About Duluth Spray Foam Co.
How we approach spray foam insulation in a Climate Zone 7 town, how we price it, and the jobs we will talk you out of.
We insulate houses, cabins, and shops in one of the coldest places in the lower 48, and we do it with the assumption that the person paying for it wants to understand what they are buying.
Call (218) 514-6594.
Why we built this the way we did
If you have spent any time researching insulation online, you already know the problem. Almost everything written about spray foam was written for a general national audience, which in practice means it was written for a climate that is nothing like this one.
Advice that is fine in Ohio can cause a moisture problem in Duluth. Open cell against a roof deck is a defensible assembly in a lot of the country. Here, in Climate Zone 7, it is a way to rot your roof sheathing. R-38 in an attic is code in much of the United States. Here the number is R-49, and the newer code says R-60.
The information gap is real and it is not the homeowner’s fault. So we wrote this site the way we would explain the work standing in your basement: the actual mechanism, the actual numbers, the actual price ranges, and the parts where the honest answer is “not that, this instead.”
What we believe about this work
Air sealing matters more than R-value. Not instead of it, before it. Air moving through insulation carries far more heat than conduction through it does. A sealed R-38 attic outperforms a leaky R-60 attic. That is why the first thing we do in an attic is crawl around with a foam gun finding holes, and why “how many inches” is the second question rather than the first.
The assembly decides the material, not the other way around. People call and ask for closed cell. What they should ask is what the wall or the roof or the crawl space is supposed to do, because the right foam falls out of that. Sometimes the answer is not foam at all.
Moisture is the thing that ruins buildings. Cold costs you money. Water costs you the building. In a climate where the temperature difference across a wall is 90 degrees for months, moisture management is not a footnote to the insulation decision. It is the insulation decision.
Nobody can quote spray foam over the phone. Access, headroom, existing conditions, what has to come out, and what has to be masked all drive the number more than square footage does. A firm price given without a walkthrough is either padded or it is going to change.
Tell the customer the bad news first. Rotted sill plate behind the batts, live knob and tube in the attic, vermiculite, a wet crawl space that needs drainage before it needs foam. All of that gets said before we start, not discovered after we have covered it up.
The jobs we will talk you out of
This is probably the most useful section on the page.
Foaming a straightforward vented attic. If your attic has decent access, no mechanicals up there, and a roof that vents properly, spraying thirteen inches of foam on the floor is a poor use of your money. Air seal it with foam, which is the part foam is uniquely good at, then blow cellulose to R-60 for {{PRICE_ATTIC_R60}}. Same result, roughly a third of the cost.
A conditioned attic under a roof at the end of its life. Foam against the roof deck means a leak can travel a long way before you see it. If the shingles have five years left, reroof first, then foam.
Encapsulating a crawl space with standing water in it. That is a drainage problem. Sealing over water traps it. Sometimes the fix is a downspout extension and some grading, and we will point that out whether or not it turns into a job.
Insulating walls before the attic is done. Walls are the last dollar in an existing house, not the first. The attic and the rim joists will change how the house feels. Walls usually will not, and they cost multiples more.
A standalone small job that could ride along with a bigger one. Setup, hose, masking, and cleanup cost about the same regardless of job size. If you are going to do a crawl space next year, doing the rim joists in the same visit is meaningfully cheaper than two trips.
How we quote
- A phone call. Tell us how the building is reacting to the weather. Cold floors, ice at the eaves, a bill that hurts, a shop that drips. We will give you a realistic range on that call so you know whether to keep going.
- A walkthrough. Attic, basement, crawl space, and the mechanicals. Free, and in person, because a driveway estimate on this work is worthless.
- A written scope. What gets sealed, what gets sprayed, which product, at what thickness, what R-value that lands at, what has to come out first, what covering is required over the foam, and what it costs. If part of the job is better done with a different material, that is in the scope with its own line and its own price.
- A date. Most residential jobs are one or two days. You will need to be out of the building during the spray and for a period afterward while it cures and ventilates, typically 24 hours. You get that number in writing before the day.
Credentials and proof
Hiring anyone to work on your building is easier when you know what to ask. Here is how to check any contractor you are considering, including us:
- Ask for the Minnesota DLI license number and look it up on the Department of Labor and Industry website yourself. It takes two minutes.
- Ask for a certificate of insurance sent directly from the agent, not a PDF from the contractor. General liability and workers comp.
- Ask which product they are using and ask for the data sheet. R-value per inch, perm rating by thickness, substrate temperature range, and reoccupancy time are all on it. A contractor who cannot produce it is a contractor who does not read it.
- Ask how thick, in inches, and ask what R-value that lands at. If the answer is vague, keep calling.
- Ask about lift thickness on closed cell. The right answer is roughly two inches per pass with cooling between. Anyone promising three inches in one shot to save a day is taking a real risk with your building.
Serving the Twin Ports
Duluth, Superior, Hermantown, Proctor, Cloquet, Two Harbors, Esko, Saginaw, Rice Lake, and Carlton. Full detail on the service area page.
Call (218) 514-6594 or send the form. Leave the address and what the building is doing, and skip the part where you guess at which product you need. Working that out is our job, and it is the part of this we are actually good at.
About Duluth Spray Foam Co.: common questions
What areas do you serve?
Duluth, Superior, Hermantown, Proctor, Cloquet, Two Harbors, Esko, Saginaw, Rice Lake, and Carlton. Jobs outside that range are handled case by case, depending on size. The full list with what we know about the housing in each town is on our service area page.
Do you do free estimates?
Yes, and we do them in person. Nobody can price a spray foam job accurately without seeing the space, and a number given over the phone without questions about access and existing conditions is a guess. What we will do on the phone is give you a realistic range so you know whether to keep talking.
Will you tell me if spray foam is not the right product for my job?
Yes, and we do it regularly. The most common example is an attic. A standard vented attic with decent access does not need a foam roof assembly at $14,000 to $23,000. It needs air sealing with foam, which is a smaller job, and then blown cellulose on top of it, which costs a fraction of what foam does per unit of R-value. We would rather do the right job and be the call you make next time.
Do you handle the permit?
It depends on the jurisdiction and the scope. Insulation work as part of a larger permitted project is typically covered under that permit. Standalone insulation retrofits often are not permitted at all, though this varies by city. We will tell you what we know about your jurisdiction and we will not tell you a permit is unnecessary just to make the job easier.
What should I have ready before I call?
Roughly when the house was built, what the problem is in your own words, and which spaces are involved. Cold floors over a crawl space, ice at the eaves, a shop that drips. That is enough for a useful first conversation. Photos help. Exact measurements do not, because we will take our own.
Talk to someone about your Duluth, MN project
Call (218) 514-6594 or send the form with the details. Both arrive in the same place.