How much does spray foam insulation cost in Houston?
In Houston, open-cell spray foam generally costs $2.50 to $3.50 per square foot installed and closed-cell costs $3.50 to $5.00 per square foot. A typical attic roof deck conversion runs $4,000 to $10,000. Metal buildings and commercial work are priced by board foot against the required thickness, usually $1.50 to $2.20 per board foot for open-cell and $2.20 to $3.20 for closed-cell.
On this page
Most contractors will not put a number on a web page. We will, because you are going to get three quotes anyway and you deserve to know before the first one shows up whether it is in the right neighborhood.
The numbers below are what the Houston market actually charges, installed, as of this year. Your written quote can land outside these ranges once we see the building, and we explain why when it does.
Price per square foot in Houston
| Application | Open-cell | Closed-cell |
|---|---|---|
| Attic roof deck, existing home | $2.50 to $3.50 per sq ft | $3.50 to $5.00 per sq ft |
| Exterior walls, new construction | $2.50 to $3.25 per sq ft | $3.50 to $4.50 per sq ft |
| Crawl space or pier and beam floor | Not recommended | $3.50 to $5.00 per sq ft |
| Metal building, roof and walls | Not recommended | $2.20 to $3.20 per board foot |
| Commercial roof deck or wall | $1.50 to $2.20 per board foot | $2.20 to $3.20 per board foot |
Square foot prices assume the thickness the assembly needs to meet code, which for an attic roof deck in Houston is usually 5.5 to 7 inches of open-cell or 3 to 4 inches of closed-cell. A board foot is one square foot at one inch thick, which is how commercial and metal building work is specified and priced.
What a typical Houston attic costs
A 2,000 square foot single story house has roughly 2,400 to 2,800 square feet of roof deck once you account for pitch and overhangs. At open-cell pricing that is $6,000 to $9,800 for the foam. Two story homes have less roof per square foot of living space, so a 3,000 square foot two story often costs about the same as a 2,000 square foot single story.
Add these when they apply:
- Radiant barrier removal: $300 to $800. Foam has to bond to the deck, not a foil sheet.
- Old insulation removal: $1.00 to $2.00 per square foot of attic floor, only if it is wet, contaminated or in the way. Dry, clean insulation usually stays.
- Ignition or thermal barrier coating: $0.50 to $1.25 per square foot where code requires it over exposed foam.
- Sealing vents and fans: usually included.
That is why the honest range for a whole attic is $4,000 to $10,000, with most jobs in the $6,000 to $8,500 band. Use the cost calculator for your square footage.
What moves the price up or down
Foam type. Closed-cell costs roughly twice as much per inch but delivers nearly twice the R-value per inch, so the gap per assembly is smaller than the gap per inch. Where closed-cell is needed, it earns its cost. Where it is not, it is money you do not have to spend. The open-cell versus closed-cell post covers where each one belongs.
Access and pitch. A walkable attic with a real staircase sprays faster than a scuttle hole over a garage. Steep roofs, hips and valleys add rig time.
Prep. Roof deck condition, existing insulation, radiant barriers, wiring and recessed lights all take time before the first pass.
Size. Mobilization is a fixed cost. A 600 square foot attic costs more per square foot than a 3,000 square foot attic. Doing the garage ceiling or a shop on the same visit almost always lowers the blended rate.
Height. Metal buildings with 20 foot eaves need lifts. That is built into board foot pricing on commercial work.
Metal buildings and shops
A 30 by 40 shop with 12 foot walls has about 1,200 square feet of roof and 1,680 square feet of wall. At 1.5 inches of closed-cell, that is roughly 4,300 board feet, or $9,500 to $14,000 installed. Most owners do the roof first if budget is tight, because the roof is where the condensation and the radiant heat come from. See the metal building page for what is included.
Commercial projects
Commercial and industrial work is priced by board foot against the thickness and R-value in the specification. A 40,000 square foot warehouse roof deck at 2 inches of closed-cell is 80,000 board feet, which puts the foam alone in the $175,000 to $255,000 range before barriers, prep and phasing. We bid to the spec, itemize everything, and confirm insurance compliance in writing before we bid. Details on the commercial page.
Is spray foam worth it in Houston?
Compared with blown fiberglass at $1.00 to $1.50 per square foot on the attic floor, foam at the roof deck costs two to five times more. The difference is what it does. Blown insulation on the floor leaves your ductwork and air handler in 140 degree attic air and does nothing about air leakage. Foam brings the attic inside the envelope, air seals it in the same pass, and in a hot and humid climate the air sealing is often worth as much as the R-value.
We do not promise a percentage on your bill. Your equipment, windows, duct condition and habits are all part of the answer. What we can tell you is that the attic stops being the hottest room in the house.
Frequently asked questions
Do you charge for the estimate?
No. The home assessment is free. We look at the deck, the ducts and the mechanicals, photograph what we find, and put a scoped price in writing.
Are there rebates for spray foam in Houston?
Utility programs in the Houston area have offered attic insulation rebates in some years, and federal tax credits for insulation have come and gone. Both change often. Ask us what is available when you call and we will tell you what we know that month rather than print something here that goes stale.
Can I insulate just part of the attic?
Sometimes, but it rarely makes sense. The point of a roof deck conversion is a continuous air barrier around the whole attic. Half a sealed attic is a vented attic with expensive insulation in it. The exception is a bonus room over the garage, which can be treated as its own assembly.
Why is your quote different from the calculator?
The calculator uses square footage and foam type. The quote uses what we saw: roof area with pitch, access, prep, barriers and anything unusual. If the quote is above the range, the reason is in writing.
What to do next
Run your square footage through the calculator, then book the free assessment or text a photo of the attic to (281) 703-2700 and we will give you a ballpark from that alone.