Deck coating looks like the simplest thing a waterproofing contractor prices: square feet times a number. That's exactly why it's where margins quietly die. The data sheet gives you a theoretical coverage rate; the job gives you a broom-finished slab, a pour that wandered a quarter inch, and pails that don't divide evenly into your field area. Here's how to price it like it will actually go.
Coverage rates: theoretical vs. yours
A data sheet coverage rate is measured on an ideal substrate at an ideal thickness. Your effective rate depends on:
- Substrate texture. A heavy broom finish can drink 15–25% more base coat than a steel trowel finish.
- Coat structure. A pedestrian system might be primer + base + texture + top; a vehicular system adds coats and aggregate broadcast. Each coat has its own rate — price them separately, never as a blended number.
- Your crews. Track what your foremen actually achieve per system. After a few jobs, your historical rate beats any data sheet.
Packaging: you buy pails, not gallons
If a coat needs 27.4 gallons and the product ships in 5-gallon pails, you're buying six pails — and the seventh when the substrate drinks more than planned. Estimate at the packaging level: round each coat's material up to purchasable units, then apply waste. Doing this per coat instead of per system is the difference between a real material cost and a hopeful one.
Waste is not one number
Flat field area on a big open deck might run 5% waste. Now add:
- Perimeter details, drains, and posts — detail work wastes disproportionally.
- Cut-up geometry: balconies waste more than podiums.
- Aggregate broadcast: you reclaim some, you sweep off plenty.
Set waste per coat and per condition, and let small, cut-up areas carry a higher factor than open field.
Labor: production rates by coat and condition
Labor is where deck coating bids are won honestly or lost invisibly. Build production rates per operation — prep, priming, base, texture, top coat, detail work — and adjust for:
- Prep intensity. Shot blast vs. grind vs. acid etch are different days.
- Access and staging. Occupied balconies with material going up an elevator are not a podium with a boom forklift.
- Recoat windows. A system with 12-hour recoat windows dictates your crew's day whether you like it or not.
- Mobilizations. Phased pours or occupied buildings mean multiple move-ons. Price each one deliberately — they are real hours and real money.
The moisture question
Half of deck coating disputes trace back to substrate moisture. Decide at bid time: is moisture testing included? Is a moisture-mitigating primer an add alternate? Say it in the proposal's inclusions/exclusions — an alternate priced up front beats a change-order argument after the blisters show up.
Put it in a system, not a memory
Every rule above — per-coat coverage, packaging round-up, condition-based waste, production rates, mobilization pricing — is exactly the logic that belongs in an estimating worksheet, not in an estimator's head at 9 PM on bid night. That's what Division 7 Estimating's brand-specific worksheets encode, with your rates and your margins. See it on one of your decks — or send us the plans and we'll price it with you.