Floor Refinishing in Palo Alto

Palo Alto Conditions That Affect Floor Refinishing

Derived statistic, not a published normal: averaging NOAA Local Climatological Data hourly observations at Palo Alto Airport across the ten Julys 2015-2024 (Local Standard Time) gives 86.6% relative humidity at 05:00 (n=250) and 62.7% at 16:00 (n=235). The station reports only between about 05:00 and 19:00, so no overnight figure exists for it. For contrast, NOAA's Comparative Climatic Data table gives Sacramento a July afternoon mean of 29%. Palo Alto summers near 79°F change the finishing schedule more than the sanding. Waterborne finishes flash off faster in hot, dry air, which shortens the working window and makes lap marks easier to leave behind; we adjust application pace and airflow to the conditions in the house that day rather than to a fixed timetable.

NOAA 1991-2020 normals at the Palo Alto station give January an average high of 57.8°F and an average low of 39.0°F; December's 38.6°F is the coldest average low. Annual precipitation normal is 15.12 inches, with February the wettest month at 3.18 inches. Cold, damp conditions do the reverse and stretch cure times, which mostly costs patience — a floor that is walkable is not yet a floor that is ready for furniture or rugs.

Palo Alto's July normal high of 79.4°F runs about 13°F above San Francisco Downtown (66.3°F) and just below San Jose's airport station (80.8°F). Cool, damp days in Palo Alto lengthen finish cure times compared with a hot, dry one — a scheduling factor rather than a quality one.

Seasonal Gaps in Palo Alto Floors, by the Numbers

Seasonal gaps between boards are a common reason people ask about refinishing, and Palo Alto's measured climate shows how much of that gapping is simply the wood moving with the seasons. Measured at Moffett Federal Airfield, then brought to 70°F, the air averages 40.1% relative humidity over the heating season and 61.2% over summer, which settles wood at roughly 7.7% and 11.2% moisture content. For a traditional 2¼-inch oak strip floor that is about 0.030 inch of seasonal shrinkage per board (about 1/34 inch); for 5-inch plank, about 0.066 inch. Gaps in that range that open in winter and close by summer should not be filled — filler packed into a winter gap gets crushed out, or pushes the boards toward cupping, once the wood takes its moisture back.

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

What's Under the Finish

The city's adopted Eichler Neighborhood Design Guidelines (April 2, 2018) state that of the more than 11,000 homes Joseph Eichler built, 'some 2,700 were located in Palo Alto' — elsewhere the same document says 'well over 2,000' — across 31 tracts built between 1949 and 1974. As typical characteristics, the guidelines describe a 'post and beam construction method, built on a concrete slab foundation,' with 'Radiant heating is embedded in the concrete slab flooring,' and warn that the original radiant heating system 'may be difficult to repair without highly invasive intervention.' 70.0% of Palo Alto housing predates 1980. CRMP's 2025 Earthquake Brace + Bolt list, with eligibility 'based on ZIP Code only,' includes 94301, 94303, 94304 and 94306, ZIPs that contain Palo Alto addresses, for a program limited to 'wood-framed, pre-1980 homes with a raised foundation.'

Raised floors are where the best refinishing candidates live: solid wood over a crawlspace, often with decades of wear and plenty of thickness left. It is also where cupping comes from. Sanding a cupped floor flat before the crawlspace moisture is fixed produces a floor that goes concave the other way once it dries — so the moisture reading comes first and the sanding comes second.

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

Palo Alto Homes We Work In

ACS 2020-2024 five-year estimates count 29,241 housing units, with a median year built of 1963. The 1950s alone account for 25.1% (7,341 units), the largest single decade. 13.3% were built in 1939 or earlier and 12.1% in the 1960s. 58.9% of the stock predates 1970. Palo Alto's 1950s, pre-1940, and 1960s stock is where refinishing pays off most: homes of that period often have original wood under carpet, and when the wear layer is intact, refinishing keeps a floor that cannot be bought new. We check thickness at a vent or a doorway before recommending it.