Trusted Attic Insulation for San Francisco Homeowners
Most San Francisco attics are under-insulated by 30 to 50 percent, and that gap shows up every month in rooms that never hold heat in July fog or stay too warm in a September heat wave. We’re Thistledown Insulation San Francisco, a Cedarwell-family company founded in 2003, and we’ve spent two decades correcting what old fiberglass, rodent damage, and quick-flip contractors left behind. Attic insulation in San Francisco is not one-size-fits-all: a 1920s Richmond District flat needs different treatment than a Sunset stucco box or a hillside home in Noe Valley. We take the time to explain exactly what’s going on up there, put the price in writing before any work starts, and leave your hallway floors as clean as we found them. Call (341) 247-0222 and a live person answers, day or night.
Blown In Insulation
Blown In Insulation is loose-fill fiberglass or cellulose blown into attic cavities with a hose, and it remains the most common retrofit choice for San Francisco homes with odd joist spacing, low-clearance attics, or existing insulation we don’t want to fully disturb. The material settles into gaps that batts simply can’t reach, which is why we recommend it so often in older Marina and Mission District houses. Depending on square footage and depth, blown in insulation in San Francisco typically falls between $1,200 and $3,400, and you’ll always see your exact number in writing before the machine gets unloaded.
Cellulose vs. Fiberglass
Both can perform well, but they behave differently in San Francisco’s damp marine air. Cellulose, like GreenFiber, resists airflow better and holds more R-value per inch, but it must stay dry and we inspect for any sign of moisture before recommending it. Fiberglass is naturally moisture-resistant and often the smarter pick for attic spaces that run humid even with proper venting.
Over Existing Insulation
Sometimes the smartest, least disruptive move is an Attic Insulation Top-Up, blowing new insulation over what’s already there, especially if the old layer isn’t vermin-soiled or water-damaged. We check the existing R-value first and give you a straight answer about whether topping off makes sense or whether full removal is the better long-term call.
Insulation Contractors
Insulation Contractors range from one-truck operations that quote by phone sight unseen to full-service companies like Thistledown Insulation San Francisco that send a trained technician into the attic before any number is finalized. Hiring someone who actually looks at the space matters in this city, because San Francisco attics hide surprises: knob-and-tube wiring that must not be buried, undersized bath vents, or decades of pigeon debris under the eaves. Our technicians are background-checked, uniformed, and trained on all eight brands we install, and our typical attic insulation projects run from $1,200 to $3,400 for blown-in work, with spray foam starting higher. You’ll get a written price that covers the entire job, no add-on surprises.
What to Ask Before You Sign
Ask whether the crew wears shoe covers and drop cloths, whether the quote includes cleanup, and whether the person doing the work is the same person doing the inspection. We answer those questions the same way every time: yes, yes, and yes. The number on the quote is the number on the invoice.
Licensing, Insurance, and Background Checks
Every technician who walks through your front door has passed a background check and wears a Thistledown uniform, so you know exactly who’s going upstairs while your kids are home. We carry full insurance and bonding, and our 365-Day Done Right Promise means if something isn’t right a year later, we come back and make it right without a debate.
Attic Ventilation
Attic Ventilation is the system of intake and exhaust airflow that keeps a San Francisco attic from trapping moisture against the underside of the roof deck, which is the starting point for mold, warped plywood, and insulation that loses its effectiveness. We assess venting on every insulation job because adding insulation to a poorly vented attic can actually make moisture problems worse by trapping humid air below the new layer, which is why Attic Baffles & Ventilation Prep is part of our standard process. Expect ventilation analysis as part of every free estimate; adding or correcting vents typically ranges from $400 to $2,800 depending on roof geometry and existing vents.
Signs of Poor Airflow
Rust on exposed roofing nails inside the attic, damp insulation in winter, or a musty smell after rain all point to airflow problems. In neighborhoods like West Portal and Forest Hill where trees shade roofs for most of the day, we see more condensation issues than in sun-baked Outer Sunset homes.
