Do it yourself concrete swimming pool?

Typical thickness

4 inchespool deck

Typical strength

4ASTM C39 at 28 days

Quotes

get 3compare scope, not just price

Licensing

state or cityno national register

Short version

• Concrete licensing is regulated at state or city level and there is no national register — California has a C-8 concrete specialty licence, Texas has no statewide contractor licence at all.
• A quote should state slab thickness, base depth and material, reinforcement, joint spacing, mix strength and finish. One that states only a square-foot price is not comparable to one that does.
• Verify insurance by calling the carrier, not by accepting a certificate — certificates are easy to produce and easy to have lapsed.
• Partial deposits are normal; paying in full before work begins is not, and removes your only leverage.
• Ask to see finished work two or three years old rather than last month’s. Concrete problems surface with time.

How do you compare concrete quotes fairly?

Compare scope before price, because the cheapest bid is often cheap for a reason you can see in the specification. A quote should state the slab thickness, the depth and type of base material, whether the base is compacted, the reinforcement, the joint spacing, the mix strength in psi, and the finish. Two bids on the same patio can differ by thousands purely because one is a 4-inch slab on 4 inches of compacted base and the other is a 3.5-inch slab poured on graded dirt.

Ask each contractor to quote the same specification. If one has proposed something different — a thicker slab, a different reinforcement approach — ask why, because sometimes the higher bid is the one that read the site correctly. Get the specification in writing before work starts. A verbal agreement about thickness is unprovable once the concrete is down.

How do you check a concrete contractor is licensed?

Go to the licensing authority directly, because there is no national register and the requirements themselves differ. California licenses concrete work as a C-8 specialty through the Contractors State License Board. Nevada licenses through the State Contractors Board, Louisiana through the LSLBC. Texas has no statewide contractor licence at all, and Illinois has none either — licensing there is municipal, so Rock Island requires a concrete flatwork licence while Chicago requires a mason licence.

That variation is why a contractor saying they are licensed means little until you check what they are licensed for and whether it is current. Look up the licence number on the issuing board’s own site rather than accepting a card or a certificate. The board will also show any disciplinary history, and whether the bond and insurance the licence requires are actually in force.

What should the payment schedule look like?

A partial deposit at the start, progress payments tied to milestones, and a final payment after the work is complete and you have inspected it. What that deposit should be varies by market and by job size, but paying the full contract amount before any work begins removes every piece of leverage you have and is the common feature of the worst outcomes.

Tie the final payment to something observable: the slab poured, finished, jointed, cured and cleaned up, with the site left as agreed. Hold it until you have walked the work. And be wary of pressure to pay in cash for a discount — it usually signals the job is not going through the books, which tends to correlate with no licence, no insurance, and no recourse if the slab fails in two years.

Common mistakes

• Comparing quotes on total price alone — thickness, base preparation, reinforcement and jointing are where bids actually differ
• Accepting a certificate of insurance at face value — certificates are easy to produce and easy to have lapsed — confirm with the carrier
• Paying in full before work starts — it removes your only leverage, and is the common feature of the worst outcomes