Dry Rot Repair Cost in the Bay Area: What to Expect in 2026
If you just found soft wood under a window or got a pest report with "fungus/dryrot" circled, here's the short version: most dry rot repairs in the U.S. cost between $500 and $3,000, and the average job comes in around $1,400 (Angi). In the Bay Area, plan on 30 to 50 percent more than that.
So a rotted window sill or a section of fascia usually lands in the $500 to $3,000 range here. Once rot gets into studs, floor joists or the mudsill, the bill can climb past $10,000.
The biggest reason is labor. Carpenters in the San Francisco, Oakland and Fremont metro earn a median of $89,200 a year, about 47% more than the national median of $60,580, according to BLS wage data from May 2025. Dry rot work is mostly labor, so that gap shows up directly in your quote.
Below we break down what different repairs cost, why prices run higher here, and how to keep a small repair from turning into a big one.
Dry rot repair cost at a glance
Here's how the cost of dry rot repair breaks down by type of job. The national numbers come from Angi's 2026 cost data. The Bay Area column is our working estimate after adding the local labor premium.
Type of repair | National typical cost | Bay Area typical cost (estimate) |
Epoxy fill on a small soft spot | $150 to $250 | $250 to $500 |
Replace a rotted board, window sill, trim piece or fascia section | $300 to $2,000 | $500 to $3,000 |
Sister or replace structural framing (studs, joists) | $1,000 to $4,000 | $1,500 to $6,000+ |
General repair work, per square foot of damage | $5 to $40 | $7 to $60 |
Foundation-level framing (mudsill, rim joist), per square foot | $30 to $40 | $45 to $60 |
Treat these as ballpark numbers for budgeting. Nobody can give you a real price on dry rot until they've probed the wood, and often not until a few boards come off.
Why dry rot repair costs more in the Bay Area
Labor is the big one, but it isn't the only thing pushing local prices up. Here's what else is going on.
Our houses are old
The median home in San Francisco was built in 1948, the third oldest of the 100 largest counties in the country, and about 44% of the city's homes went up before 1940 (San Francisco Chronicle, citing Census data). San Mateo County's median is 1966 and Alameda's is 1969. The national median is 1981.
Older homes mean more surprises when the wall opens up. Original flashing is often worn out or missing, trim profiles on Victorians and Edwardians usually have to be custom milled to match, and decades of paint layers hide how bad the wood really is. That all adds time.
Lead paint rules add steps
If your home was built before 1978, it likely has lead paint somewhere. Under the EPA's Renovation, Repair and Painting rule, any contractor who disturbs more than 6 square feet of painted surface inside or 20 square feet outside has to be Lead-Safe Certified and follow containment and cleanup practices (Checkbook). A rotted window frame and the siding around it can hit that 20 square foot line fast.
The good news is it usually doesn't add much. Checkbook found most contractors don't charge extra for lead-safe work, and the ones that do typically add $100 to $200 on larger jobs. Just make sure whoever you hire is certified.
Permits depend on the scope
In San Francisco, the Department of Building Inspection lists in-kind dry rot and termite repair, along with deck and stair repairs under 50%, as over-the-counter permits that don't need plans (SF DBI). Deck or stair work over 50% and foundation repairs need drawings.
In plain terms: swapping a rotted board for the same thing is usually a quick permit. Replacing structural framing or anything at the foundation is a bigger process, sometimes with an engineer involved. Marin and San Mateo County cities each have their own rules, so check with your local building department or ask your contractor.
Weather keeps the wood wet
Fog belt neighborhoods stay damp for weeks at a time in summer, and winter storms drive rain sideways into siding joints and window trim. Wood that never fully dries out is exactly what rot fungi need.
What drives the price of a dry rot repair
Two jobs that look the same from the outside can be thousands of dollars apart. These are the things that make the difference.
How far it spread
This matters more than anything else. Small areas cost more per square foot, but bigger areas cost more overall. National figures from Angi:
Damaged area | National typical cost |
10 sq ft | $150 to $400 |
25 sq ft | $200 to $1,500 |
100 sq ft | $500 to $3,000 |
500 sq ft | $1,000 to $10,000 |
Where it is in the house
Trim around a first floor window is easy to get to. A beam in a tight crawl space or fascia on a third story is not. Angi puts wall and window framing at $5 to $25 per square foot, roof and floor structure at $10 to $40, and foundation-level wood at $30 to $40. On a steep San Francisco lot, add scaffolding or extra ladder setup to that.