Balancing Intake and Exhaust
A working attic needs roughly equal intake at the eaves and exhaust near the ridge. We measure the existing net-free vent area and calculate what’s missing, then recommend a fix that works with your roofline rather than poking holes where they’ll create new problems.
Radiant Barrier
Radiant Barrier is a reflective foil material installed under the roofline that reduces the heat radiating down into your attic from a hot roof, which matters most in San Francisco during those late-summer and early-fall stretches when inland heat reaches the peninsula. It’s not a substitute for insulation, but in homes where the attic gets punishingly hot, a radiant barrier can lower upper-floor temperatures enough to notice. Depending on attic size and whether we install it during an insulation job or as a standalone project, radiant barrier in San Francisco typically runs $1,500 to $4,200. We’ll give you the exact number before any material gets ordered.
How It Works
The foil reflects radiant heat rather than absorbing it, so less of it transfers through to your living space below. It may not show much measurable benefit in fog-heavy neighborhoods like the Outer Richmond, but in the Mission, Bernal Heights, and Potrero Hill, where summer sun beats down for days at a time, it can make a real difference.
Installing With Insulation
If we’re already in the attic adding blown-in or Attic Batt Insulation, adding a radiant barrier is more cost-effective than doing it later as a separate visit. We’ll show you what makes sense for your specific house and what you can skip, because we’d rather under-sell you than sell you a product your attic doesn’t need.
Attic Cleaning Services
Attic Cleaning Services cover the removal of old rodent droppings, nesting debris, dust, and construction debris before new insulation goes in or when an attic has simply been neglected for decades. If your San Francisco attic hasn’t been entered since the previous owner left, there’s a good chance it’s carrying a load of pigeon droppings, rat nests, or decades of urban grime. We handle cleanup with the same discipline as the insulation itself: HEPA-filtered vacuums, bagged waste carried out through the house with drop cloths protecting your floors, and full sanitizing before any new material goes in. Attic cleaning in San Francisco typically falls between $1,800 and $4,500, depending on the size of the space and the severity of contamination.
Why San Francisco Attics Get So Dirty
Sea air pushes moisture into vents, and our older housing stock often lacks proper sealing at the eaves, which invites birds and rodents into the warm space between the ceiling and the roof. Left alone, that debris compresses your insulation, cuts R-value, and can introduce allergens into the home’s air.
What We Use
We bring in commercial HEPA vacuums and sanitizing agents that are appropriate for enclosed home spaces, never harsh chemicals that would linger in the air your family breathes. After cleaning, we photograph the result before we come down from the attic ladder.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Attic Mold Removal
Attic Mold Removal addresses fungal growth on roof sheathing and roof framing before it spreads, and in coastal climates like San Francisco’s, it’s a job that needs to be handled alongside whatever moisture issue caused it, or it comes right back. Mold in a San Francisco attic is almost always a symptom of bad venting, a leaking roof boot, or a bathroom fan vented directly into the attic instead of outdoors. We identify the moisture source, remediate the affected area, and then correct the airflow so the problem doesn’t return before the next rainy season. Depending on the extent of the affected area, attic mold removal in San Francisco generally ranges from $2,000 to $6,500, and you’ll have a written number after we look at the space.
Moisture First, Then Mold
If you remove mold but leave the leak or the condensation source, you’ll pay for the same job again in a year. Our inspection looks for bathroom fans venting into the attic, unsealed hatchways, missing vent baffles, and roof penetrations that leak, because those are the reasons mold took hold in the first place.
Safe Products for Your Home
We choose antimicrobial treatments that are designed for occupied residential spaces and won’t leave your attic reeking of bleach for weeks. Where pets or small children are in the home during the job, we prefer options that don’t require the family to vacate.
Attic Insulation Removal
Attic Insulation Replacement often starts with removal: we clear out old, contaminated, or failing insulation so a fresh, correctly installed layer can go in, and it’s a job we do more often than most people expect in San Francisco’s older housing stock. If rodents have nested in your fiberglass, if a roof leak soaked the batts into a matted mess, or if the previous owner installed insulation incorrectly, pulling it out is the only honest first step, not a corner we can cut. We bag the old material in the attic, lower it out through the hatch or a removal port, and run a HEPA vacuum to catch what’s left behind. Attic insulation removal in San Francisco typically runs from $800 to $2,500 depending on the material and the attic’s accessibility.
