Costs and decisions
How to compare concrete quotes
You have three quotes, three formats, three prices and no way to line them up.
Most homeowners compare quotes by looking at the totals. That works only if the quotes describe the same job, and in concrete work they usually do not. Which line items move the number, and by how much, is worked through job by job in the cost-factor pages.
The productive approach is to normalise the scope first — get every bidder describing the same set of items — and compare afterwards. Almost every large price gap explains itself during that process. The fastest way to do that is to put the same questions to every contractor before any of them writes a number down.
Get every quote to state the same items
For replacement, that means: area, excavation depth, base material and compacted depth, slab thickness, reinforcement type and placement, control joint spacing and depth, finish, curing method, disposal, and what is excluded.
For lifting: which panels, target elevation, method, expected material volume, what happens if more is needed, hole patching, and what the warranty covers.
For resurfacing: preparation method, crack treatment, system and thickness, number of coats, and warranty exclusions.
Ask for anything missing in writing. A contractor who will not put the specification in writing is telling you something.
Where the gaps usually are
Base preparation depth. Slab thickness. Whether disposal is included. Whether drainage work is included. Whether the apron or a transition area is included. Warranty scope. Those six items account for most large differences in residential concrete quotes.
None of them are visible in a total.
Reading the warranty rather than the length
A ten-year warranty that excludes settlement, cracking and anything caused by ground movement covers very little of what actually goes wrong. A shorter one that covers workmanship and the specific failure mode you are worried about is worth more.
Ask directly: if this settles again in two years, what happens? The answer is more informative than the headline number.
The non-price signals worth weighing
Did they look at where water goes? Did they explain what they think caused the problem? Did they mention an option that would earn them less money? Did they tell you anything you did not want to hear?
Those are the signals that separate a contractor who is diagnosing from one who is quoting.
Getting it all in one document
Ask each bidder for their quote in writing, with the specification on the same page as the price. Two separate documents — a number by email and a specification described on the phone — is how disagreements start, because there is nothing to point at afterwards.
Where a contractor is willing but disorganised, sending them your own list of the items you want stated is usually enough, and most will fill it in. That is what the estimate checklist on this site is for.
On suspiciously low bids
A bid far below the others is not automatically bad, but it is always worth understanding. The usual explanations are a thinner base, a thinner slab, no disposal, no permit, a narrower warranty, or a scope that quietly excludes part of the work.
Occasionally it is simply a contractor with lower overheads or a gap in their schedule. Ask, and see whether the answer is specific.
How we know what this page says
Each of these is something this page says. What follows is why we say it, what we had to assume, and what would change our mind — so you can weigh it rather than take it on trust. How we grade what we publish.
Two proposals for what looks like the same job frequently differ in what is actually included rather than in price for identical work.
Strong field consensus Most experienced people would say the same thing, though it rests more on accumulated field experience than on anything formally settled. You will find few practitioners who disagree, and some who qualify it.
Evidence considered
- Proposals vary in whether they include removal, disposal, base preparation, reinforcement, jointing and restoration.
- Access, protection and reinstatement are legitimate cost drivers that differ between contractors on the same site.
- The same words are used for different amounts of work across the trade.
Still to establish
- Access — you can check this yourself
- Slab thickness — partly, on your own
- Reinforcement — partly, on your own
Why we say this, and when it may not apply
It is the single most useful thing a homeowner can understand before comparing quotes, and it is the reason a comparison by total is usually a comparison of two different things.
What we had to assume
- That both proposals are for the same physical area, which is worth checking before anything else.
- That each proposal states its scope in enough detail to compare, which many do not.
When this may not apply
- Where two proposals genuinely itemise the same scope, the difference is price.
- Where one proposal is not specific enough to establish scope, there is nothing to compare yet.
What would change it
- Each proposal stating removal, base preparation, thickness, reinforcement and restoration explicitly.
- Establishing whether both are pricing the same area.
- Establishing access constraints, which affect method and cost legitimately.
Strong field consensus does not mean this: It does not mean the question is closed, and it does not mean a contractor who sees it differently is wrong or dishonest. Consensus is a description of what most people think, which is not the same as proof.
Common questions
Should I always take the middle quote?
No — that is a heuristic standing in for the work of understanding the quotes. Once the scope is normalised, the middle quote often stops being the middle one.
Is a deposit normal?
A reasonable deposit is common in this trade, particularly where materials are ordered for a specific job. A very large upfront payment before any work begins is worth questioning, and payment terms should be written down before work starts rather than agreed verbally.
Work it out, or judge the quote
Compare quotes by scope
Put two or three proposals side by side across every scope item, and see where they may not describe the same work.
Open it →Estimate decoder
Work through one proposal item by item: what it states, what is unclear, and what to ask before signing.
Open it →Estimate Comparison Checklist
Make two or three different-looking quotes genuinely comparable.
Open it →Related guides
Questions to ask a contractor
The questions that separate a diagnosis from a sales call — organised by what you are buying.
Read more →What drives replacement cost
Demolition, base, thickness and access — where the money actually goes in a repour.
Read more →What drives leveling cost
Why lifting is priced by the void rather than by the slab, and what makes two quotes differ.
Read more →Repair or replace?
The central question: when repair holds, when it is money spent twice, and how to tell.
Read more →