# Is Polyurethane Foam Lifting Worth It?

> Foam lifting costs $5 to $15 per sq ft against $3 to $8 for slurry. See what the premium buys and when it is the better spend.

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Last updated: 2026-11-09

Polyurethane foam lifting is worth it when the slab is on weak or wet soil, when the job has to be back in service quickly, or when the finished surface matters. At $5 to $15 per sq ft it costs roughly double a slurry lift, and the premium buys lightness, speed, and water resistance rather than a stronger slab.

## What the Premium Buys

The foam weighs 3 to 6 lb per cubic foot against about 100 lb for slurry. That matters because the soil under a settled slab has already failed once, and adding 100 lb per cubic foot to it is a gamble.

The foam cures in about 15 minutes, so a driveway or a commercial floor can be back in use the same day. It also does not absorb water, which extends the life of the lift in a wet subgrade and keeps the foam from breaking down in freeze-thaw cycles.

## The Cost Comparison

| Area | Foam at $10 | Slurry at $5 |
|---|---|---|
| 200 sq ft | $2,000 | $1,000 |
| 400 sq ft | $4,000 | $2,000 |
| 600 sq ft | $6,000 | $3,000 |

The difference is real money, and it is the reason foam is not the default on a stable site. On a stable subgrade with a shallow void, the slurry performs the same function for half the price.

## When Foam Is Worth It

Foam is worth it on organic or soft soil, where added weight would cause further settlement. It is worth it on a job with a hard deadline, such as a commercial entrance or a rental property that cannot be closed for a day.

It is worth it on an interior slab where a 1-inch hole and a visible patch would be unacceptable, because the 5/8 inch holes leave a smaller scar and the cure is fast enough to keep a room usable. And it is worth it in cold weather, where the slurry's cure depends on temperature and the foam's does not.

## When Slurry Is Worth It

Slurry is worth it on a driveway with a shallow void over compacted gravel, a sidewalk that has settled at a joint, and any job where the budget is the deciding factor and the soil is stable.

The savings are not trivial, and they compound on larger slabs. On a 400 sq ft driveway, slurry at $5 saves $2,000 against foam at $10. That money can pay for the drainage correction that keeps the void from returning, which is a better use of the budget than a lighter fill on a site that did not need one.

## The Longevity Caveat

Neither material fixes the cause. A foam lift on a slab that is still receiving roof water will fail, just more slowly than a slurry lift, because the water will wash out the soil around the foam.

The lift lasts as long as the drainage is controlled, and the foam's water resistance buys time rather than immunity. That is why the best-value quote is often the one that includes grading and downspout work, even if the lift line is higher.

## A Costed Example

A 350 sq ft garage floor with a void along one wall. Foam at $11 per sq ft:

350 × $11 = $3,850

Add drainage correction at $1,500:

Total: $5,350

The same job with slurry at $6:

350 × $6 = $2,100
Plus drainage $1,500 = $3,600

The foam costs $1,750 more. If the soil is stable, the slurry is the better value. If the soil is soft, the foam is the one that holds, and the extra $1,750 is the price of not repeating the job.

## What the Proposal Should State

A foam proposal should state the material, the density, the area, the number of injection points, and the target elevation. It should also state whether drainage correction is included and what warranty covers a re-settlement.

Ask for the manufacturer's data sheet. The compressive strength and the density are the two numbers that determine whether the foam can carry the slab, and both should be on paper rather than in a verbal assurance. A data sheet is not a marketing brochure, and the difference is obvious once you ask.

Ask what happens if the foam is over-injected, and ask whether the crew carries a grinder for the edge of a slab that ends up proud of the grade. The remedy is a second, careful lift or a grind, and the cost of either should be agreed before the crew starts rather than after the slab is 2 inches too high.

1. Confirm the slab is intact and the void is shallow.
2. Check the soil: soft or stable, wet or dry.
3. Fix the water source before the lift.
4. Get quotes for both materials on the same area.
5. Compare the total including drainage and patching.
6. Confirm the foam density and the cure schedule.

## The Verdict

Foam lifting is worth it when the conditions call for it, and it is overpriced when they do not. The honest answer depends on the soil, the schedule, and the finish, not on which material the contractor prefers to sell.

For the method detail, read [polyurethane foam lifting cost](https://foundationrepairlab.com/polyurethane-foam-lifting-cost/) and [polyurethane foam lifting problems](https://foundationrepairlab.com/polyurethane-foam-lifting-problems/). If the budget is tight and the soil is stable, [is mudjacking worth it](https://foundationrepairlab.com/mudjacking-worth-it/) covers the cheaper option.