Insulation Before & After in Cupertino, CA
Photos don’t lie. A blown-in cellulose job looks like a blanket of gray snow when it’s done right, but the real story is underneath: the sealed top plates, the blocked chase, the airtight envelope that keeps Cupertino’s summer heat out and winter heat in. Here’s what that work actually looks like on homes we’ve completed in Cupertino.
Recent Transformations
Attic Insulation Removal & Replacement, Monta Vista
The homeowner in Monta Vista called after finding rat droppings throughout their original 1980s fiberglass batts. We removed the contaminated material, sealed every top plate gap and recessed can light with fire-rated foam and metal flashing, then blew in GreenFiber cellulose to R-38. The blower-door test read 3,800 CFM50 before sealing and 2,100 after. The written scope and photo record documented every sealed penetration before insulation covered it.
Crawl Space Encapsulation & Vapor Barrier, Rancho Rinconada
A Rancho Rinconada ranch built in 1964 had a dirt crawl space that smelled like mildew every winter. We installed a 20-mil reinforced vapor barrier, sealed all seams with foundation tape, and added a mechanical vent tied to the HVAC return. Relative humidity dropped from 78% to 52% within two weeks. The crew’s photo record showed the full seam sequence, and the written price was delivered before anyone entered the crawl space.
Spray Foam Insulation, Wallis Ranch
A Wallis Ranch homeowner was converting their attached garage to an office and needed the exterior walls brought to code without losing floor space. We applied 2 inches of closed-cell Icynene spray foam, achieving R-14 in a 2×4 wall with full air sealing in one pass. The blower-door test showed a 34% reduction in envelope leakage compared to the main house baseline. Written scope specified the foam thickness, brand, and expected R-value before application started.
Attic Air Sealing & Blown-In Insulation, Seven Springs
The Seven Springs home had a 12-degree temperature swing between upstairs and downstairs every August afternoon. We found a 4-inch gap around the masonry chimney chase and dozens of unsealed wire penetrations. After sealing with fire-rated caulk and sheet metal dams, we blew in Johns Manville fiberglass to R-49. The blower-door reading dropped from 4,200 CFM50 to 2,400. The homeowner received the before-and-after numbers, the full photo record, and the written warranty under our 365-Day Done Right Promise.
Radiant Barrier Installation, Oak Valley
An Oak Valley two-story with a south-facing roof deck was hitting 148 degrees in the attic by 3 p.m. in July. We installed a perforated radiant barrier to the underside of the rafters, maintaining the existing R-30 blown-in insulation on the attic floor. Attic peak temperature dropped to 112 degrees the following week. The photo record showed the staple pattern and the cleared ventilation channels we maintained per Cupertino’s attic ventilation code requirements.
Attic Cleaning & Rodent Proofing, Garden Gate
A Garden Gate homeowner heard scratching in the ceiling for three weeks before calling. We removed soiled insulation, sanitized the deck with enzyme treatment, installed 1/4-inch hardware cloth over all roof vent gaps, and sealed the fascia-to-roof junctions with copper mesh and polyurethane. New Rockwool blown-in insulation went to R-38. The documented photo record included close-ups of every sealed entry point and the full sanitization sequence. Written price covered removal, sanitization, proofing, and reinsulation as separate line items.
What Every Job Includes
These aren’t cherry-picked results. Every Cupertino job we complete follows the same sequence:
- Written price before any work starts - flat price, written scope, written warranty, delivered before anyone lifts a tool. Haven Standard Clause 1.
- Sealed first, then insulated - we don’t blow material over an unsealed attic floor. Air sealing of top plates, can lights, and penetrations is completed and photographed before insulation is added.
- Before-and-after blower-door numbers - on applicable jobs, you get the pressurization measurement that shows, in one figure, how much conditioned air your home was losing before and after.
- Documented Photo Record - included on every visit, not available on request. You see what we saw.
- 365-Day Done Right Promise - if it’s not done right, we make it right.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Before
AfterWant Results Like These?
Call (831) 217-8521 and a live person will answer, 24/7. We’ll schedule a free assessment, deliver a written price before any work starts, and show you exactly what your home’s envelope looks like now and what it could be. Most attic insulation jobs in Cupertino run between $2,800 and $5,400 depending on square footage, existing material condition, and whether air sealing is needed. Bring us any competing written estimate for a free second opinion - we’ll read it with you line by line.
Written by Wes Okafor, Owner at Topside Attic Insulation Cupertino, serving Cupertino since 2016.