How do roofers handle dry rot and spaced sheathing on the East Bay reroofs?

What is roof decking, and what is dry rot?

Sheathing is the structural layer under the roofing: plywood or OSB on most newer homes, boards on many older ones. Rot sets in when wood stays wet long enough for fungi to break it down. Spaced (skip) sheathing is gapped boards, which suited ventilated shake roofs.

What does the code require under a new roof?

Under CRC R905.2.1, asphalt shingles must be fastened to wood structural panels or solid lumber sheathing. Spaced boards get covered or replaced, and rotted wood must go, because new roofing can't be fastened securely to it.

What are the signs of decking problems before tear-off?

• A wavy or sagging roofline
• Water stains in the attic or on ceilings
• Moss or debris that has sat for years
• Old leaks that were patched more than once

How is decking priced in a contract?

Ask every bidder to state a unit price for replacement decking, per sheet or per square foot, and to show you photos of what they replace. California requires extra work and change orders on a home improvement contract to be in writing (B&P 7159.6). For your actual price, request a free written estimate: a licensed roofer measures the roof and prices your exact scope.

Where does decking rot show up in the East Bay?

Pre-war Oakland and Berkeley homes are where East Bay roofers most often find board sheathing, sometimes spaced, under one or two old layers. Rot clusters around brick chimneys, at valleys and under trees in the hills, where leaves and needles hold moisture. Inland Contra Costa and Tri-Valley tract roofs are usually plywood or OSB over a simpler roof, and rot there tends to follow a specific old leak, a skylight or a failed vent boot rather than the whole deck.

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