An Edgewood homeowner emailed me four bids for a 500 square foot patio and asked why they ranged from $6,400 to $14,000 for what she assumed was the same job. It usually isn’t the same job. It’s four different guesses at a scope nobody wrote down, and comparing raw totals from that kind of process tells you almost nothing.
Write the Scope Before You Send It Out
Before three contractors ever walk the site, write one page describing what you want: dimensions, a thickness preference if you have one, what’s being removed, where drainage needs to go, and any finish or joint pattern you care about. Note the access to the site too — a narrow side yard or a steep grade changes the job for every bidder, and it should be described once rather than left for each contractor to notice or miss on their own. Hand every bidder the same page. It sounds like extra work up front, but it’s the only way three quotes end up describing the same job instead of three different jobs that happen to occupy the same patch of ground.
What a Normal Spread Looks Like
When three contractors bid the same defined scope, the totals should generally land within about 30 percent of each other. That’s a wide enough band to account for different overhead, different crew size, and different mobilization costs, without being so wide that the numbers are meaningless. A bid that comes in at roughly half the others isn’t the bargain it looks like — it almost always means something got left out, not that someone found a cheaper way to pour concrete. If two bids sit close together and a third is far outside that band in either direction, that’s the one to ask questions about before deciding anything, not the one to accept or dismiss on the number alone.
Real Differences Versus Assumed Differences
Some price gaps reflect genuine differences in the work: a thicker slab, heavier reinforcement, a deeper base section, or a harder access situation that adds mobilization and hand labor. Those are worth paying for. Other gaps come from bidders quietly assuming different things — one assumes the homeowner is hauling off debris, another assumes six inches of base where a third assumed four, one includes saw-cutting the joints and another doesn’t mention joints at all. None of that shows up in a single bottom-line number; it only shows up when every bid is broken into the same categories side by side, which is the whole argument for insisting that every bid be broken down the same way before comparing anything.
Deposits, Payment Schedules, and Leverage
A deposit in the range of 10 to 30 percent to hold a start date, with the balance tied to milestones like base approval, the pour itself, and final cleanup, is a common structure for residential flatwork; a contractor asking for the full amount up front before any material is on site is a separate conversation worth having openly, not a red flag to hide behind by itself. Ask each bidder for that schedule in writing along with the total, since a bid without one is only half the picture. What I’d caution against is waving one contractor’s low number in front of another to squeeze a discount — it rarely produces a better price, it produces a worse relationship, and a contractor who cuts a number to chase a competitor’s price is usually cutting it out of the scope, not the margin. The National Ready Mixed Concrete Association has consumer guidance on what a fair residential concrete estimate typically covers, which is a useful outside check before deciding a bid is out of line.
Once the three numbers are genuinely comparable, the decision usually comes down to method rather than price, and that is settled by what you ask each bidder before you sign — the questions that actually sort people out are a short list, and none of them is about the total.
Frequently asked questions
How much variation between bids is normal? Bids on an identical, clearly written scope commonly land within about 30 percent of one another; a much wider spread usually points to differing assumptions rather than differing prices.
Why is the lowest bid sometimes the worst choice? A bid far below the others typically excludes something the higher bids included, such as base depth, reinforcement, haul-off, or permit costs, rather than reflecting a genuinely lower price for the same scope.
Should I show one contractor a competitor’s bid? It rarely improves the outcome; a contractor asked to match a lower number usually removes scope to get there rather than lowering margin on the same job.