When You Need It
Blown-in insulation that’s been heavily soiled by rodents is not worth saving, and trying to blow new material over it just buries the problem. We also recommend removal when old insulation contains vermiculite that should be tested, or when it has compressed to the point that it’s providing almost no R-value.
What Happens After Removal
Once the old insulation is out, we sanitize the exposed surfaces, seal any gaps where pests got in, and give you a clear recommendation for what goes back. Every removal job ends with the same clean-up photo before we leave, and if you’re not adding new insulation yet, we tell you that plainly.
How Much Does Attic Insulation Cost in San Francisco?
Attic insulation in San Francisco typically runs between $1,200 and $6,500 depending on the type of insulation, the condition of the existing attic, and whether you’re adding venting or removal at the same time. A straightforward blown-in job over an accessible, clean attic in a Sunset two-bedroom usually starts around $1,200 to $1,800. A larger home in the Richmond or Marina with attic mold and old insulation that needs removal first could reasonably land between $5,000 and $6,500 all-in. Spray foam costs more per square foot but often eliminates the need for separate air sealing, and we’ll show you a product comparison before you choose. The factors that change your price: the square footage of the attic floor, the R-value you’re targeting, the material you select (fiberglass, cellulose, cotton, rock wool, or spray foam like Icynene or Demilec), whether old insulation needs removal, and how easily a technician can work in the space. Low-clearance attics or cathedral ceilings add labor time. To avoid overpaying, be wary of any quote given before someone sets foot in the attic, and be suspicious of prices that seem too good to be true because under-insulating is the most expensive mistake you can make. Every Thistledown estimate in San Francisco is free, includes a written price, and covers the entire job, including cleanup.
Brands We Service
We install and maintain insulation from eight manufacturers so you’re not stuck with whatever a single-brand contractor happens to stock. Owens Corning and Johns Manville fiberglass products are workhorses for San Francisco’s cool, damp climate, and we match their density and R-value to your specific attic depth rather than pulling a generic number off a chart. Knauf and CertainTeed both offer excellent batt and board insulation that fits cleanly between unusual joist spacing in older homes.
When a client specifically asks for lower-impact materials, Rockwool stone wool offers fire resistance and sound attenuation that can matter in attached housing, and GreenFiber cellulose gives us a recycled-content option. For homes where air sealing is the primary goal, Icynene and Demilec spray foam products let us create a continuous thermal envelope, and we’ve seen both perform in San Francisco’s marine air when installed correctly. Whether you have one of these brands specified by an architect or you want a recommendation based on what’s actually in your attic, we can help.
Signs You Need a Pro Right Now
- Rooms above the garage never hold temperature. If the room over your garage is always freezing in summer fog or roasting during a heat wave, the insulation between the garage ceiling and that floor is probably missing or failed. We see this constantly in Noe Valley and Glen Park homes built before the 1970s.
- Your heating bill climbed but your comfort didn’t. A furnace working harder to hit the same thermostat setting usually means heat is escaping through the attic. That’s money leaving through the top of the house every month, and it’s not coming back.
- You can see the joists through the insulation. If the attic floor joists are visible above the insulation, the material has compressed or settled well below useful levels. Most San Francisco attics we inspect have around R-19 when they need R-38 to R-60.
- You found rodent droppings or nesting material up there. Pests living in your insulation are ruining it, and the diseases they can carry are the last thing you want drifting down into your living space. This is the most common reason we do full removal jobs.
- The upstairs rooms smell musty after rain. That odor means moisture is getting into the attic, and moisture in the attic means mold is either already present or coming soon. In a city that gets 23 inches of rain a year, this one doesn’t fix itself.
Our Process, Step by Step
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You call and a real person answers. No phone tree. We ask a few questions about what you’re seeing and schedule a free estimate at a time that works for your family. If it’s after hours, the same live person still picks up.
