How Much Does It Cost to Repair Foam? The Figure You Aim At, and the One You Measure

Repairing foam costs $25 to $60 in sheet stock per couch cushion and $200 to $500 per cushion at an upholstery shop; $1.50 to $4.50 per square foot to recoat a spray polyurethane foam roof and $3.50 to $7.00 per square foot where foam and coating both have to be replaced; $5 to $25 per square foot to lift a settled slab with injected structural polyurethane, which lands most residential driveway and garage-floor jobs between $1,200 and $3,600; and $1.50 to $5.00 per square foot to respray insulation foam, plus $3 to $12 per square foot if the failed foam has to be cut and scraped off first. The material and the substrate under it decide which of those numbers applies. How bad the damage looks decides almost nothing, because roofing foam, slab-lifting foam, insulation foam and cushion foam are four different products with different densities, different code requirements and different failure paths.

Which foam is it? The density spec sorts them in one line

Every one of them is quoted in pounds per cubic foot, and the number lands somewhere different for each. Roofing foam is the dense one. Gaco's application spec SPF-S20-38-20 lists its GacoRoofFoam F2733 at a nominal 2.5 to 3.0 lb/ft³, 94.3% closed cells, 50.1 psi compressive strength and an initial R-6.5 per inch; the low-GWP version runs 2.7 to 3.4 lb/ft³. The International Building Code, in the sprayed polyurethane foam roofing section (§1507.13.2), requires the material to meet ASTM C1029 Type III or IV, a denser class than what goes into an attic.

Sofa cushion foam sits at roughly a third of that weight. Carpet cushion is polyurethane too, and it is quoted at 6 to 8 lb/ft³, because rebond is shredded scrap pressed back together rather than a blown pour. Same unit, three different meanings.

| Foam system | Density spec | What actually fails | Repair figure | |---|---|---|---| | SPF roof | 2.5 to 3.4 lb/ft³, ASTM C1029 Type III or IV | topcoat weathers thin; foam wets at a breach | $1.50 to $4.50 per sq ft to recoat | | Slab-lifting polyurethane | structural grade; 90% of compressive strength in 15 minutes | soil below washed out or consolidated | $5 to $25 per sq ft | | Closed-cell insulation | medium density, roughly R-6 to R-7 per inch | debonds from substrate; open-cell holds water | $1.50 to $5.00 per sq ft to respray | | Cushion foam (HD36) | about 1.8 lb/ft³, about 36 IFD | compression set; the cushion goes flat | $25 to $60 DIY, $200 to $500 at a shop | | Carpet cushion (rebond) | 6 to 8 lb/ft³ at 7/16 in | soaks and holds water longer than the carpet | replaced, not dried |

That last row is the one I know in my hands. The first thing out of a flooded house is the pad, and it comes out because the cushion holds several times what the pile above it does. The IICRC S500 standard says the same in writing: with Category 1 clean water the carpet face can often be saved if extraction starts within 24 to 48 hours, and the pad still comes out; with Category 2 the pad always goes; with Category 3 every porous material goes.

What does foam roof repair cost, and when does a recoat do the job?

A silicone recoat costs $1.50 to $4.50 per square foot and buys you UV protection and, on most contracts, a renewed warranty. New foam plus coating over a failed area runs $3.50 to $7.00 per square foot in HomeGuide's 2026 figures, with other trade estimators quoting up to $9.50. Small patches at penetrations can be done from a kit: DAP's Touch 'n Seal 3.0 pcf product is sold specifically for repairs to existing foam roofs, and HandiFoam's high-density roof kit is rated at 340 board feet.

The measurable that decides between those two prices is film thickness. Gaco's spec applies foam at 2.0 inches plus or minus 0.25 inch, then one coat of S20 silicone at 2.5 gallons per 100 ft² to reach 40 mils wet and 38 mils dry, with a 10% variance factor added to hit minimum dry film thickness, and an optional granule coat at 0.5 gallon per 100 ft² with 30 pounds of granules broadcast per 100 ft². That system carries a 20-year labor and material warranty through the manufacturer. Cost guides put the recoat trigger near 10 mils of remaining topcoat, on a cycle of roughly 5 to 15 years depending on climate.

