Air Sealing in California

Licensed & insured Every company we put you through to holds current licensing and insurance.
Know what to ask You are told what actually decides the price, so you can judge a quote.
Someone local You are put through to a technician who works your area, not a call center three states away.
Calls answered 7 days Someone picks up seven days a week, weekends included.

Is it urgent?

Can wait

Not urgent, but it is the item with the best ratio of cost to result on this whole list, and in California it does double duty: the same gaps that lose conditioned air are the ones that let wildfire smoke into the house during an event.

Two things override everything on this page. If anyone has symptoms of carbon monoxide exposure — headache, nausea or dizziness that improves outdoors — leave the building and call the gas utility or the fire service, not a duct company. And if you can smell burning while the dryer is running, unplug it and leave it.

Signs to look for

Drafts near ceiling fixtures, the attic hatch or where an interior wall meets the ceiling
Dust streaking on the carpet at the edge of a room, which marks air moving through the floor or wall junction
Smoke or outdoor smells getting indoors quickly during a wildfire event
A room that is uncomfortable in a way more insulation has already failed to fix
Recessed can lights that are not the airtight type

How the work is done

Finding the leaks rather than sealing everywhere — a blower door and, where it helps, theatrical smoke or a thermal camera
Sealing at the ceiling plane and the rim joist, which is where most of the loss is in a California house
Using the right material for each gap: foam and caulk for small ones, rigid backing and mastic for large ones, fire-rated material at flues and chimneys
Retesting afterwards, so the improvement is a measured number rather than an assertion

In California specifically

California's Mediterranean on the coast, hot and dry inland climate and its housing stock — stucco ranch and bungalow, tile or composition roofs, slab in the south and raised crawlspace through the Bay Area and the north — decide what is worth doing first. California is also the one state where duct leakage is routinely tested: Title 24 requires a HERS-verified duct test on most furnace or air-conditioner changeouts, so a duct problem here often surfaces as a failed test rather than as a complaint.

Before the technician arrives

Four things worth doing — and the first one is usually the thing people get wrong.

Do not foam around a flue, a chimney or a non-airtight can light with ordinary expanding foam. Those need fire-rated sealant and proper clearance, and getting it wrong there is a genuine fire risk rather than a lost-efficiency problem.
Have the blower door result from before the work, so the after number means something.
Note where you feel drafts and at what time of day, because stack effect changes with temperature.
Do it before new attic insulation, not after. Afterwards means moving the insulation you just paid for.

What the work looks like

Photographs of air sealing being carried out, so you know what to expect on the day.

How it works

Three steps, and you decide at the end of them.

1
You call and describe the problem

Tell us what you have noticed and where — the room, the smell, the noise, how long it has been going on. Give us your ZIP code and we will match you to a licensed company covering your area. There is no form to fill in.
2
A local company takes it from there

They discuss the problem with you directly, arrange a time to inspect, and agree the work and the price with you before anything starts. That conversation is between you and them.
3
You decide whether to go ahead

You are under no obligation. If the quote or the approach is not what you wanted, you are free to say no and call someone else.

Air Sealing — FAQs

Do I actually need Air Sealing done?

Not urgent, but it is the item with the best ratio of cost to result on this whole list, and in California it does double duty: the same gaps that lose conditioned air are the ones that let wildfire smoke into the house during an event.

What does Air Sealing involve?

Closing the paths air actually moves through — top plates, penetrations, can lights, the attic hatch, rim joists — which is the half of the job insulation cannot do and the half most often left out.

What makes this different in California?

California's Mediterranean on the coast, hot and dry inland climate and its housing stock — stucco ranch and bungalow, tile or composition roofs, slab in the south and raised crawlspace through the Bay Area and the north — decide what is worth doing first. California is also the one state where duct leakage is routinely tested: Title 24 requires a HERS-verified duct test on most furnace or air-conditioner changeouts, so a duct problem here often surfaces as a failed test rather than as a complaint.

Are the companies licensed and insured?

Yes. We only pass calls to licensed, insured operators working in California, and you are welcome to ask to see a license number on arrival.

What does Air Sealing cost?

It depends on the property, the size of the system and what the inspection finds, so we do not publish a price — a figure quoted on a web page is not one the attending company has agreed to. You get a price before any work starts.

Air Sealing near you

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Call about Air Sealing

What happens when you call

Worth having to hand