Insulation Before & After in San Francisco, CA
Photos tell the truth faster than any sales pitch. In a city where summer fog rolls through the Sunset and winter winds whip off the bay into Pacific Heights, the difference between a poorly insulated attic and a properly sealed one is visible the moment you open the hatch. Below are real project scenarios we’ve handled across San Francisco. The photos are coming as we build this gallery out, but the stories behind them are the work we do every week.
Recent Transformations
Attic Insulation Removal and Replacement in the Outer Sunset
Before
AfterThe problem: a 1940s row house with original rock wool batting that had settled to roughly R-11 and was holding moisture from years of fog exposure. What we did: removed the old material, air-sealed the attic floor, and blew in GreenFiber cellulose to R-38 across 1,100 square feet. The result: the upstairs bedrooms stopped losing heat by 9 p.m., and the homeowner noticed the furnace kicking on noticeably less during the first week. In the Outer Sunset, where salt air and damp are constant, getting old insulation out first is the step most people skip.
Blown-In Insulation for a Drafty Marina District Flat
Before
AfterThe problem: a top-floor unit with vaulted ceilings in the Marina, where the living room faced the bay and leaked heat all winter. The attic access was tight, and the existing fiberglass had gaps you could see daylight through. What we did: dense-packed Owens Corning blown-in fiberglass to R-44, working through two small access points without disturbing the ceiling below. The result: the temperature difference between the living room and the hallway went from a constant seven degrees to under two. We see this exact scenario all over the Marina and Russian Hill, where older flats were built for looks, not thermal performance.
Insulation Removal After a Roof Leak in Noe Valley
Before
AfterThe problem: a roof leak had soaked an entire corner of blown-in insulation, creating mold risk and compressing the material to the point where R-value was gone. The homeowners could smell it before they saw it. What we did: removed every trace of the wet material, treated the decking, let it dry properly, and reinstalled Johns Manville blown-in fiberglass to R-38 once moisture readings came back clean. The result: the musty smell disappeared within 48 hours, and the corner of the bedroom returned to the same temperature as the rest of the floor. Rushing this job without full removal would have trapped moisture against the ceiling joists.
Attic Insulation Top-Up in the Richmond District
The problem: a 1960s home with some original insulation, roughly R-19 in places but uneven, with bare patches over two bedrooms. The homeowners didn’t need a full removal. They needed the attic brought up to current code. What we did: layered Knauf blown-in fiberglass over the existing material to bring the whole attic to a consistent R-42, and built a raised platform around the furnace so future maintenance wouldn’t compress it. The result: a quieter house, a warmer nursery, and utility bills that finally matched what the neighbors said they were paying. Sometimes the right call is adding rather than replacing.
Blown-In Insulation for a Bernal Heights Craftsman With No Attic Access
The problem: a classic Bernal Heights craftsman with a sealed attic that had never held insulation. No walkable access, no hatch big enough for a person. The upper floor baked in September and froze in January. What we did: cut two small access points in closets, fed our hose through, and blew in CertainTeed fiberglass to R-38 across roughly 900 square feet. The result: the second floor finally held temperature, and the access points were patched so cleanly the homeowner can’t find them anymore. This is a common job for us in the older hillside neighborhoods, where original construction never accounted for insulation.
Want Results Like These?
Every attic in San Francisco has its own set of problems, whether it’s fog-driven moisture in the Sunset, salt air in the Marina, or 100-year-old framing in Bernal Heights. We’ll give you a written price before any work starts, and every job is covered by a written 365-Day Done Right Promise. If it fails within a year, we return at no charge. Call (559) 245-9792 for a free estimate.
Written by Bryce Holloway, Owner at Alden Insulation San Francisco, serving San Francisco since 2002.