorten the life of underlayment, so ventilation belongs in the scope.
Does old roofing need a test?
Older roofs may contain materials that need testing before removal; ask your roofer. Doing it first lets you plan the removal with the answer in hand.
Should the scope for an older roof be in writing?
Yes. A written scope by layer shows what comes off and what goes on, and it is the document to compare between bids.
Does an older roof change insurance on an older house?
It can. Insurance Business America reported on 26 May 2026 that some insurers, Mercury and Wawanesa among them, generally decline homes with roofs past 25 years, tile and slate excepted. Ask your own insurer what applies.