SPF repair against coating-only maintenance

Coating-only maintenance is the right purchase when the foam under it is dry and intact and the topcoat has simply worn down. It is the wrong purchase the moment the foam holds water, which is where a summary that lumps the two together costs a building owner real money. Silicone at 38 mils dry is a good weather seal, which means it is also a good lid. Sealing a wet assembly is the same error as laying carpet back down over a pad that still reads wet: the surface looks finished and the substrate keeps working.

The code puts a clock on the honest version of the job. IBC §1507.13.3 requires the protective coating to go on not less than 2 hours and not more than 72 hours after the foam, and §1507.13.1 requires a design slope of at least 1/4 inch per foot for drainage. Gaco's field quality control section lets the owner's representative pull core samples to verify thickness, with the applicator repairing the cut-outs at its own expense. Ask for that clause. It converts a claim into a measurement.

What does foam foundation repair cost, and when is foam the wrong tool?

Polyurethane injection for a settled slab runs $5 to $25 per square foot, or about $1,200 to $3,600 for a typical residential job, with material at roughly $6 to $7 per pound and a contractor minimum of $400 to $1,500. Injecting a leaking foundation crack is priced per crack, $400 to $1,000, against $350 to $800 for epoxy in a dry structural crack. Piering is a different order of magnitude: $1,000 to $3,000 per pier and $7,000 to $30,000 for the job, averaging near $16,000 in Angi's 2026 data.

Two published figures let you audit the bid. The first is hole spacing. TxDOT Special Specification 3229 drills 5/8 to 3/4 inch holes at roughly 3 to 4 foot intervals for soil densification and locates injection holes at 3 to 6 foot intervals for lifting and undersealing; a Central Texas Regional Mobility Authority contract spec uses 5/8 inch holes at four to six feet and requires the polyurethane to reach 90% of its compressive strength within 15 minutes. MoDOT's Engineering Policy Guide 570.5 allows 9/16 to 3/4 inch holes for polyurethane, notes that conventional mudjacking needs 2 5/8 inch holes, and specifies a pump gauge reading in 0.1-pound increments so the rate of rise can be controlled.

The second is the target. Do not write "level" on the contract. The 2010 ADA Standards §303.2 permit a vertical change in level up to 1/4 inch with no edge treatment, §303.3 requires anything between 1/4 and 1/2 inch to be beveled no steeper than 1:2, and anything above 1/2 inch has to be ramped. A quarter inch is a number a crew can hit and you can check with a straightedge.

Slab-lifting foam and insulation foam are not the same purchase

Search engines file both under "polyurethane foam injection", and the failure paths have nothing in common. Slab foam is a structural material that develops lift pressure against a load and is bid by slab area or by the pound. Insulation foam is bid by the board foot, one square foot at one inch thick, so a 2,000 ft² roof at the 2-inch thickness in the Gaco spec is 4,000 board feet, and installed pricing lands at $1.50 to $5.00 per square foot with job minimums of $1,000 to $2,000.

Insulation foam fails when the substrate wets or the foam debonds, and removal is the expensive half at $3 to $12 per square foot because cured foam has to be cut and scraped rather than vacuumed. Slab foam fails nothing; it is a response to soil that already moved. Re-injecting without correcting the downspout, the grade or the leaking service line buys the same settlement a second time.

Couch foam: which two specs decide the price?

Cushion foam is described by two numbers, both from ASTM D3574: Test A gives apparent density, and Test B1 gives indentation force deflection, the pounds of force an 8-inch disc needs to compress the sample to 25% of its original height. HD36, the common sofa-seat grade, is about 1.8 lb/ft³ at about 36 IFD. Density predicts how long the cushion lasts; IFD predicts how it feels on the first day. Ask the supplier for the support factor as well, the 65% IFD divided by the 25% IFD, since a higher ratio is what keeps a seat from bottoming out.

