2026 cost comparison
Pouring your own concrete slab saves 40–60% on labor — but only if you have the tools, the crew, and the skill to finish before the concrete sets. A bad DIY pour costs more to fix than hiring a pro the first time.
Below, we break down the real numbers for both paths, slab size by slab size, so you can decide with data. Run your numbers first in the concrete slab cost calculator.
20×20 ft, 4-inch slab, line by line
| Cost Item | DIY | Contractor | Notes |
|---|---|---|---|
| Concrete (5 cu yd) | $625–$875 | Included | $125–$175/cu yd delivered |
| Gravel base (4" depth) | $80–$150 | Included | ~$20–$35/ton, need ~4-5 tons |
| Rebar / wire mesh | $100–$250 | Included | 6" grid; rebar costs more than mesh |
| Form lumber | $75–$150 | Included | 2×4s + stakes + ties |
| Vapor barrier | $30–$60 | Included | 10 mil poly, ~$0.08/sq ft |
| Tool rental | $100–$250 | N/A | Mixer/float/trowel/screed for 2 days |
| Permit | $50–$300 | $50–$300 | Varies by city; same either way |
| Labor | FREE (you) | $800–$2,000 | 2-3 workers × 1 day |
| Contractor overhead & margin | N/A | $300–$800 | ~15% of total |
| TOTAL | $1,060–$2,035 | $2,400–$4,800 | |
| Per square foot | $2.65–$5.09 | $6.00–$12.00 |
The biggest line-item difference is labor — $800–$2,000 for a contractor crew vs. your own unpaid time. But notice that materials alone still run over $1,000 even if you do it yourself. Concrete is not free; you are only saving the labor and the contractor's margin.
4-inch standard slab totals
| Size | Area | DIY Total | Contractor Total | You Save |
|---|---|---|---|---|
| 10×10 | 100 sq ft | $530–$1,020 | $600–$1,200 | $70–$180 |
| 12×12 | 144 sq ft | $740–$1,420 | $864–$1,728 | $124–$308 |
| 16×16 | 256 sq ft | $1,200–$2,300 | $1,536–$3,072 | $336–$772 |
| 20×20 | 400 sq ft | $1,060–$2,035 | $2,400–$4,800 | $1,340–$2,765 |
| 20×30 | 600 sq ft | $1,550–$2,980 | $3,600–$7,200 | $2,050–$4,220 |
| 30×30 | 900 sq ft | $2,280–$4,380 | $5,400–$10,800 | $3,120–$6,420 |
| 30×40 | 1,200 sq ft | $3,020–$5,800 | $7,200–$14,400 | $4,180–$8,600 |
The pattern: DIY savings grow with slab size. On a 10×10, you barely save $70–$180 — not worth the risk. On a 30×40, you save $4,000–$8,600. That is real money, but you are also taking on a much harder pour. Compare those totals with the size price charts.
Shed bases, small patios, and walkway pads are manageable for one person with a rented mixer, and mistakes are cheap to redo.
Even helping a friend counts. Finishing concrete is a skill — you do not learn it from a video in one afternoon. If you have troweled before and know what cream means, you are ready.
The concrete truck can pull right up to the forms. No pump needed, no wheelbarrowing 5 cubic yards by hand. If a pump is required, add $400–$900 and DIY stops making financial sense.
Concrete waits for no one. Once the truck arrives, you have 60–90 minutes to place, screed, float, and trowel before the concrete starts setting.
A 20×20 pour requires about 5 cubic yards — a full concrete truck. You need at least 3 people working continuously for 90 minutes. One person alone cannot keep up.
These require precise grading for drainage, 5–6" thickness, and proper rebar placement. Code problems from improper reinforcement can void your home insurance.
Stamped, exposed aggregate, and polished surfaces are advanced techniques. Stamp tooling alone ($500–$1,200) eats most of the DIY savings.
Pouring a 20×20 slab takes 8–12 hours of hard physical labor plus 2–3 days of prep. If you would rather spend that weekend doing anything else, hire it out.
If you mess up the finish — and first-timers often do — you cannot just patch it. You rip it out and start over. A 20×20 slab redo costs $1,000+ in materials alone.
A weekend of mixer, bull float, trowels, screed, and edger rental runs $100–$250. Buying the tools outright is $400–$800. Either way, it is real money.
Demolishing and disposing of a failed 4" slab costs $200–$500 in dump fees, plus jackhammer rental ($60–$100/day) and the labor of breaking 400 sq ft of concrete.
Videos make DIY concrete look like a one-person job. It is not. For any slab over 200 sq ft, you need at least one helper to screed while you pour. Friends working for pizza are not finishers.
Concrete needs 7 days of moisture curing to reach full strength. Skip it and you get surface cracking, dusting, and a shorter lifespan. Contractors include curing; DIYers often skip it.
DIY: $530–$1,020 | Contractor: $600–$1,200. Savings: $70–$180 — barely anything. For a shed base the stakes are low: no vehicle load, no decorative finish, and if it is not perfectly flat, it sits under a shed. Decision: DIY if you want the experience. Hire it out if you value a Saturday.
DIY: $1,060–$2,035 | Contractor: $2,400–$4,800. Savings: $1,340–$2,765 — real money. But a patio is visible every day. Amateur waves or uneven edges will bother you for 30 years, and 400 sq ft is past the one-person threshold. Decision: hire a contractor. See the full patio cost guide.
DIY: $3,020–$5,800 | Contractor: $7,200–$14,400. Savings: $4,180–$8,600 — the biggest dollar spread. This is 1,200 sq ft and 10+ cubic yards. You need 4–5 people, a concrete pump (add $500–$900), perfect grading for a 40-ft run, and the stamina to finish for 2+ hours straight. Decision: hire. Full stop.
Materials alone run $3–$5/sq ft, vs $6–$12/sq ft for a contractor. So yes, DIY saves 40–60% on labor — but only if you finish correctly the first time. A failed pour that needs demo and redo costs more than hiring a pro from the start.
About 100–150 sq ft (a 10×10 or 10×12) is the max for one person with a rented mixer. Beyond that, you need at least one helper to manage the pour-and-finish window before the concrete starts setting.
A 4" slab runs $2,400–$4,800, including materials, labor, and site prep. Use our concrete slab cost calculator for a detailed estimate based on your thickness and local price.
Most cities require permits for slabs over 200 sq ft or any slab attached to a structure. Check your local building department. Permit costs range from $50–$500. Contractors typically handle permitting; if you DIY, the permit is your responsibility.
You can walk on it after 24–48 hours. Light use (patio furniture) after 7 days. Vehicles after 28 days — concrete reaches about 90% of its design strength by day 28 with proper curing.
Whether you DIY or hire, the first step is knowing what the project should cost. Plug your slab dimensions into our free concrete slab cost calculator and get a line-by-line estimate — materials, labor, site prep, and total — before you talk to any contractors.
→ Calculate My Slab Cost (Free)
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