Most people who call us have already spent two or three weeks reading. They know roughly what R-value means, they half understand closed-cell versus open-cell, and they still cannot tell whether the quote in their inbox is a fair one. These six guides are written to close that gap. They are the long-form version of what Paul would tell you standing in your driveway, with the numbers left in.
We publish this for a straightforward reason. The thing that stops a Seattle homeowner from buying insulation is not price, it is the fear of paying for work they cannot inspect and cannot undo. The only honest way to fix that is to explain how the work is actually done, including the ways it gets done badly. Nobody who cuts corners would publish a page like what a quality spray foam install looks like. That is rather the point.
Read as much or as little as you want. Nothing here is gated, nothing asks for your email, and if the guides lead you to the conclusion that you do not need spray foam, we would honestly rather you got there on your own page than after a sales visit.
Start with your house
Before you compare products, work out what your house is actually doing wrong. In this region it is nearly always one of two places: the attic, where the heat leaves, or the crawl space, where the damp and the cold floors come from. These two guides are the ones to read first.
The Seattle Homeowner’s Guide to Attic Insulation
How to read what is already up there, how much depth a Seattle attic actually needs, and why sealing the ceiling before you add insulation changes the result more than the insulation does. Covers vented attics, conditioned attics, and the bonus room over the garage that never gets warm.
For anyone whose upstairs is cold in January or whose winter bill jumped and stayed up.
Read the guideWhy Seattle Crawl Spaces Get Moldy, and What Actually Fixes Them
Puget Sound crawl spaces fail for a different reason than the ones in Texas or Georgia, which is why most of the advice online does not transfer. This walks through the dew point mechanism, why the vents dry nothing here, and the order the repairs have to happen in.
For anyone who just had an inspector, a plumber, or a pest company tell them the insulation under the house is soaked.
Read the guideThen understand the products
Once you know which part of the house is the problem, the next question is what goes in it and how much. These two guides cover the material choice and the number that material has to hit, both written for our climate zone rather than a national average.
Open-Cell vs Closed-Cell Spray Foam
The cell structure drives every other difference: R-value per inch, whether the foam handles moisture, whether it adds stiffness, and what it costs. This guide puts the two side by side and says which assemblies in a Puget Sound house belong to which product.
For anyone holding two quotes that name different foams, or anyone who wants to work out which one is already in their house.
Read the guideR-Value Guide for Seattle Homes (Climate Zone 4C Marine)
What R-value is, what it is not, and the depths that actually make sense for attics, floors, walls, and crawl space perimeters in zone 4C marine. Includes the arithmetic for converting inches of foam into R-value so you can check a quote yourself.
For anyone comparing bids by the numbers, or wondering whether more inches is still buying them anything.
Read the guideAnd know what good work looks like
This is the part of the library we care about most, because it is the part nobody else publishes. A bad foam job generally cannot be repaired, only removed, so the install is the product. These two guides cover judging the work and judging what is already in the house.
What a Quality Spray Foam Install Looks Like
Substrate temperature, mix ratio, pass thickness, and cure. Those four variables decide whether your foam is worth what you paid, and all four are invisible once the drywall goes back on. This guide explains each one in plain language and lists what to ask a contractor before the truck shows up.
For anyone about to hire someone, and for anyone who wants to know what the horror stories actually have in common.
Read the guideWhen to Replace Old Insulation
Settled blown-in, flattened batts, rodent damage, and material that has been quietly wet for years all behave differently, and only some of them justify the cost of removal. This guide gives you the tests, including the ones you can run yourself with a flashlight and a tape measure.
For anyone deciding whether to pull the old material out or add over the top of it.
Read the guideWhere to start, based on what sent you here
Most people arrive with one specific complaint rather than a general interest in building science. If that is you, start at the row that matches your symptom and ignore the rest of the library until later.
| What sent you here | What it usually turns out to be | Start with |
|---|---|---|
| The winter bill jumped and never came back down | A thin, unsealed attic doing very little | The attic insulation guide |
| The floors are cold from October to April | Fallen floor insulation, open rim joists, vented crawl space | The crawl space guide |
| Somebody said your crawl space is wet or moldy | Ground moisture and dew point, not usually a leak | The crawl space guide |
| You have two quotes naming different foams | A real material decision, sometimes a substitution | Open-cell vs closed-cell |
| A quote lists inches and you want to check the math | A fair question that nobody should dodge | The R-value guide |
| You already have foam and something feels wrong | Worth checking properly rather than worrying | How to tell if it was installed correctly |
| The old material up there looks bad | Sometimes removal, often not | When to replace old insulation |
Have one specific question instead?
The guides are long because the subjects are. If you came in with a single question, the short answers live on the other side of the library. Head to the questions hub for straight answers on cost, smell, roof decks, resale, whether you need to leave the house during the install, and whether any of this is worth it in Seattle.
How to use the library without wasting your evening
You do not need to read all six. In practice the useful path is short.
Find your symptom
Use the table above. One guide is almost always enough to explain what your house is doing.
Look at the assembly
Get a flashlight into the attic hatch or the crawl space door. Ten minutes of looking beats an hour of reading.
Read the product guide
Only once you know which part of the house you are treating. Otherwise you are shopping before you have a problem.
Check the quotes
Bring the install-quality guide to the bids you get, including ours. Ask the awkward questions of everyone.
When you want a real number for your house rather than a range, that is what the free estimate is for. Somebody has to actually look at the assembly, and no honest quote gets written over the phone. If you would rather know who you would be dealing with first, here is Paul and what 15 years of this work has taught him. If you already know what you want done, the services pages cover each job in detail.
Questions about the library itself
Do you charge for advice, or is any of this gated?
No, and no. Every guide on this site is free to read, none of them ask for your email address, and there is no download form in front of anything. The reason is practical rather than generous: homeowners who understand the work make better decisions, ask better questions, and are far less likely to hire a crew that will do damage. We would rather compete against an informed buyer.
Will you tell me if I do not need spray foam?
Yes, and it happens regularly. In plenty of Seattle houses the honest answer is a few hundred dollars of air sealing, or blown-in over a properly sealed ceiling, rather than a foam job costing several times that. Several of these guides say so directly. If we look at your house and the cheaper fix is the right one, that is what you will hear, in writing, with the reasoning.
Can I call with a question if I am not ready to hire anyone?
You can. The number is (253) 766-5145 and Paul is usually the person who picks it up. People call to ask what they are looking at in their crawl space, or to read a quote from another company out loud and ask whether it makes sense. That is a fine use of a phone call. You will not get added to a follow-up list for it.
Who writes these guides?
They come out of Paul Kohn’s 15 years of spray foam work in this climate, including a fair amount of removing other people’s failed installs. The numbers in them are the numbers we quote from, and the failure modes described are ones we have actually stood in. Where something depends on the specific product or the specific house, the guides say so rather than giving you a rule of thumb that does not hold.
How often does the library change?
We add and revise as the work teaches us something new or as a price range genuinely moves. Cost figures on this site are ranges for the Seattle and Puget Sound market rather than fixed prices, because access, depth, and whether old material has to come out move the total more than anything else. If a number here ever looks stale next to a quote you are holding, call and ask about it.