How to Prep a Room for Painting Like a Pro (Step-by-Step)

Step 1: Clear and Protect the Space

Start by removing everything you can from the room. Pictures, curtains, and small furniture should go completely. For heavy furniture, move everything to the center and cover with plastic sheeting.

Lay canvas drop cloths on the floor. Canvas absorbs drips better than plastic and won’t slip under your feet. Protect baseboards with painter’s tape if you’re not painting them.

Pro Tip: Remove outlet covers, light switch plates, and HVAC vent covers. Put the screws back in the outlets so you don’t lose them. This takes 10 minutes but saves you 30 minutes of careful cutting around each fixture.

Time Estimate: 30-45 minutes for a standard bedroom.

Step 2: Inspect Your Walls for Damage

Walk around with a bright LED work light held at an angle to the wall. This technique (called rake lighting) reveals every imperfection. Look for:

• Nail holes and dents
• Cracks in drywall or plaster
• Loose or peeling paint
• Water stains or discoloration
• Mold or mildew (common in bathrooms and basements)

Mark problem spots with painter’s tape so you don’t miss them during repairs.

Common Issue: Many homes built before 1978 have lead paint. If your paint is chipping and your home is older, get a $5 lead test kit from the hardware store before sanding. Lead dust is dangerous, especially for kids and pregnant women.

Step 3: Clean Your Walls Thoroughly

This step matters more than most people think. Paint won’t stick to greasy or dusty surfaces. Here’s how to clean different rooms:

• Regular Rooms (Bedrooms, Living Rooms): Mix warm water with a few drops of dish soap. Wipe walls with a damp sponge from top to bottom. Rinse with clean water and let dry for 2-3 hours.
• Kitchens: Kitchen walls collect grease film you can’t always see. Use a grease-cutting cleaner or mix 1/4 cup TSP with a gallon of warm water. Wear gloves because TSP is harsh. Scrub gently, rinse twice, and dry completely.
• Bathrooms: Check for mildew in corners and near the ceiling. Never paint over mildew. Mix 3 parts water to 1 part bleach, apply with a sponge, let sit for 5 minutes, scrub with a soft brush, and rinse well. Wear gloves and open windows for ventilation.
• Smoke Damage: If previous owners smoked, you’ll see yellow-brown stains. Regular cleaning won’t remove nicotine residue. Use a strong degreaser or TSP, then prime with a stain-blocking primer like Kilz or BIN shellac-based primer.
• Critical Rule: Walls must be completely dry before you paint. Painting damp walls causes blistering and peeling within weeks.
  
  

Step 4: Repair Holes and Cracks

Small nail holes need a lightweight spackle. Apply with a putty knife, overfill slightly, and let dry for 1-2 hours. Larger holes need multiple thin coats of joint compound.

For cracks, use a putty knife to scrape out any loose material first. Fill with spackle or joint compound and smooth flat with the wall. Let each coat dry before adding more.

Wood Trim Repairs: Use wood filler for baseboards and door frames. It’s different from spackle and designed for wood surfaces.

Drywall Tips:

• Don’t pile on thick layers. Multiple thin coats work better.
• Let repairs dry overnight if possible. Rushing causes cracks.
• Slightly overfill holes because the compound shrinks as it dries.
  
  

Step 5: Sand All Repaired Areas

Once repairs are dry, sand them smooth with 220-grit sandpaper. The goal is making repairs invisible by feathering the edges into the surrounding wall.

For previously painted glossy surfaces, lightly sand with 120-grit sandpaper. This dulls the shine and gives new paint something to grip. You don’t need to remove old paint, just rough up the surface.

Textured Walls: Skip sanding if your walls have knockdown or orange peel texture. You’ll damage the pattern.

Wipe down sanded areas with a damp cloth to remove dust. Better yet, use a tack cloth (a sticky rag that grabs dust particles).

Step 6: Caulk Gaps and Seams

This step separates DIY jobs from professional results. Caulk the gaps where baseboards meet walls, around door frames, and along crown molding.

Caulking Tips:

• Cut the caulk tube tip smaller than you think you need. You can always make it bigger.
• Apply smooth, continuous beads. Don’t stop and start.
• Keep a bowl of soapy water nearby. Dip your finger in it and smooth the caulk immediately after applying.
• Use a paintable latex caulk. Silicone caulk won’t accept paint.
  
  

This takes practice. Your first attempt might look messy, but you’ll improve quickly.

Step 7: Mask Off Trim and Edges

Apply painter’s tape along baseboards, door frames, and ceiling edges. Press it down firmly with a putty knife to prevent paint from bleeding underneath.

Taping Strategy: Some painters skip this and “cut in” freehand with a brush. That requires a steady hand and years of practice. For your first few rooms, use tape.

Leave a tiny gap between the tape and the edge you’re painting. This prevents accidentally pulling off dried paint when you remove the tape later.

Step 8: Prime Your Walls

Primer isn’t optional. It serves three purposes:

1. Seals porous surfaces so paint doesn’t soak in unevenly
2. Covers stains and color changes
3. Helps paint adhere properly

When to Prime:

• Always prime new drywall
• Prime all repaired spots (spackle and joint compound are porous)
• Prime when changing from dark to light colors
• Prime stained areas (water marks, smoke damage)
• Prime glossy surfaces after sanding
  
  

Room-Specific Primer Tips:

• Fresh Plaster or New Drywall: Use a high-quality drywall primer or make a “mist coat” by thinning your finish paint with 30% water. Apply this first coat, let dry 2-3 hours, then apply two coats of regular paint.
• Glossy or Semi-Gloss Surfaces: Sand well, then use a bonding primer like Zinsser Bulls Eye 1-2-3. Regular primers struggle to stick to shiny surfaces.
• Stained or Damaged Walls: Use a stain-blocking primer. Kilz Original or BIN shellac-based primer seals water stains, smoke damage, and prevents bleed-through.
  
  

Let the primer dry according to the can’s instructions. Usually 2-4 hours, but overnight is better if you can wait.

Step 9: Final Check Before Painting

Walk around with your work light again. Check for:

• Missed holes or cracks
• Dust on surfaces
• Gaps that need caulking
• Loose painter’s tape
  
  

Fix anything you find now. It’s much easier than fixing it after you’ve already painted.