Dry rot in a San Francisco house, termites, and the Section 1 report

It usually starts with a screwdriver. You press it into the corner of a window sill, or the bottom tread of the back stairs, and it sinks in as if the wood were cork. Or it starts with paper: a pest report with 'fungus damage' listed under Section 1 and an escrow deadline beside it. The questions are the same either way. What is it, how far does it go, and who fixes it?

#Dry rot isn't dry

Dry rot is decay by fungi that digest wood, and they can only do it when there's liquid water in the wood. University of California extension research puts that at a moisture content above about 28 percent (UC ANR). The fungus also needs oxygen, a mild temperature and the wood itself, and taking away any one of the four stops it. Air and temperature are hard to change in a house, so the fight is over water, and over treated wood where the wet won't go away.

Most rot in buildings is brown rot. It eats the cellulose and leaves the lignin, which is brown, so the wood darkens, shrinks and splits along and across the grain into small blocks. Wood scientists call that cubical checking. Dried out, it crumbles between your fingers, and that dry, crumbly look is what people mean by dry rot. Brown-rot fungi favor softwoods such as Douglas-fir, and UC's termite Pest Notes name Douglas-fir among the usual framing lumbers in buildings.

#Where rot starts on a San Francisco house

Rot starts where water arrives and can't leave. On the fog side of town a shaded north wall dries slowly, but the usual sources are plainer: a leak, a sprinkler, soil against the wall. Walk the outside first, then the garage and back stairs, then the bathrooms. The numbered spots are the kind California's report rules tell inspectors to cover.

#Dry rot or termites? How to tell

Inspectors tell them apart by the shape of the damage and what's left lying around it. The table is the field version. It won't replace a probe and a flashlight in the crawlspace, because termite damage can hide under a surface that still looks fine (SPCB).

Two more things. Termites prefer wood that decay has softened, so a report can list both on one board (UC IPM). And a swarm of winged termites out of a stump in the yard doesn't by itself mean the house is infested; swarmers coming out at the base of a foundation wall or a porch are another matter, the state's brochure says.

#A sample report, read line by line

What follows is a sample: an invented report on an invented 1920s house in the Outer Sunset, laid out the way California reports are. Wording differs by company, but the parts are fixed by Business and Professions Code 8516 and the Structural Pest Control Board's report rules, so you'll find every one of them in yours.

1. The header: who looked, and when

   The opening lines give the date the inspection started, the inspector's name, license number and signature, who ordered the report and who owns the house. The company has to deliver it within 10 business days of that start date, and before any work begins. Sample: 'Inspection started 9/14 by a Branch 3 field representative; ordered by the listing agent.'

2. Complete, limited, supplemental or reinspection

   The report says which kind it is. A limited report covers only the area it names, so a limited report on the back stairs tells you nothing about the bathroom floor. A supplemental report follows when a closed-up area is opened later. Sample: 'Complete report, separated.'

3. The diagram

   A sketch of the foundation and the structure, with numbers placed where the findings are. The law asks for damaged members to be named the way a builder would name them: siding, studs, rafters, floor joists, fascia, subfloor, sheathing, trim. Sample: item 3A drawn at the rear stairs, 1A at the back bedroom window.

4. The separated-report paragraph

   Just before the first finding, a separated report prints fixed language from the Board's regulation. Section I items show visible evidence of active infestation or infection, or of conditions that resulted from one; Section II items are conditions likely to lead to one, with no visible evidence yet. Sample: the paragraph, word for word, above item 1A.

5. Section 1 findings

   Sample 1A: 'Fungus damage at the sill and lower jamb, rear bedroom window. Remove and replace the damaged wood.' Sample 3A: 'Fungus damage to the rear stair stringers and the landing joists.' A clearance hangs on these. Correct them and the company can certify the house; leave them and the certification lists them as exceptions.

6. Section 2 findings

   Sample 2A: 'Earth-wood contact at the garage door jambs.' Sample 2B: 'Excessive moisture at the base of the front planter.' The law bars a company from calling these active infestations or defects, or from making them a condition of the certification. If you decide not to fix them, the company isn't liable for what follows.

7. Further inspection

   Places the inspector couldn't get to: a stall shower over a finished ceiling, a floor under carpet, a bay window closed in with finish work, a locked storeroom. The report must say what wasn't inspected and why. Some agents call these 'Section 3'; the regulation calls them further inspection items, and opening them up brings a supplemental report that can add new Section 1 or 2 items.

8. The roof sentence

   One of two bold sentences appears. Either the roof's outer surface was inspected for pests, or it wasn't, in which case the report tells you to ask a roofing contractor if you want to know whether it keeps water out. A pest report is not a roof inspection either way.

9. The second-opinion notice

   Every report prints a boldface notice: reports from different companies should list the same findings, but their recommendations may differ, and you have a right to a second opinion. Take that seriously when one company proposes rebuilding a stair and another proposes replacing two treads.

10. Bids and the reinspection clock

    Ask for each recommendation priced on its own line; a company that does that kind of work has to break it out on request. If it gave a bid, it must reinspect when asked, within 10 business days, for no more than its original inspection price. Four months after the original inspection, any new inspection counts as an original.

11. The certification

    The clearance is a short statement in set words: no evidence of active infestation or infection was found, or the property 'is now free of evidence of active infestation or infection,' and either way only 'in the visible and accessible areas.' Read that last phrase twice. It certifies what could be seen.

A clearance covers the visible and accessible areas. Whatever sits behind the plaster isn't in it.

#Section 1, Section 2, and who pays

Who pays is a contract question. None of the laws behind the report, B&P 8516, B&P 8519 or Civil Code 1099, assigns Section 1 or Section 2 work to the buyer or the seller. Section 1099 only makes the seller hand the buyer a copy before title transfers when the contract or the lender calls for a report. The rest is negotiated, so read the purchase contract before you sign. This is general information, not legal advice.

Wondering whether the house was inspected before you? The Board keeps a searchable record of properties inspected in the last two years, and you can request copies of those reports in writing. Selling? The selling guide covers San Francisco's own point-of-sale rules.

#Who can do the repair, and what gets the clearance

Whoever does the work, the clearance comes from the pest company. It certifies after its own notice of work completed, or after a reinspection shows every recommendation for the Section 1 items done (B&P 8519). So if a contractor is doing the repair, confirm first that the pest company bid the work, which is what obliges it to reinspect, and have the contractor follow the report's recommendation.

#What decides the size of a dry rot repair

Nobody can size a rot repair honestly until the wood is opened. These are the things that move it, roughly in the order they turn up:

• How far the decay runs. The soft spot you found is where it showed, not where it necessarily stops; nobody knows the extent until the wood is probed and opened.
• Whether it's structural. Trim and sills are carpentry. Joists, posts, stair stringers and the sill under a wall are framing, which can bring a permit and temporary support while members are replaced.
• What covers it. Rot behind stucco means cutting and patching stucco; behind shingles or lap siding it means matching a profile. Stucco and siding pros handle both.
• Where the water comes from. A gutter, a failed window flashing, a sprinkler, a planter. If it isn't fixed in the same job, the new wood starts the clock over; the rainy-season checklist covers gutters and drainage.
• Poria. With Meruliporia, the job reaches the detail that let it in: the grade, a planter, a foundation crack.
• Old paint. On a pre-1978 house, lead-safe setup and cleanup are part of the work, and the patch needs paint that sheds water.
• The window itself. When the sill is gone and the sash with it, repair turns into window replacement, with permit questions of its own.