Crawlspace Insulation — Assessment, Air Sealing & Install

Warmer floors, lower bills, drier structure. We upgrade crawlspaces the right way: fix moisture and air leaks first, then add code-level insulation that stays put and actually performs. Start with an on-site assessment; we’ll measure, photograph, and build a clear plan.

What we install

• Floor insulation: R-19 to R-30 fiberglass or mineral wool fit tight to the subfloor, kraft face to the warm side, supported with straps/twine—no sagging.
• Rim-joist air sealing: foam and mastic to block outside air at the perimeter.
• Vapor control: 6–12 mil ground vapor barrier (sealed seams, taped to piers/edges) to cut soil moisture.
• Encapsulation (when needed): sealed liner on ground and walls, foam-sealed penetrations, dehumidifier with drain for high-humidity sites.
• Details that matter: pipe and duct insulation, rodent-resistant screens at vents, combustion-safety clearances where gas equipment is present.

Why it works

• Comfort: warmer floors and fewer drafts in winter; less humid air in summer.
• Efficiency: HVAC runs shorter and quieter with tighter, drier cavities.
• Durability: reduced condensation, mold risk, and wood decay; protects ducts and plumbing.

Our process

• On-site assessment — check moisture (soil, plumbing, drainage), ventilation, existing R-value, rim-joists, ducts, and access.
• Scope & plan after the visit — floor R-value, vapor barrier or full encapsulation, air-sealing map, repairs (sill/rim, ducts, pipes).
• Prep — fix obvious leaks, grade/spot-level as needed, clean pathways, treat minor surface mold if specified.
• Install — air-seal rim and penetrations, set vapor barrier tight and sealed, fit insulation snug to subfloor with continuous support, insulate pipes/ducts.
• Handoff — photos, measured R-values, humidity/vent notes, and simple care tips.

Signs you need an upgrade

Cold floors • Musty odors • Visible sagging batts • Condensation on ducts/pipes • High winter bills • Rodent-disturbed insulation • Damp soil without a ground liner.

Wondering If We Cover Your City?

Our services are just as easy to schedule across multiple parts of the Bay Area. In the South Bay, we serve San Jose, Sunnyvale, Los Gatos, Saratoga, Campbell, Cambrian Park, Cupertino, Mountain View, Los Altos, Palo Alto, and Menlo Park.

On the Peninsula and the West Bay, we provide the same convenient support in Atherton, Redwood City, San Carlos, Belmont, Foster City, and surrounding areas. In the East Bay, we’re available in Fremont, Newark, Milpitas, and Union City—so wherever you are in our service area, help is close by and simple to book.

If you’re not sure whether we cover your neighborhood, just reach out—give us a call or submit a request online. It’s quick, easy, and completely free, and we’ll confirm availability and next steps right away.

Schedule an on-site crawlspace assessment and installation plan: 510-400-6425.