Floor Installation in Mill Valley

Subfloor and Foundation Work

The City's Single-Family Residential Design Guidelines direct that buildings on sloped lots be designed to relate to existing landforms — 'for example, step with the slope' — and minimize earthwork cut, fill, and offhaul. Single-plane retaining or foundation walls visible from a public right-of-way are capped at six feet, with stepped retaining walls required above that height.

Regionally, crawl space use in Pacific-division construction has declined long-term and dropped sharply only in the past decade, against 89.9% slab in new 2024 builds — so raised floors turn up more often in Mill Valley's Pre-1940, 1940s, 1950s, and 1960s stock than in anything recent. We confirm on site.

A raised floor opens the material list back up — a sound wood subfloor accepts nail-down, glue-down, and floating installations alike. The condition of the crawlspace is what we check first, since a moisture problem underneath will eventually reach whatever we put on top.

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

Mill Valley Homes We Work In

ACS 2020-2024 5-year estimates show 28.2% of Mill Valley's 6,418 housing units predate 1940 — the oldest stock among the Marin markets covered here — with a further 11.5% built in the 1940s, 13.7% in the 1950s, and 16.6% in the 1960s. Roughly seven in ten units predate 1970. Mill Valley's Pre-1940, 1940s, 1950s, and 1960s homes tend to bring their own surprises once the old floor comes up — subfloor thickness, previous patches, and height differences at doorways. We plan transitions and thresholds around what's actually under there rather than around a nominal drawing.