Sheet stock is cheap. An 82 by 24 by 1 inch HD36 sheet lists near $14 at the large mail-order foam houses, which puts $25 to $60 of raw material in a seat cushion. Cut-to-size high-resilience foam runs $100 to $300 per cushion, full reupholstery $200 to $500, and an upholsterer will open and restitch a slip-stitched seam for $15 to $30 if there is no zipper. A cushion that went flat but stayed dry needs foam and nothing else. One that got wet and stayed wet holds odor in the cover as well as the core, and replacing only the foam leaves half the problem in the room.

Before you buy foam, buy the measurement

The roofing trade has a published method for finding water under a surface, and it exists because surfaces lie. I dried a room once to the meter's satisfaction and had it sour four days later; the meter was honest about the carpet face and blind to the subfloor beneath, which is the same blindness a sound-looking topcoat gives you two inches above a wet deck. ASTM C1153 locates wet insulation by infrared imaging at night, after a day of solar gain, with no appreciable precipitation for at least 24 hours before the survey, and the standard requires invasive verification of every anomaly by cores or by cores plus probe readings. Nuclear and capacitance meters may complement that work; they may not replace it. For substrate limits, the IBC (§2303.2.9) requires fire-retardant-treated lumber dried to 19% moisture content or less and wood structural panels to 15% or less, and NRCA suggests a maximum of 75% relative humidity for lightweight structural concrete decks before roofing over them. Gaco's spec refuses application below 50°F, above 160°F, above 80% relative humidity, within 5°F of the dew point, or in wind over 15 mph, the same dew point arithmetic a drying crew watches.

A repair figure is only as good as the reading under it. The order that keeps a quote honest:

1. Identify the product and its density spec, since that decides which price sheet you are on.
2. Measure the water first: infrared with cores on a roof, meter readings into the subfloor and framing on a floor.
3. Get the failing spec in writing: remaining mils of dry film, target elevation change in inches, or density and IFD.
4. Fix the source, whether that is a breached seam, a downspout discharging at the slab, or a supply line.
5. Price the repair against the ranges above, and put the verification method in the contract.

FAQ

Can ripped foam be repaired?

Within limits. A torn cushion can be joined with contact adhesive, but the glue line stays stiff while the foam around it keeps deflecting, so replacement sheet stock at $25 to $60 per cushion usually wins. Torn roofing foam is cut back to dry foam, refoamed, then recoated.

What does foam foundation repair cost?

Polyurethane injection runs $5 to $25 per square foot, or roughly $1,200 to $3,600 for a residential slab, with contractor minimums of $400 to $1,500. Injection fills voids and lifts slabs. It does not underpin a settling footing, which needs piers at $1,000 to $3,000 each and $7,000 to $30,000 for the job.

What does foam roof repair cost?

A silicone recoat costs $1.50 to $4.50 per square foot. Replacing foam and coating over a failed section runs $3.50 to $7.00 per square foot, and small patches can be done with a 3.0 lb/ft³ roof kit. The deciding measurement is remaining dry film thickness, with recoats triggered near 10 mils.

What does it cost to repair couch foam?

Raw HD36 sheet stock costs $25 to $60 per seat cushion, cut-to-size high-resilience foam $100 to $300, and full reupholstery $200 to $500 per cushion. An upholsterer will open and restitch a non-zippered seam for $15 to $30. Match the original density and IFD, or the seat will feel wrong.

How do I tell which kind of foam I have?

Read the density. Roofing foam is 2.5 to 3.4 lb/ft³, rigid under a heel, and carries a coating. Attic insulation foam is lighter and dents with a thumb. Sofa cushion foam is near 1.8 lb/ft³ and compresses in a hand. Carpet cushion is speckled bonded scrap at 6 to 8 lb/ft³.

Should I test for moisture before paying for foam repair?

Yes, on any assembly that has been wet. An infrared survey under ASTM C1153 finds suspect areas, and the standard requires cores or probe readings to confirm them. On floors, meter the subfloor and framing rather than the surface. Coating or foaming over trapped water buys the same failure twice.