GreenFiber Blown In Insulation in San Francisco: What to Know First
We install and repair GreenFiber blown in insulation in San Francisco for homeowners across the city, from the Sunset to Bernal Heights. Most GreenFiber blown in jobs run $1,200 to $3,800 depending on square footage, current R-value, and whether we’re topping off an attic or starting from bare joists. If your attic has settled GreenFiber or you’re planning a blow-in from scratch, call (559) 245-9792 and we’ll give you a straight written price before any work starts.
This page is for San Francisco homeowners who already have GreenFiber in their attic or are considering it for a blown in insulation project. You’ll find the failure modes we see most on GreenFiber jobs, what they cost to fix, and the process we follow from first call to final cleanup. If you’re in a Victorian in Noe Valley with original lathe walls or a 1950s Sunset District box with a shallow attic, you’re in the right place.
How GreenFiber Products Fail – and How We Fix Them
GreenFiber makes a solid blown in product, mostly cellulose from recycled paper stock treated with borates for fire and pest resistance. That said, after years of pulling GreenFiber out of San Francisco attics, we know exactly where it goes wrong. Here’s what we find:
- GreenFiber Sanctu-Fill settles in shallow-attic homes. Sanctu-Fill is GreenFiber’s workhorse loose-fill cellulose, and in San Francisco homes with 2×6 ceiling joists, we routinely find it settled 30 to 40 percent below the intended R-value. Coastal fog pushes moisture into attics, the cellulose compacts under its own weight, and you lose R-value without ever touching the stuff. We air-seal the floor, top off to the correct depth, and verify with a thermal scan.
- GreenFiber Cocoon dense-pack shrinks in older wall cavities. Cocoon is GreenFiber’s dense-pack line for walls, and in Victorian and Edwardian homes, irregular stud bays from 1880 to 1920 leave voids where the original install skipped. Homeowners notice cold walls on foggy mornings and occasional draft lines along baseboards. We pull a borescope through key bays, map the voids, and re-densify to a proper 3.5 pounds per cubic foot.
- Borates leach from GreenFiber in roof-leak zones. GreenFiber’s borate treatment handles moisture reasonably well, but repeated roof leaks over a San Francisco winter can leach the treatment and leave the cellulose fluffy and vulnerable. We see this most in flat-roof Sunset and Richmond homes where roof drains back up. The fix starts with the leak, then we remove the compromised material and blow in new GreenFiber with a moisture meter check at close.
- Improper initial R-value on retrofit jobs. GreenFiber specifies coverage and bag count per square foot for a target R-value. When a prior contractor under-shot the bag count, the attic looks fine but tests below the code minimum R-38 for San Francisco. We verify with a depth gauge across ten points, not just the access hatch, then top off or strip and re-blow as needed.
- GreenFiber Insulation Shield over unsealed bypasses wastes the R-value. Insulation Shield is GreenFiber’s borate-only fiber line, and it performs fine as thermal material, but we’ve pulled fiber back from attic floors and found unsealed top plates, plumbing chases, and recessed cans running straight into the house. The insulation wasn’t failing; the air sealing was never there. We seal every bypass before any GreenFiber goes back down.
One thing to know if you’re comparing GreenFiber to fiberglass: cellulose holds its R-value per inch slightly better at colder temperatures, which matters in San Francisco attics that swing from 50 to 110 degrees. That said, it’s heavier, so older ceilings with cracked plaster need a deflection check before we load up. We’ll tell you honestly whether GreenFiber is right for your house or whether a different product makes more sense.
Our GreenFiber Blown In Insulation Process
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Call and describe your attic. A live person answers 24/7. We’ll ask about square footage, current insulation, any moisture stains, and when the house was built. That tells us what to bring.
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On-site attic walk-through. A background-checked, uniformed technician inspects the attic floor, air sealing, ventilation, and any existing GreenFiber. We measure depth points and check for moisture with a meter.
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Written scope and price in your hand. Before any tool comes off the truck, you get a line-item estimate covering removal (if needed), air sealing, the GreenFiber product and target R-value, and cleanup. No revisions at the door.
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The blow-in or top-off. We run GreenFiber through a calibrated blower, checking bag count against square footage to hit the specified R-value, not just eyeballing depth. For wall dense-pack, we verify density with a gauge as we go.
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Verification and cleanup. A depth gauge pass across the full attic, a thermal scan where warranted, and a clean floor before we leave. You get a one-page summary of what was installed, the R-value achieved, and the bag count used.
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365-Day Done Right Promise. Every job is covered in writing for a full year. If the insulation settles below spec or a fixed area fails, we return at no charge. That’s part of The Garrison Standard, and we put it on every invoice.
