What does it cost to spray foam a 2,000 square foot house in Houston?
A 2,000 square foot one story house in Houston usually has a roof deck of roughly 2,300 to 2,600 square feet once pitch, overhang and gable ends are counted, so open-cell at the deck generally runs about $5,800 to $9,100 installed. The same 2,000 square feet in a two story house is a much smaller foam job, because the attic sits over a footprint of about 1,000 square feet, and that job usually lands around $2,900 to $4,600. Nobody can quote you exactly from the floor area alone.
On this page
People call and say "my house is 2,000 square feet, what is this going to cost." It is the right question asked with the wrong number, and every contractor who answers it with a single figure is guessing at your expense.
Here is why, and here is the math we would walk you through on the phone.
Your floor area is not the area we spray
When we foam an attic, we spray the underside of the roof deck, not the floor of the attic. Those are two different sizes, and the roof is always the bigger one.
Three things make it bigger:
Pitch. A roof plane is a slope, so it covers more surface than the rectangle underneath it. On a common 6 in 12 pitch the two roof planes together come out about 12 percent larger than the footprint they cover. A steeper 8 in 12 pushes that to about 20 percent. A low slope patio roof adds almost nothing.
Overhang. Eaves extend past the walls, usually 12 to 24 inches all the way around, and that foam gets sprayed too.
Gable ends and knee walls. In an unvented attic the whole boundary has to be sealed, not just the sloped parts. A gabled roof adds two vertical triangles. A house with a bonus room adds knee walls on both sides.
Add it up and a 2,000 square foot single story house in Houston typically gives us 2,300 to 2,600 square feet of actual spray area.
The math on a one story house
Using the installed ranges we publish for this market, open-cell at $2.50 to $3.50 per square foot:
| Spray area | Open-cell installed |
|---|---|
| 2,300 sq ft | $5,750 to $8,050 |
| 2,450 sq ft | $6,125 to $8,575 |
| 2,600 sq ft | $6,500 to $9,100 |
So the honest answer for a 2,000 square foot one story Houston house is roughly $5,800 to $9,100, and where you land inside that depends on the things in the next section.
That sits inside the $4,000 to $10,000 band we quote for a typical attic, which is the number you will see on our cost page and in our calculator.
The math on a two story house
This is the part that surprises people. A two story house is a cheaper foam job than a one story house of the same size.
Two thousand square feet split over two floors means the attic only sits on about 1,000 square feet of footprint. Add pitch, overhang and gable ends and you are spraying roughly 1,150 to 1,300 square feet, which comes out around $2,900 to $4,600 in open-cell.
The upstairs is usually the hot part of the house, so the people who need this most often pay the least for it. If you got quoted the same price as your one story neighbor, ask why.
What moves the number inside the range
Square footage sets the neighborhood. These set the exact figure:
Thickness, which comes from code. Greater Houston is in Climate Zone 2A. Depending on which code edition your city or county enforces, the attic minimum is R-38 or R-49, and that decides whether we are spraying 5.5 inches or closer to 7 of open-cell. More inches, more material, higher price. We confirm the adopted edition with the permitting authority before we quote, and we wrote the whole thing up in what R-value Houston code requires.
Removing what is up there now. Blown-in fiberglass or cellulose on the attic floor has to come out before the deck gets sprayed. That is labor, bags and a vacuum truck, and on a full attic it is a real line item.
Access. A pull-down stair in a hallway is easy. A small scuttle hole in a closet, a two story roof line, or 14 foot ceilings under the attic all slow the crew down and cost more.
What is in the way. Ductwork, an air handler, storage decking and recessed can lights all have to be worked around or temporarily moved.
Deck condition. We do not spray over a wet or unsound substrate. If there is an active leak or rotten decking, that gets fixed first, by your roofer or by us if it is small.
Gas appliances in the attic. Sealing an attic changes where a furnace or water heater gets its combustion air. If you have atmospheric vented equipment up there, that has to be checked and sometimes addressed. It is not always an extra cost, but it is always a conversation, and a contractor who does not raise it is not paying attention.
Open-cell or closed-cell changes everything
The figures above are open-cell, which is the usual choice for a Houston attic roof deck. Closed-cell runs $3.50 to $5.00 per square foot installed, so the same one story house lands closer to $8,000 to $13,000.
For most attics here, that extra cost buys you something you do not need. Closed-cell earns its price in crawl spaces, on metal buildings and in coastal and wind exposed assemblies. We go through it assembly by assembly in open-cell or closed-cell for a Houston home.
What the range does not include
Our written proposal names the product, the installed thickness, the R-value it achieves and the area covered, so you can compare it line by line against anyone else's. What is not in the number above: roof repairs, electrical work, adding or relocating HVAC equipment, and drywall or paint if a ceiling has to be opened. If any of that applies we say so in the proposal instead of discovering it on install day.
The short version
Give a contractor your floor area and you will get a guess. Give them the roof deck area, the pitch, what is in the attic now and how you get up there, and you can get a real number.
Or move the slider on our calculator for a ballpark in ten seconds, then let us come look at the attic and put a scoped price in writing. The assessment is free, most attics are one day of work, and if your house is not a good candidate we will tell you that instead of selling you foam.