GreenFiber Attic Insulation Nationwide

GreenFiber Attic Insulation: The San Francisco Owner’s Guide

GreenFiber attic insulation in San Francisco typically costs $1,800 to $4,200 installed, depending on attic square footage and the R-value you’re targeting. We stock GreenFiber SANCTUARY and Cellulose blown-in products on our trucks, and most San Francisco attics can be done same-day. Homeowners usually find us after noticing cold rooms upstairs, a spike in their PG&E bill, or old insulation that’s settled flat and stopped doing its job.

Call (559) 245-9792

GreenFiber’s cellulose insulation is made from up to 85% recycled paper fiber treated with borates for fire resistance and pest deterrence. In San Francisco’s damp, fog-driven climate, that borate treatment matters more than most people realize. We’ve pulled failed fiberglass out of Sunset District attics that was matted down to half its original depth by years of moisture. GreenFiber’s treated cellulose holds its loft longer in our coastal air, but it does settle over time, and when it settles, performance drops.

If your attic has GreenFiber that’s no longer hitting its marked R-value, or you’re adding insulation to an older home and want to match what’s already up there, we’ll get it right the first time. Written price before we start, and the work is covered for 365 days.

Which GreenFiber Models This Applies To

We install and top off two GreenFiber product lines: SANCTUARY by GreenFiber, their all-borate blow-in cellulose, and GreenFiber Cellulose Blown-In Insulation, the standard product you’ll find in most existing attics. If your attic already has GreenFiber and you want to add more, the answer is almost always to top off with SANCTUARY or standard cellulose rather than switch materials mid-attic. Mixing materials in an attic creates uneven thermal performance and can trap moisture between layers.

Identifying what you have is straightforward. Look for the GreenFiber coverage chart stapled to an attic joist or truss, which lists the square footage, bag count, and installed depth for the original R-value. No chart? Measure the loose-fill depth with a yardstick. In San Francisco, energy code calls for R-38 in attic floors for most homes, which means roughly 10 to 11 inches of settled GreenFiber cellulose. If you’re measuring 5 or 6 inches, you’re sitting at roughly R-19 to R-22, and your attic is under-insulated.

For this specific product, we use OEM GreenFiber bags on nearly every job. GreenFiber’s borate formula is consistent bag to bag, and when you’re topping off an existing cellulose install, matching the chemistry matters. Aftermarket or generic cellulose can use different fire-retardant treatments, and layering two different chemistries across one attic floor is a shortcut we won’t take. We do stock Reflectix radiant barrier material on our trucks for San Francisco attics where a foil layer under the roof deck makes sense against summer heat gain, but it plays a supporting role, not a replacement for the blow-in itself.

Alden Insulation San Francisco is an independent installer. We’re not affiliated with GreenFiber directly, but we install and remove their products regularly and know their specs and coverage math cold.

Signs Your GreenFiber Attic Insulation Is Failing

• Upstairs rooms won’t hold temperature. GreenFiber that’s settled below its intended depth loses R-value fast. If the upstairs runs 6 to 8 degrees warmer than the main floor in summer, the attic floor is losing its thermal barrier.
• Your PG&E bill climbs without a change in usage. When loose-fill cellulose settles or gets disturbed, conditioned air moves through the ceiling plane more freely. You’re paying to heat and cool an attic vented to the outside.
• You can see bare joists or uneven depth. GreenFiber should sit level across the attic floor. If wind from ridge or gable vents has drifted it into low spots, or a previous contractor walked paths through it, those bare areas are thermal holes.
• Drafts around ceiling light fixtures and attic hatches. Insulation that’s thinned out lets air move around penetrations. In San Francisco’s Victorian and Edwardian stock, those ceiling penetrations are numerous, and the air movement is constant.
• Pest activity in the attic. GreenFiber’s borate treatment deters insects but doesn’t stop rodents from burrowing. Rats will tunnel through loose-fill and compress it into dense, useless mats. If you’ve had rodent work done, the insulation likely needs topping off or removal.

Replacement Cost & What’s Included

For a typical San Francisco attic of 1,000 to 1,500 square feet, installing GreenFiber SANCTUARY to R-38 runs $1,800 to $4,200. Smaller attics or top-off jobs run lower; attics with steep pitches, limited access, or old insulation that requires removal run higher. If we’re pulling failed fiberglass or rodent-damaged material first, removal adds $1 to $2 per square foot depending on depth and condition.

Every GreenFiber quote from Alden includes the bags of cellulose, machine time, labor, and cleanup. The price we write down before the job is the price on the invoice. No adjustments at the door. The work itself is covered by the 365-Day Done Right Promise: if the insulation fails or doesn’t perform inside a year, we come back at no charge. That’s a written guarantee, not a verbal one.

You can call us at (559) 245-9792 for an exact number on your attic. The estimate is free, and we’ll tell you plainly whether a top-off is enough or a full removal makes more sense.

DIY or Call Us?

You can safely do two things yourself: measure your current depth with a yardstick and check your attic access for obvious signs of settling or pest damage. That’s useful information, and it’ll help you know whether a contractor is being straight with you.

What you shouldn’t do is rent a blower and start filling your attic without air sealing first. GreenFiber dropped over a leaky attic floor covers the leaks without stopping them. You’ll still move conditioned air into the attic, and the insulation becomes a filter that collects dust and moisture over time. Also, working in a San Francisco attic on a warm afternoon without proper ventilation can push temperatures over 120 degrees. It dehydrates you faster than most people expect.

If you’d rather have it done right and guaranteed in writing, call us at (559) 245-9792. We’ll bring the machine, the bags, and a crew that shows up in uniform inside the window we promised.

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