How to Compare Leveling Quotes

First: are they even quoting the same area?

This is the difference that dwarfs the others, and it is the one nobody thinks to check. One contractor prices the two panels that dropped. The other prices the whole driveway, because the panels either side are hollow underneath and will be next. Both are defensible positions and they produce very different numbers.

So before anything else, get each proposal to say in writing which slabs, panels or square footage it covers. If the two do not match, stop comparing prices — you are looking at a scope disagreement, and the useful conversation is which contractor is right about the extent rather than which is cheaper.

• Which specific panels or sections are included, marked or described unambiguously
• Whether adjacent hollow sections are in scope, excluded, or not yet assessed
• Approximate square footage or panel count, so the two documents can be laid side by side

Void filling and lifting are two operations

Raising a slab and filling the space beneath it are related but separate pieces of work, and they are not always priced the same way. Some proposals include void filling in the lift. Some price it by volume of material used, which means the final invoice is not the number on the estimate. Some do not mention it at all.

That last case is the one to watch, because a slab lifted back to elevation over a void that was never filled is sitting on the injected material alone. Ask each contractor, in the same words, how void filling is handled and whether the price can change once they see how much material the ground takes.

Two methods are not two prices for one product

If one quote is for a cementitious slurry and the other for polyurethane foam, you are not looking at two bids for the same job. The materials differ in weight, in the hole size they need, in how they behave in wet ground and in how quickly the surface returns to use, and those differences suit different sites.

Compare them on which suits your slab and your soil, and treat the price difference as a consequence of that rather than as the decision itself.

Agree what “level” means before anyone starts

Lifting a settled slab is not always a return to its original elevation. On an old slab, pushing for the last half inch can crack concrete that would have been fine an inch lower, so an experienced contractor may deliberately stop short. That is good judgement, and it is also a very different outcome from what a homeowner pictures when they read the word level.

The proposal should say what the target is: eliminating a trip lip, restoring positive drainage away from the building, or returning to original elevation. Those three are different jobs with different risks, and two contractors quoting different targets will always disagree on price.

• What the stated target elevation or outcome is, in words
• What happens if the slab will not come all the way up without cracking
• How the final result will be checked, and by whom

Holes, patching and what the surface looks like afterwards

Every injection method drills through the concrete, and the patches remain visible to some degree. Hole size differs by method, patch quality differs by contractor, and on a decorative or highly visible surface this is the part you will be looking at for years.

Ask how many holes, roughly what size, and whether patching is included and to what standard. A proposal that is silent on patching is not cheaper than one that includes it.

Whatever caused it is usually excluded

Slabs settle because something removed the support under them, and on most properties that something is water. Lifting the slab does not stop it. A downspout discharging at the slab edge, a low spot that ponds after every storm, or an uncompacted utility trench will keep working after the crew has left.

Drainage correction is nearly always outside a leveling quote. That is legitimate — it is different work — but it means the honest comparison includes what each contractor said about the cause. One who names it and excludes it in writing has told you more than one who did not mention it.

Read the guarantee for what voids it

Warranty language on leveling work varies more than almost anything else in the proposal. What matters is not the number of years but what the guarantee actually covers and what removes it. Settlement from a cause outside the work is commonly excluded, which is reasonable and is also exactly the scenario most likely to occur if the drainage was never addressed.

Get both guarantees in writing and read the exclusions before comparing the durations. A longer guarantee with wider exclusions can be the weaker one.

What to ask, in the same words, of both

The point of asking identically is that the differences in the answers are then real differences rather than differences in how you phrased the question.

• Exactly which panels or area is included in this price?
• Is void filling included, and can the price change based on material used?
• Which method are you proposing, and what about my slab or soil makes it the right one?
• What outcome are you targeting — no trip lip, drainage away from the house, or original elevation?
• How many holes, what size, and is patching included?
• What do you think caused this, and is anything about the cause in this price?
• What does the guarantee cover, and what voids it?
• What happens if the slab will not lift as expected once you start?