We track down and seal the leaks that make a house drafty and expensive: top plates, can lights, rim joists, ducts, and penetrations. Often the highest-payback work we do.
You can pile insulation into an attic all day, but if the house leaks air, it'll still feel drafty and cost a fortune to heat. Warm, wet air sneaks out through gaps you can't see: the top plates where the walls meet the attic, around can lights and the attic hatch, the rim joist down in the crawlspace, plumbing and wiring penetrations, and leaky ducts. In our climate that escaping air carries moisture with it, which is its own problem.
Air sealing finds and closes those leaks, and dollar for dollar it's usually the highest-payback work we do. We seal the attic floor, the rim joist, the penetrations, and the ducts with caulk, foam, gaskets, and weatherstrip. A lot of people are surprised how much warmer and quieter the house gets from sealing alone, before we add any insulation. Air sealing is also a key part of qualifying for the PSE and weatherization rebates, so it often pays for itself twice.
What it actually costs.
Air Sealing & Weatherization $800 to $3,000
Home sizeMore square footage, more leaks to find and seal
Leak countAn old, leaky house takes more sealing
AccessAttic and crawlspace clearance affect the work
Duct sealingLeaky duct runs add scope
Our four-step process.
Free assessment
We find the leaks, in the attic, the crawlspace, and around the house, sometimes with a blower-door style check.
Seal the big leaks first
We seal the attic top plates, can lights, the hatch, and the rim joist, where most of the air is moving.
Seal the rest
We close penetrations, seal ducts, and weatherstrip where it counts.
Set up the rebate
Air sealing helps qualify your home for the PSE or weatherization rebate, and we help you file.
Why hire a local crew for this work.
Often the highest-payback work in the whole house
Seals the leaks insulation alone can't fix
Less moisture carried into the attic and walls
A warmer, quieter, less drafty house right away
Key to qualifying for PSE and weatherization rebates
Frequently asked questions.
How much does air sealing cost in Bellingham?
Air sealing in Bellingham usually runs $800 to $3,000, depending on the size of the house and how leaky it is. It's often the cheapest work we do and the highest payback, because sealing the air leaks usually saves more on the heating bill than the same money spent on insulation alone. It also helps qualify your home for the PSE or weatherization rebate.
Is air sealing really worth it before adding insulation?
Yes, and it's the step most people skip. In a typical Bellingham home the air leaks, around top plates, can lights, and the rim joist, lose more heat than the missing R-value does. Sealing them first means the insulation you add actually performs instead of letting warm, wet air leak right past it. We always seal before we insulate for that reason.
What does air sealing actually involve?
We find the leaks and close them. That means caulking and foaming the attic top plates, sealing and covering can lights, weatherstripping the attic hatch, foaming the rim joist down in the crawlspace, sealing plumbing and wiring penetrations, and sealing leaky duct runs. The goal is to stop the warm, wet air that's escaping and driving up your heating bill.
Ready for a free air sealing & weatherization quote?
Tell us about your home, we'll reply within 15 minutes during business hours and set up a free assessment.
Air Sealing & Weatherization across Whatcom County.
Every neighborhood we serve has its own story, century-old walls in the Lettered Streets, cold floors over the crawlspaces in Columbia, damp ground out by the lake. Pick your area for local notes: