Hardwood Flooring in Burlingame

Burlingame Conditions That Affect Solid Hardwood

Derived statistic, not a published normal: averaging NOAA Local Climatological Data hourly observations at San Francisco International Airport across the ten Julys 2015-2024 (Local Standard Time) gives 83.5% relative humidity at 04:00 (n=690) and 61.3% at 16:00 (n=627) — a daily swing of about 22 points. NOAA's published table gives Sacramento a July afternoon mean of 29%.

San Francisco International Airport records 1991-2020 January normals of 58.0°F average high and 44.5°F average low, with an annual precipitation normal of 19.6 inches. Winter runs the same cycle in reverse. Solid hardwood is a hygroscopic material: it moves with the seasons for its whole service life, and an install that ignores that is an install that telegraphs every season change through the floor.

Burlingame sits on the bay side of the northern peninsula. San Francisco International Airport normals at a July high of 72.6°F — between San Francisco Downtown at 66.3°F and Redwood City at 81.0°F further south. Whatever the outdoor pattern in Burlingame, solid hardwood responds to the air inside the house, so the wood acclimates to the rooms it is going into rather than to a delivery truck or a garage.

Measured Humidity and Solid Wood Movement in Burlingame

San Francisco International Airport, 2 miles from Burlingame and at about the same elevation, supplied the 80,024 hourly dewpoint readings, 2015 to 2025, behind these figures. Warm that winter air to 70°F without adding moisture and it settles at a median 42.3% relative humidity, with 11% of heating-season hours below the 30% floor NWFA sets for wood floors; the same air reaches 54.8% in summer. Solid hardwood follows those numbers: its equilibrium moisture content runs from about 8% in the heating season to 10% in summer, and on the Forest Products Laboratory's coefficients for American white oak that swing changes the width of a 5-inch plainsawn board by about 0.038 inch (about 1/27 inch) — against 0.019 inch for the same board quartersawn. That is a mild climate for solid wood, and it is why wider plank is a realistic choice in Burlingame rather than a gamble.

Source: Hourly ASOS dewpoint observations 2015–2025, Iowa Environmental Mesonet (Iowa State University); equilibrium moisture content from USDA Wood Handbook FPL-GTR-190 Eq. 4-5; movement from FPL-GTR-282 Eq. 13-3 and Table 13-5

Subfloor and Foundation Work

Burlingame's ZIP 94010 appears on CRMP's 2025 Earthquake Brace + Bolt eligibility list. The California Residential Mitigation Program states that 'an EBB seismic retrofit is only done on wood-framed, pre-1980 homes with a raised foundation,' targeting cripple walls in crawl spaces beneath the structure. 29.6% of Burlingame's 13,798 housing units were built in 1939 or earlier and 79.3% predate 1980. Even so, EBB ZIP eligibility is set on seismic hazard and housing age rather than foundation type, and no measured raised-versus-slab share for Burlingame was found, so the age figures indicate likelihood rather than proportion and no share is claimed.

Over a crawlspace, solid hardwood is in its element — plank or plywood subfloors take fasteners well — but only when the crawlspace itself is dry. We check the ground cover, look for standing water and rot at the joist ends, and read the moisture content of the subfloor from below. Cupping in a solid floor is almost always a crawlspace problem that surfaced upstairs.

Source: NAHB analysis of the Census Bureau Survey of Construction, foundation type by region (2024)

Burlingame Homes We Work In

ACS 2020-2024 five-year estimates count 13,798 housing units, of which 29.6% (4,086 units) were built in 1939 or earlier. A further 11.3% date to the 1940s, 13.6% to the 1950s and 12.9% to the 1960s. Only 10.4% was built in 2000 or later. Burlingame's pre-1940 stock is directly relevant here, because homes of that period frequently have a board or plywood subfloor that will hold a nail-down installation, and sometimes original wood still under the carpet. We check for both before quoting a full replacement — refinishing what's already there is often the better answer.