Deck job costing worksheet: eight stages, one margin formula

What to take away

This article gives deck and patio contractors a costing worksheet for deck jobs: the stages to cost, the inputs for each, and the formula that turns cost into a price. It uses letters, not sample prices, so you fill it with your own rates. It is not structural, engineering, building-code, permit, employment, tax, insurance or legal advice.

Footing depth, beam spans, guardrail loads and ledger attachment are set by the applicable building code. Site drainage is also set by that code and your local authority having jurisdiction. Confirm them with that office, a licensed structural engineer or the relevant regulator.

The eight deck and patio job stages you are actually pricing

Most deck and patio quotes are built as one number. The work arrives as eight stages, and each one has its own hours, its own risk and its own chance to go wrong.

Price each stage separately, then add them. A stage you cannot estimate is a stage you are guessing at, and the guess lands on your margin.

Foundation and framing: where quotes quietly lose money

Excavation is the least predictable line on a deck job. Rock, buried concrete, a high water table or a utility line all change the hours before a single board goes down.

Footing depth is set by the frost line where you build, and the frost line is published by your local building department or provincial authority. Do not carry a depth from one job to the next. Confirm the current requirement with the permit office, and have a licensed structural engineer review anything unusual.

Framing carries the same trap. Joist spacing, fastener type and hardware finish depend on the material, the span and the exposure. Coastal salt air, freeze-thaw cycles and chinook swings all change what lasts. Those choices belong to the code, the manufacturer's published instructions and an engineer, not to the estimator.

Track rework hours separately from production hours. Flashing done wrong and rot behind a ledger board rarely show up in the first season. When they do, the callback is yours and the margin is already spent.

Decking, railing and the inspection that can stop you

Decking looks like the simplest stage and hides the most waste. Board length, layout direction and the pattern you promised all set your cut waste. A run formed to the wrong length is a return trip with a trailer.

Railing is where inspection pressure lands. Guard height, post spacing and infill rules vary by jurisdiction and by how high the deck sits above grade. Name the rule source in your own notes: the building code edition your municipality enforces, plus any engineer's letter on the file.

Book the inspection before you need it. A failed inspection costs a re-inspection fee, a crew day and a schedule slip, and it usually traces back to a detail someone skipped in framing.

Building the cost map

Start with the hours, not the price. For each stage, write the labour hours, the material cost, the equipment and the subcontract cost, then add burden.

Burden is everything you pay on top of the wage: payroll taxes, workers' compensation premiums, vacation pay, and any benefits. If you do not know your own burden rate, ask your accountant or bookkeeper for the figure.

Then add the overhead that never appears on a quote:

Setting the price and the payment schedule

Build the price from the cost map, not from the last quote you lost. Decide your unit basis first: per square foot of deck surface, per linear foot of railing, or a flat stage price. Pick one and stay with it, because mixed units are how quotes stop being comparable.

Then write the payment schedule against the stages above. A deposit at contract, a draw at framing, a draw at decking, and the balance at final walkthrough is a common shape. What matters is that each draw arrives before you pay for the stage it covers.

Check your holdback and lien rules with a lawyer in your province or state before you sign anything. Those rules set when you can actually collect, and they are not the same everywhere.

Reading the numbers after the job closes

A job is not finished when the last board goes down. Close it out with four numbers per stage: estimated hours, actual hours, estimated material, actual material.

The gap between those pairs tells you which stage to reprice. If demolition always runs over, your tear-out allowance is wrong. If punch list always runs over, your handoff process is wrong.

Keep the records that support every one of those numbers. The Internal Revenue Service guidance on business records sets out the principle that income and expenses must be clearly shown and supported by documents, and the same discipline applies to your stage costing. The SBA business guide covers the planning, launch, management and growth side of the same work.

Two more sources are worth keeping on file. The Bureau of Labor Statistics wage tables publish occupation and area wage estimates you can use as one input when you review crew pay.

The FTC advertising guidance for small business explains why a claim about your work has to be truthful and supported, which matters the moment you advertise a price.

The worksheet: one deck, eight stages

Take a simple raised deck and run the arithmetic with your own figures. Each line is a worksheet row; the letters are the cells you fill with your own rates and counts.

Add the eight lines. That total is your cost. Your price is that total divided by one minus your target margin, not the total plus a percentage. Written as a formula: price = cost ÷ (1 − target margin). Adding a markup percentage to cost gives a smaller margin than the same percentage taken as margin, which is why the division matters.

Then compare the price against the deposit and draw schedule. If the first draw does not cover foundation and framing, you are financing the customer's deck.

Common questions

These are the questions contractors ask most often when they first move to stage costing.

Should I quote one price or a price per stage?

Quote one total to the customer, but build it from stage costs on your own sheet. The customer sees a clean number, and you keep the detail that tells you which stage is losing money.

How do I handle a change the customer asks for mid-build?

Define change approval before the job starts. A written change order with its own price and its own schedule effect keeps the original contract intact and stops the change from eating the original margin.

What if my area's permit rules are different from what I read here?

They probably are. Permit scope, drainage rules and inspection timing vary by municipality, and some provinces add their own contract and consumer-protection requirements. Confirm the current rules with your permit office and a lawyer before you rely on them.

Where do I start if I have never tracked stage costs?

Pick one completed job and rebuild its eight stages from receipts, timesheets and your own memory. One job gives you a baseline. The second job tells you whether the first one was typical.