Bryce Holloway runs the crew in San Francisco, and his rule is simple: we don’t leave an attic until the depth gauge matches the quote. That comes from two decades of insulation work, a fair stretch of it spent correcting rushed installs in Sunset District homes where the fog picks apart shoddy work within a season.
What GreenFiber Blown In Insulation Costs in San Francisco
Here’s what you can expect to pay in San Francisco for GreenFiber work, depending on what you’re starting with:
- Attic top-off over existing insulation: $900 to $1,800 for a typical 800 to 1,200 square foot attic, bringing existing material up to R-38 or R-49.
- Full attic blow-in from bare joists: $2,200 to $3,800 for an 800 to 1,200 square foot attic at R-38, including air sealing and baffles.
- Dense-pack sidewall insulation: $3 to $6 per square foot of wall surface, depending on access and whether we go in from the exterior or interior.
- GreenFiber removal and replacement: $1,500 to $3,000 when old material is compromised by moisture, pests, or prior improper install. Removal is charged separately from the new blow-in.
- Isolated moisture-damage repair: $400 to $1,200 for a partial removal in one corner or bay, depending on visible square footage and access.
The big price movers are attic access (pull-down stairs vs. a scuttle hole), current R-value, and how much air sealing is needed before the blow. A Victorian with a flat, tight attic will cost differently than a 1960s Sunset box with wide joist spacing. But here’s the thing: the number we quote is the number on the invoice. It’s in writing before work starts, and it doesn’t move. Call (559) 245-9792 for an exact figure on your attic. Estimates are free.
Why San Francisco Homeowners Call Alden Insulation San Francisco for GreenFiber Work
We’re independently owned and operated, held to The Garrison Standard, and every GreenFiber job gets a written price and a written 365-Day Done Right Promise. If it fails within a year, we return at no charge. No fine print. No phone tag with a call center. When you call (559) 245-9792, a live person answers, day or night, and if your attic is losing heat on a foggy January night, we’ll move a crew out fast.
Our technicians work with GreenFiber regularly, but they also install Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, Demilec, and Reflectix. That matters because we’re not married to one product. If GreenFiber is right for your San Francisco attic, we’ll say so. If a different material does the job better for your specific house, we’ll tell you that too. The Garrison Code means we don’t upsell what you don’t need.
As an independent GreenFiber service provider, we’re not authorized by or affiliated with GreenFiber. But the work is done to manufacturer spec, and the guarantee is ours, in our name, for a full year.
FAQs
Yes. We install and remove GreenFiber blown in insulation throughout San Francisco as an independent GreenFiber service provider. We stock GreenFiber Sanctu-Fill and Cocoon, and we order additional lines same-day from local San Francisco suppliers when a job calls for it. Call (559) 245-9792 and we’ll tell you which GreenFiber product fits your attic and why.
For a standard attic top-off or blow-in, we typically schedule within three to five business days across San Francisco. Emergency work, like a roof leak that’s soaked your GreenFiber and is dripping into a ceiling, moves faster because the call line is live 24/7. We’ll give you a firm window when you book, and the technician arrives inside it, in uniform, background-checked.
If the GreenFiber is dry, pest-free, and just settled, a top-off is almost always cheaper than a full remove-and-replace. You’ll pay $900 to $1,800 for a top-off versus $1,500 to $3,000 for full removal and new blow-in. The exception is moisture-compromised material, which we won’t simply cover over. We’ll tell you which path your attic actually needs, along with a written price, before any work begins.
It shouldn’t, as long as the job includes proper baffles at the eaves and sealed air bypasses first. We install baffles on every GreenFiber blow-in in San Francisco where soffit vents are present, because blocked airflow rots roof decking in our fog climate faster than anywhere else. If we see ventilation problems during the walk-through, we flag them in the written estimate before insulation goes in.
San Francisco falls under DOE climate zone 3, which recommends R-30 to R-60 for attics, but we push R-38 minimum on almost every job because of the fog-driven moisture cycle. GreenFiber Sanctu-Fill hits R-38 at about 10.5 inches of settled depth in a typical attic. We verify depth with a gauge across the full attic, not just near the hatch, and we put the achieved R-value on your invoice.
If you’ve got a GreenFiber attic in San Francisco that’s running cold, settling, or showing signs of moisture, call (559) 245-9792. We’ll answer with a real person, schedule a walk-through, and put a written price in your hand before a single bag of insulation comes off the truck. The estimate is free, and the work is guaranteed for 365 days, in writing.
Written by Bryce Holloway, Owner, Alden Insulation San Francisco at Alden Insulation San Francisco, serving San Francisco and nearby areas.