What has to come off and go back on
Getting to rot usually means pulling siding, drywall, trim or decking, and all of it has to be put back and painted. Angi lists drywall repair at $295 to $925, new trim at $635 to $2,245, and painting a room at $400 to $1,600. These add-ons can cost as much as the rot repair itself.
Fixing where the water comes from
Dry rot is a water problem first. If a failed gutter, missing flashing, a leaky downspout or a sprinkler hitting the siding caused it, that has to get fixed in the same job. Skip it and you'll be paying for the same repair again in a few years.
What is dry rot, and what causes it?
Dry rot is wood decay caused by fungi, and despite the name, it needs moisture to start. The "dry" part describes what the wood looks like afterward: brown, cracked into little cubes, and crumbly enough to break apart in your fingers.
The usual cause is simple. Wood stays wet long enough for fungus to take hold, typically from a slow leak, bad flashing, failed caulk, poor drainage or soil touching the framing. Fix the moisture and the fungus stops spreading.
The California exception: poria
There's one fungus Bay Area homeowners should know by name. Meruliporia incrassata, usually called poria, grows root-like strands that can carry water up to about 25 feet from its source, so it can rot wood that looks like it should be dry (background on poria). It often pulls that water straight up from the soil, and poorly ventilated crawl spaces are especially at risk.
A researcher at UC's Forest Products Laboratory reported finding poria in homes in Oakland, Fremont, Belvedere, Pleasant Hill and Santa Cruz, among other places (Puget Sound Mycological Society bulletin). Repairs for poria work differently. Every one of those water-carrying strands has to be found and cut, or the rot keeps coming back (Journal of Light Construction). That extra detective work can push a job toward the high end of the ranges above.
What does dry rot look like?
You don't need special tools to check for dry rot in your house. Grab a flashlight and a flat screwdriver and walk the outside of your home. Here's what to look for:
Soft wood. Press the screwdriver into window sills, door jambs, fascia boards and deck posts. Healthy wood pushes back. Rotted wood lets the tip sink in.
Brown, cracked wood. Dry rot breaks wood into small cube-shaped chunks that crumble when you press them.
Paint failing in one spot. A bubble or peel in one area, especially below a window corner, often means moisture is coming from behind.
A musty smell. Damp, earthy smells near windows, closets on outside walls, or under the house are worth a closer look.
White strands or mushroom-like growth. If you see fungus growing on wood, the rot has been active for a while.
Sticking doors or windows, or a spongy floor near an outside wall. These can mean the rot has reached framing.
The usual trouble spots in Bay Area homes are window sills and trim, door thresholds, fascia behind gutters, deck ledgers and stair stringers, bay window bases, and siding near downspouts.
Dry rot vs termite damage, and what your Section 1 report means
Dry rot and termite damage can look alike at first, but they're different problems. Rot leaves brown, cracked, crumbly wood and points to a moisture issue. Termites hollow out wood along the grain and leave mud tubes or small pellets behind. Rot needs a carpenter and a moisture fix. Termites need a pest control company, and often a carpenter too.
If you're buying or selling a home in California, you'll probably see both on a Wood Destroying Pests and Organisms Inspection Report. These reports are governed by the state's Structural Pest Control Act, and "Fungus/Dryrot" is one of the standard categories (sample report). Findings are split two ways:
Section 1 items are active infestation or infection, or damage that's already there. This is the work buyers and lenders usually want done before closing.
Section 2 items are conditions likely to lead to rot or termites, but with no visible damage yet. Think a leaky faucet, wood touching soil, or bad drainage.
Pest companies usually put a price on each item in the report, but you're not required to use them for the carpentry. Getting a second bid from a licensed general contractor for the wood repair is common, especially on bigger Section 1 items like framing or deck structure. Just ask the pest company what they charge to come back out and reinspect, since you'll want their sign-off once the work is done.
Will insurance cover it?