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A background-checked technician arrives on time, in uniform. Shoe covers go on at the door and drop cloths are laid in the hallway before the attic ladder comes down. We inspect the attic, measure the existing R-value, check for moisture and air leaks, and document everything with photos.
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We walk you through what we saw and what it costs. You get a written price that covers the entire job from start to cleanup. We explain what product we’d recommend and why, and we tell you plainly if there’s an issue like mold or wiring that changes the plan.
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Our crew does the work, quietly and cleanly. If your baby is napping, we use quiet tools and keep noise to a minimum. The attic work happens while your floors stay covered, and we treat the space like it’s our own home.
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You get a cleanup photo before we leave. We photograph the finished work and the clean area below the attic hatch, then we walk you through what was installed. If anything isn’t right in the next 365 days, we come back and make it right under our Done Right Promise.
Our Service Area Near San Francisco
Thistledown Insulation San Francisco serves homeowners throughout San Francisco and the surrounding Bay Area. We regularly work in Richmond, Hayward, Daly City, South San Francisco, Pacifica, San Bruno, and Oakland. For homes in the city, we’re typically able to schedule estimates within 24 to 48 hours. If you’re farther out but unsure, call (341) 247-0222 and we’ll tell you right away whether we can get to your attic. You can also start with our home page for an overview of everything we do.
Serving San Francisco, CA - Our Local Coverage Area
We’re based in the San Francisco area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions About Attic Insulation in San Francisco
Attic insulation is the material installed between your attic floor joists or along the roofline that slows heat transfer between your living space and the outdoors. In San Francisco, where we’re nine degrees above the national average for heating and cooling season, the right insulation keeps upstairs rooms comfortable year-round and lowers what you pay to run your furnace. The most common materials we install are fiberglass, cellulose, rock wool, and spray foam, and the right one depends on your attic’s construction, moisture level, and existing insulation.
Most blown-in attic insulation jobs in San Francisco are completed in a single day, including setup and cleanup. A larger job involving removal, sanitizing, and new insulation might take two days, and spray foam has additional curing time before the space is fully done. We’ll give you a clear time window when we provide your written estimate, and we work quietly enough that you can stay home while the job happens.
Attic insulation in San Francisco generally runs from $1,200 to $6,500, with the exact number depending on insulation type, attic square footage, and whether removal or venting work is part of the job. Your written estimate covers everything, including cleanup, so the number you approve is the number you pay. Call (341) 247-0222 for a free quote, and a live person will help you schedule the visit.
Yes, we install and maintain all three, along with Knauf, Rockwool, Icynene, Demilec, and GreenFiber. If a product from one of these manufacturers is already in your attic and you want to add to it or replace it, we can match what’s there or recommend a better option. Give us a call and tell us what you have, and we’ll tell you what’s possible.
We answer calls 24 hours a day, 7 days a week, and for urgent situations like a roof leak that’s soaked your insulation or a pest problem that’s tearing it apart, we do our best to get a technician out the same day. Even if we can’t have someone on-site immediately, we’ll be honest with you about the next available window and what you should or shouldn’t do in the meantime. Call (341) 247-0222 and a live person will give you a straight answer.
Every job we do is backed by our 365-Day Done Right Promise. If something isn’t right within a year, we come back and make it right without a debate and without fine print. Beyond that, the insulation products we install carry manufacturer warranties for their expected lifespan, and we’ll explain exactly what’s covered before you sign anything.
You don’t need to do much. We’ll ask you to clear a small path near the attic hatch and keep pets in a comfortable room while our technicians are working. We handle the rest: drop cloths, shoe covers, cord management, and all cleanup. If there’s anything specific about your home or family we should know, just tell us when you call, and we’ll plan around it.
Schedule Your Attic Insulation Service in San Francisco Today
A colder upstairs shouldn’t be the thing you just live with in this city. Call Thistledown Insulation San Francisco at (341) 247-0222 for a free, no-obligation estimate with a written price, a background-checked crew, and a 365-Day Done Right Promise on every job. A live person answers around the clock.
Written by Neil Barron, Owner at Thistledown Insulation San Francisco, serving San Francisco since 2003.