How to Paint Interior Walls: Prep, Cutting In, Rolling, Two Coats

Painting the walls of a 1,500 sq ft house yourself: $722–$742 in paint, primer and a starter kit, 30–50 hours.

Before you start

Read the cost comparison first. Walls are the part of this job where DIY pays best: $732 in paint and supplies for the walls of a 1,500 sq ft house against $4,200 from a painter, and $272 against $550 for a single room. The hours are real — 5–8 for a room, 30–50 for the house — and half of them are prep, but nothing in the walls-only version needs a skill you can’t pick up in the first room.

Ceilings, trim and doors are a different project. If it’s your first time, do the walls, live with them for a month, and decide whether the trim is a second weekend or a painter’s quote.

What you need

Two gallons of wall paint per 12 × 12 room, primer for patches, a 9-inch roller frame with a 3/8-inch cover and an extension pole, a 2.5-inch angled sash brush, a tray or a bucket and grid, a putty knife and 5-in-1 tool, spackle, sanding sponges, paintable caulk, painter’s tape, canvas drop cloths and plastic sheeting, rags, and a 6-foot step ladder. The priced list is on the cost page. Buy the mid-grade paint — it covers in two coats where the cheap can takes three.

The two things that decide how it looks

The prep. Every patch you skip flashes through; every gap you didn’t caulk stays a black line; every glossy wall you didn’t scuff peels in a year. The rolling is the easy, fast, satisfying part, and the wall it goes on is what you spent the first day making.

The wet edge. Lap marks come from rolling over paint that’s already tacky. One wall at a time, cut in then roll immediately, never stop mid-wall, and always roll back into wet paint. Choose the sheen per surface before you buy, because the higher it is, the more this matters.

Step by step

1. Empty the room, or move everything to the middle

   Take down pictures, curtains and hardware; unscrew switch plates and outlet covers into a bag. Move furniture to the center and cover it with plastic; canvas drop cloths on the floor along every wall. Tape off baseboards and anything you're not painting. Open a window and set a fan.

2. Patch, sand, caulk

   Fill nail holes and dings with lightweight spackle, slightly proud; sand flush with a sanding sponge when dry. Larger holes get a patch and two coats of compound. Caulk the gap along trim and inside corners with paintable caulk and wipe it smooth. Then wipe the walls down — a damp cloth on bedrooms, a degreaser in the kitchen — and let them dry. Glossy surfaces get a scuff-sand.

3. Prime what needs it

   Spot-prime every patch and stain with a small roller or brush. Prime the whole wall for new drywall, dark-to-light changes, stains, smoke or a glossy old finish. Let it dry per the can.

4. Box the paint and set up

   Pour all the gallons of one color into a 5-gallon bucket and stir; fill a tray or hang a roller grid in the bucket. Load the sash brush a third of the way and tap, don't wipe. Roll the cover onto the frame and work it against the grid until it's evenly loaded.

5. Cut in one wall

   Brush a 2–3 inch band along the ceiling line, into the corners, around the trim and around outlets, on one wall only. Draw the brush along the edge in a long stroke with the bristles fanned; go back and feather the inside edge so it doesn't leave a ridge.

6. Roll that wall while the cut is wet

   Start a foot from the corner, roll a W about 3 feet wide from top to bottom, then fill it in with vertical passes that overlap by half a roller. Move over and repeat, always rolling back into the wet edge. Finish each section with a light top-to-bottom pass in one direction. Don't stop mid-wall.

7. Repeat for each wall, then second coat

   Cut and roll every wall, then let it dry for the can's recoat time — usually 2–4 hours. Second coat the same way. Look at the wall in raking light from a window before you call it done; a thin spot or a holiday shows now and is a five-minute fix.

8. Pull tape, reinstall, clean up

   Pull the tape at a 45-degree angle while the paint is still slightly soft; score the edge with a blade if it's fully dry. Screw the plates back on. Wash brushes and covers in warm water until it runs clear, or wrap them in plastic between coats. Pour leftover paint into a labeled quart; dry out the rest for the trash or take it to a paint drop-off.

What would this cost you? The interior painting calculator prices the DIY version with the tools you already own and a value on your time, next to a pro quote.