Flooring & Walls

Count strips, not square feet. Here is the decorator’s method for working out wallpaper rolls, how pattern repeat changes it, and a strips-per-roll chart.

A 12 × 12 ft room with 8 ft walls needs 14 sheets of 4 × 8 drywall for the walls, or 19 with the ceiling. Here is the formula, a chart and material estimates.

A 12 × 12 ft room with 8 ft walls needs about 2 gallons of paint for two coats. Here is the formula, a chart for common room sizes and coverage tips.

Divide the area by the area of one tile plus its grout joint, then add 10–15% for cuts. Worked examples for a bathroom floor, a tub surround and a backsplash.

Measure the length and width of each rectangle, add the areas, add 10% for waste and divide by the box coverage. Here is how to handle L-shaped rooms and closets.