These are the questions homeowners actually ask us before they spend money on spray foam, answered in public, for free, with nothing to fill in first. No email gate, no PDF download, no “enter your details to see the price.” If the honest answer to your question is that you do not need us, that answer is on this site too.
We publish these because the thing people are really afraid of is not the foam. It is the installer. A bad spray foam job is expensive, it hides inside the house, and the internet will tell you (mostly correctly) that it cannot be repaired, only ripped out. So people stall for weeks. The fastest way we know to be useful is to write down what we would tell you in your driveway, including the parts that cost us the sale.
How to use this page
Every question below has a real answer attached, not just a link. Read the summary, and open the full page only if you want the detail, the numbers, and what to check on your own house. Fourteen questions, four groups, sorted by what is probably worrying you.
Worried about an install you already have
This is the biggest group for a reason. Most people who land here already have foam in the house, or a quote in hand, and something is bothering them: a smell that will not quit, a thickness that looks thin, a roof they are now nervous about. These five pages are the ones to read first.
How do I know if my spray foam was installed correctly?
If the foam is even and firm, sits at the depth you were quoted, is bonded tight to the wood, and stopped smelling within a few days, it was very probably done right. The warning signs are the mirror image: odour still hanging around weeks later, depth well under what you paid for, foam pulling away from the framing, or a texture that is crunchy, oily, or mushy instead of uniform. The page walks you through what you can check yourself with a tape measure and a flashlight.
Does spray foam insulation smell go away?
Yes, if it was mixed correctly. Properly installed foam smells during the install and through the cure period, then stops. A strong smell still in the house weeks or months later is not foam “airing out slowly,” it usually means the two chemicals went in off ratio, and that foam does not get better with time.
Can bad spray foam be removed or fixed?
It can be removed. It generally cannot be fixed in place, which is the part nobody wants to hear. Removal is mechanical, meaning scraping and cutting foam off the substrate, often in a crawl space or an attic where you cannot stand up, and it is slow and expensive. This page covers what removal actually involves and how to tell whether yours is a removal case or a live-with-it case.
Will spray foam rot my roof deck?
No. Foam is not water, and wood does not rot unless it stays wet. What foam genuinely changes is how you find out water got in at all, because a leak no longer paints a stain on your bedroom ceiling. The real rule is to deal with the roof before you insulate under it, and to understand that you are making the deck harder to inspect.
Does spray foam cause moisture problems in the Pacific Northwest?
Foam does not add moisture to a house. It changes which direction an assembly can dry, and in a marine climate like ours that is the whole conversation. The wrong product in the wrong assembly, particularly open-cell somewhere it can take on water, causes problems that fiberglass would not have caused. The right product in the right assembly solves problems fiberglass never could.
Money
Most people arrive here because of a bill, so we publish ranges rather than making you call for them. Every number on the site is a range with the variables named, because the only honest firm price is one where somebody has been under your house.
How much does spray foam insulation cost in Seattle?
Closed-cell commonly runs about $1.00 to $2.00 per board foot installed in this market, open-cell about $0.50 to $0.70. As a whole-project figure, 1,000 square feet at three inches often lands somewhere around $2,200 to $5,400. What moves it most is how many inches the assembly needs, how bad the access is, and whether old material has to come out first.
How much can spray foam actually cut my energy bill?
Nobody can give you a percentage without seeing your house, and anyone who does is selling. What we can give you is the framework the number comes from: what is up there now, how leaky the house is, how you heat it, and what you pay per unit. Run it yourself before anyone quotes you and you will know whether a bid is realistic.
Is spray foam insulation worth it in Seattle?
Often yes, for reasons specific to this climate rather than to insulation generally: mild wet winters, long heating seasons, and a lot of housing stock sitting over vented crawl spaces. But not in every house and not in every assembly. The useful half of that page is the part that tells you which one you have.
How much spray foam insulation do I need?
Foam is specified in inches, not in bags, and the inches depend on the assembly and the R-value you are targeting. Closed-cell gives roughly R-6 to R-7 per inch and open-cell roughly R-3.6 to R-4, so the same target takes very different depths. The page shows how to do the board foot math so you can check a quote against the number of inches it promises.
Choosing what to do
Three questions about picking between options, including the two where our honest answer sometimes points away from a foam job. If air sealing and blown-in will fix your house for a fraction of the price, that is what we will tell you, and we would rather you read it here than find out after you have spent the money.
Spray foam vs fiberglass batts for attics
In a vented attic with a properly sealed ceiling plane and plenty of room for depth, batts or blown-in often buy you the same comfort for far less money, and we will say so. Foam earns its price when the attic needs to come inside the thermal envelope, usually because the ducts and the air handler live up there.
Should I spray foam or encapsulate my Seattle crawl space?
These are not really competing options, they solve different halves of the problem. Encapsulation deals with ground moisture and outdoor air, insulation deals with heat loss and cold floors. In a damp Puget Sound crawl space, doing the insulation without the moisture work is how you end up paying twice.
Why are my heating bills so high even with insulation?
Usually because the house leaks air, and R-value on a leaky ceiling is a blanket with holes in it. The other common culprits are ducts running through unconditioned space and insulation that has settled, slumped, or fallen off the joists years ago. All three are findable in an afternoon, and the cheapest one is often the fix.
Practical and living with it
Two questions about what actually happens to your life around a foam job, which people are often slightly embarrassed to ask and absolutely should not be.
Do I need to leave my house during installation?
Yes, during the install and for a re-entry period afterwards. The real number depends on the product being sprayed and how much ventilation we can get into the space, so we give it to you before the day rather than as a generic figure. Anyone telling you that you can sit in the next room is not doing you a favour.
Does spray foam insulation affect selling your house?
A documented, correctly installed foam job is an asset, and a mystery foam job with no paperwork invites questions from inspectors and buyers. The practical advice is to keep the product data sheets, the thickness, and the scope in a folder from day one, whether or not you plan to move.
Still have a question we have not answered?
Ask it. There is no form to fill in first and no one will add you to a list. If it is a good question we will probably write it up as a page, which is how most of the fourteen above got here.
- Call or text (253) 766-5145. That is Paul or somebody who has been under a lot of Seattle houses. You will not get a call centre and you will not get a closer with a tablet.
- Email support@seattlesprayfoampros.com. Photos help enormously. A flashlight shot of your crawl space or attic answers more in ten seconds than a paragraph of description.
- Or book a free estimate through contact or the free estimate page. We look, we tell you what the house needs, and if that is nothing, you hear that too.
If you want the longer reads instead
The questions on this page are answers to specific worries. If you would rather understand the whole subject before you decide anything, the insulation guides are the long-form versions: the Seattle attic guide, why crawl spaces in this region get moldy, what a quality install looks like step by step, the R-value guide for climate zone 4C, and the full open-cell versus closed-cell comparison.
And if you already know what work you want done, the services pages cover what each job actually involves, what it costs here, and when we would talk you out of it.
One thing worth saying plainly, because it sits underneath every question on this page: we make our living from installs that are done correctly the first time, not from volume. That is why the failure modes are published here in detail. Nobody who cuts corners would write any of this down.