Learn · Project planning

What a contractor thinks about before they price your job.

When a contractor walks your job, they're doing math in their head before they hand you a number. Here's the questions they're working through — and how to work through them yourself.

A contractor's checklist (the simplified version)

• What is the actual area? Walls, floor, ceiling — in square feet, not approximated.
• What material does it need, and how much wastage is normal? Tile waste is 10%. Lumber wastage is 5-15%. Paint coverage assumes one coat.
• What's the unit of sale at the supply house? Concrete by the yard. Drywall by the sheet. Tile by the box. Paint by the gallon. You can't buy 0.7 of a bag.
• What needs to be bought together? Tile needs thinset, grout, backerboard. Drywall needs compound, tape, screws. Don't buy in three trips.
• What changes the math? Tile size changes thinset. Wall height changes drywall. Pitch changes roofing squares.