Insulation Before & After in Sunnyvale, CA
Talk is cheap in this trade. You can read all the spec sheets you want, but nothing tells the story like walking into a Sunnyvale ranch house in mid-July and feeling the upstairs and downstairs read the same on the thermometer. Here’s a look at real projects, real problems, and what changed after we got into the attic, the walls, and the crawl space.
Recent Transformations
Attic Insulation Replacement in Sunnyvale’s Birdland Neighborhood
The problem: A 1960s track home still had its original fiberglass batts, compressed to about two inches in places and scattered with rodent droppings. Upstairs bedrooms ran 10 to 15 degrees warmer than the rest of the house all summer. What we did: Full removal, attic cleaning, rodent proofing, air sealing around the top plates, and fresh blown-in Johns Manville fiberglass to R-38. The result: The upstairs finally holds temperature. The homeowner called us back two weeks later and said the AC actually cycles off now, which it hadn’t done in the three summers they’d lived there.
Spray Foam Insulation for Attic Roof Deck in Cupertino Border Home
The problem: A newer two-story with a vaulted ceiling in the primary bedroom that had no real attic space. The HVAC ducts ran through an unconditioned attic, and the bedroom was the hottest room in the house. What we did: Icynene open-cell spray foam on the underside of the roof deck, converting the attic into a conditioned space. The result: The temperature difference between floors dropped from 12 degrees to under 3. The furnace no longer tries to heat a cold attic in January.
Crawl Space Encapsulation and Vapor Barrier in Heritage District
The problem: An older Craftsman-style home sat over a dirt floor crawl space. Musty smell in the living room, hardwood floors starting to cup, and a family member with worsening allergies. What we did: Crawl space encapsulation with a heavy vapor barrier up the foundation walls, sealed seams, and rim joist insulation. The result: Humidity in the crawl space dropped from 78% to 42% within a week. The smell was gone by the time the family unpacked from their weekend away. The floors settled back flat over the next month.
Wall Insulation Retrofit for 1950s Eichler-Style Home
The problem: An Eichler-style home near Ponderosa Park had zero wall insulation. Walls radiated heat by late afternoon, and the homeowners were running portable heaters in the bedrooms during winter. What we did: Drill-and-fill dense-pack GreenFiber cellulose from the exterior, color-matched plugs, and repaint touch-up. The result: Heating costs dropped noticeably that first winter, and the wall surfaces stopped feeling like radiators after 4pm. Nobody can tell we were in the walls until you look at the utility bill.
Radiant Barrier Installation with Attic Air Sealing in Sunnyvale West
The problem: A 1970s split-level with a sprawling attic surface area. The AC could not keep the main living area below 78 degrees on hot days, even after a new condenser unit. What we did: Attic air sealing around penetrations, then a radiant barrier stapled to the underside of the roof rafters. The result: Attic temperatures dropped from 140 degrees to around 105 on a 95-degree day. The living room holds at 74 without the unit running constantly. This is a straightforward fix most Sun
nyvale homeowners don’t know they need until we run the numbers with a thermal camera.
Attic Cleaning and Rodent Proofing Before New Insulation in Cherry Chase
The problem: A family in Cherry Chase kept hearing scratching above their daughter’s bedroom. When we got up there, the attic was a rat superhighway: tunnels through the old insulation, chewed wiring, droppings everywhere. What we did: Full removal of contaminated insulation, HEPA vacuum, sanitizing treatment, sealed entry points at every eave and vent, and new blown-in Rockwool insulation. The result: No more scratching. The wiring inspection passed. And the parents finally stopped worrying about what was living above their kid’s ceiling.
Want Results Like These?
Every house in Sunnyvale has different bones, a different history, and different headaches. We’ve been fixing them since 2000, and the Done Right Promise covers every job we do. Call Walt’s Insulation at (669) 215-4805 and talk to a live person about what’s going on in your house. Free second opinion on any written estimate, no trip charge in our county, and 10% off for seniors and veterans, always.
Written by Walt Brenner, Owner at Walt’s Insulation, serving Sunnyvale since 2000.