Usually not. Standard homeowners policies treat dry rot as gradual damage from long-term moisture or deferred maintenance, so it's generally excluded (Angi). The exception is rot caused by a sudden, covered event like a burst pipe or storm damage. Even then, the policy may pay for the water damage and not the rot that followed. Call your insurer before you assume either way.
Can you just patch it with epoxy?
Sometimes. For shallow surface rot on trim or a sill that's still solid underneath, a two-part epoxy fill is a legitimate fix and can cost as little as $150 nationally (Angi).
Epoxy doesn't restore strength, though. If the rot is deep, or it's in anything carrying weight like a stud, joist, beam or deck post, the bad wood has to come out and be replaced or sistered with new lumber. Filling soft wood without cutting it back first just hides the problem until it shows up again, usually bigger.
How to keep the bill down
The cheapest dry rot repair is the one you catch early. Angi notes rot can cause visible damage within a month and structural damage if left alone for six months to a year. A few other things help:
Fix the water first. Gutters, flashing, caulk and drainage are cheap compared to framing. Ask that the moisture source be part of the written scope.
Check every fall. Before the rains start, walk the house with a screwdriver and look at sills, fascia, thresholds and deck connections.
Bundle the work. If you're planning to paint, do the rot repair right before. You pay for one setup, one round of ladders or scaffolding, and one paint job.
Get a written scope with a contingency. Nobody can see inside a wall. A good quote says what happens, and roughly what it costs, if the rot goes further than expected. Setting aside 10 to 20 percent extra is a safe habit.
Don't let a pest report sit. Section 2 conditions are cheap to fix now and turn into Section 1 repairs later.
Working with a dry rot repair contractor in San Francisco, Marin and San Mateo
Pillar to Pillar Construction is a licensed California general contractor (CSLB #1137809) that handles structural repairs and dry rot build-backs across San Francisco, Marin County and San Mateo County. Owner Jerry Lyons walks every property himself, so the person who looks at your rot is the same person running the repair.
Here's how we approach a dry rot job:
Find the water. We track down where the moisture is coming from before we price anything.
Probe and open up. We check how far the rot goes and show you what we find, with photos.
Cut back to sound wood. Rotted material comes out. Structural pieces get replaced or sistered, not filled.
Fix the source. Flashing, caulk, drainage or whatever let the water in gets corrected in the same job.
Close it up to match. Siding, trim and paint go back so the repair blends in.
We also rebuild rotted decks and stairs as part of our custom outdoor structures work.
Got soft wood, a pest report, or just a bad feeling about a window sill? Call Jerry at (415) 310-7678 or email jerry@pillartopillar.com for a free estimate. We're licensed, bonded and insured.
Dry rot repair FAQ
How much does dry rot repair cost in San Francisco?
Small repairs like a window sill, trim board or fascia section typically run $500 to $3,000 in San Francisco. Repairs that reach studs, joists or the mudsill often cost $1,500 to $6,000 or more, and large areas can pass $10,000. Prices run 30 to 50 percent above national averages, mostly because of local labor costs.
How fast does dry rot spread?
Once wood stays wet, rot can cause visible damage within about a month. Left alone for six months to a year, it can weaken structural wood. How fast depends on how wet the wood stays.
Do I need a permit to repair dry rot in San Francisco?
Often yes, but it's usually simple. SF DBI lists in-kind dry rot and termite repair as an over-the-counter permit with no plans needed. Structural or foundation work, or deck repairs over 50%, need drawings. Other Bay Area cities set their own rules.
Is dry rot covered by homeowners insurance?
Generally no. Insurers treat it as gradual damage. If the rot came from a sudden covered event like a burst pipe, part of the repair may be covered. Check your policy.
Should I call a pest company or a contractor?
For a home sale, a licensed pest company writes the inspection report. For the repair itself, a licensed general contractor can do the carpentry, and it's worth getting their bid on larger jobs. If termites are involved, you'll need the pest company for treatment either way.
Is dry rot dangerous?
For most people it isn't a direct health risk, though damp conditions can bother anyone with breathing issues. The real danger is structural: rot in joists, posts or deck ledgers weakens what's holding things up. See our structural repair services if you think it's reached framing.
