How to Paint a Room — Step by Step

Painting a room professionally comes down to thorough preparation and the right technique. Most DIY painting problems — drips, lap marks, patchy coverage — are caused by rushing the prep or skipping primer. Follow these steps and your finish will look professional.

Quick Answer

Prep → Prime → Cut in → Roll → Second coat → Trim

6 steps to a professional room paint finish

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Step 1 — Prepare the Room

Clear the room. Move all furniture out or to the centre and cover with drop cloths. Remove light switch covers, outlet covers, and all hardware from doors.

Clean the walls. Wash walls with a mild detergent solution to remove dust, grease, and grime. Let dry completely. Paint does not adhere well to dirty surfaces.

Fill all holes and cracks. Use lightweight spackle for small nail holes and drywall compound for larger repairs. Let dry, sand smooth with 120-grit sandpaper, and wipe clean.

Tape edges. Apply painter's tape to ceiling edges, baseboards, trim, and window frames. Press the tape edge down firmly with a putty knife to prevent paint bleeding underneath.

Step 2 — Prime (When Needed)

Apply primer to new drywall, bare wood, stained areas, or when making a dramatic colour change. Use a roller for large areas and a brush for edges. Allow primer to dry fully before painting — typically 3–4 hours for latex primer.

For simple repaints over a similar colour, you can skip primer and use a quality paint-and-primer-in-one for the topcoats.

Step 3 — Cut In

Cutting in means painting a 2–3 inch band of paint along all edges using an angled brush — along the ceiling line, down all corners, and along the top of baseboards and trim. Cut in the entire room before picking up the roller.

Use a quality 2–2.5 inch angled sash brush and load it to about one-third of the bristle length. Work in smooth strokes parallel to the edge you are cutting. Do not rush this step — clean cut lines define the quality of the finished job.

Step 4 — Roll the Walls

Use a 9-inch roller with a 3/8 inch nap for smooth walls, or 1/2 inch nap for light texture. Load the roller in the tray and roll off the excess until the roller is evenly coated — not dripping. Apply in a W or M pattern, filling in without lifting the roller to maintain a wet edge and avoid lap marks.

Work from the top of the wall down in overlapping sections. Complete each wall fully before moving to the next. Maintain a wet edge at all times — if the paint dries before you overlap it, you will see a lap mark.

Steps 5 & 6 — Second Coat and Trim

Step 5 — Second coat. Wait 2–4 hours after the first coat before applying the second. The second coat goes faster as the edges are already cut in. Use the same technique as the first coat.

Step 6 — Paint the trim. After the wall paint is dry, remove the wall tape and re-tape along the newly painted walls before painting trim, doors, and baseboards in semi-gloss. Remove tape while paint is still slightly tacky — pulling tape from fully dry paint can chip the wall colour.

Clean up. Wash latex paint from brushes and rollers with warm soapy water. Store leftover paint sealed tightly and labelled with the room and colour name.

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Frequently Asked Questions

What order should you paint a room?

Ceiling first, then walls, then trim and baseboards last. Always work top to bottom so drips from higher surfaces are covered by lower-surface paint.

Do you cut in before or after rolling?

Always cut in before rolling. Cut in the entire room, then roll the walls. This keeps a consistent wet edge and prevents visible overlaps between brush and roller work.

Should I remove tape before or after paint dries?

Remove tape while the paint is still slightly tacky — typically 1–2 hours after the final coat. Pulling tape from fully dry paint can lift the paint film and chip the edges.

Do I need to sand between coats of paint?

For walls — no, sanding between coats is not necessary for a good result. For trim and cabinets, a light sand with 220-grit between coats gives a smoother, higher-quality finish.

How do I avoid roller marks when painting?

Use a quality roller with the correct nap for your surface. Maintain a wet edge at all times. Apply with a W or M pattern and back-roll to even out the coat.

Should I paint the ceiling or walls first?

Always paint the ceiling first. Any drips or spatters from the ceiling roller land on the walls, which are covered when you roll the walls afterward.