Air sealing services in Santa Cruz CA - a tighter house that still breathes right

Best-practice guidance says yes, a blower door test, which uses a big fan in a doorway to measure how airtight the house is, should come before the work, and the result gives you a target so the job has a clear goal. The test can pull some dust and pollen inside and has been known to lift vinyl flooring that isn't glued down. We can talk through whether it makes sense for your house at the estimate.

You can usually handle the obvious leaks yourself, like the gaps around door frames and pipes that run through outside walls. What a do-it-yourself job won't find is the small stuff, especially in the attic of an existing house where insulation covers it, and that's usually where our installers spend their time.

It is when the checks come first. If you have fuel-burning equipment that vents by natural draft, guidance calls for a combustion safety test to make sure fumes aren't back-drafting or spilling into the house, and any problem gets fixed before sealing goes ahead. Sealing can also trap pollutants like carbon monoxide, radon and the fumes that come off paints and cleaners, which can mean adding ventilation fans or fixing the source, so I'd rather plan for that up front than surprise you partway through.

California requires a Contractors State License Board license whenever the job needs a building permit, uses employee labor or costs $1,000 or more in labor and materials. A job is exempt only if it needs no permit, uses no employees and totals less than $1,000, and a bigger project can't be broken into smaller contracts to get under that line. The state also has a license class just for insulation, covering any material installed to control temperature or sound.

There's no set price, because it comes down to how much sealing your house actually needs and what work goes alongside it. Closing the gaps and topping up with blown-in fill, loose insulation blown through a hose, is usually the better value, while sprayed foam costs more because it seals and insulates at once, and I'd only steer you toward foam when the ductwork lives up in the attic. If money's tight, check whether you qualify for the state's weatherization program, which works with local providers to install weatherization and energy efficiency measures for low-income homeowners and renters.

Narrow gaps get caulk, foam or spray sealant, and bigger openings get rigid blocking sealed in place. Fluffy insulation slows heat but doesn't stop air, so piling more of it over an open gap just leaves the draft fighting the insulation.