Painting2025-11-05

When You Need Primer: Drywall, Wood & Bare Surface Guide

Industry guidelines on primer requirements with no marketing BS.

Do I Need Primer?

YES - Always prime: New drywall, bare wood, stains, or dramatic color changes

MAYBE - Prime if: Patched areas, glossy surfaces, or questionable existing paint

NO - Skip primer: Good condition painted walls, same color/sheen, quality paint-and-primer combo

Situations Requiring Primer

REQUIREDNew Drywall

Bare drywall and joint compound are highly porous and absorb paint unevenly. Always prime new drywall.

Use:

  • • PVA (polyvinyl acetate) drywall primer
  • • Coverage: 300-400 sq ft per gallon
  • • Dry time: 2-4 hours

REQUIREDBare Wood

Wood tannins bleed through paint. Knots and sap require blocking. Always prime bare wood.

Use:

  • • Oil-based primer for knots and resinous wood
  • • Shellac-based primer for severe stains
  • • Coverage: 200-300 sq ft per gallon on raw wood

REQUIREDStains & Water Damage

Water stains, smoke damage, crayon, permanent marker - these bleed through regular paint.

Use:

  • • Shellac-based stain blocker (best performance)
  • • Oil-based stain blocker (good alternative)
  • • 2 coats may be needed for severe stains

REQUIREDDramatic Color Changes

Going from dark colors to light (or vice versa) requires tinted primer to minimize coats.

Rule of Thumb:

  • • Dark to light: Tint primer to 50% of final color
  • • Light to dark: Use gray-tinted primer
  • • Saves 1-2 coats of expensive finish paint

When Primer Might Not Be Needed

OPTIONALPreviously Painted Walls in Good Condition

If existing paint is sound, similar color, and similar sheen - primer is optional with quality paint.

Requirements:

  • • Existing paint not peeling or chalking
  • • No stains or repairs
  • • Similar color (within 2-3 shades)
  • • Using premium "paint and primer in one"

SPOT-PRIMEPatched or Repaired Areas

Spackle and joint compound are porous - prime patches even if not priming entire wall.

Spot-Priming Process:

  • • Prime only repaired areas with PVA primer
  • • Let dry completely (1-2 hours)
  • • Then paint entire wall with finish coat
  • • Prevents "flashing" (dull spots)

The Truth About "Paint & Primer in One"

"Paint and primer in one" products are just thicker paint. They work in limited situations.

When They Work

  • • Repainting similar colors
  • • Previously painted, sound surfaces
  • • Minor touch-ups
  • • Good condition walls

When They Don't

  • • New drywall
  • • Bare wood
  • • Stains or water damage
  • • Dramatic color changes

Industry Reality: "Paint and primer in one" is primarily a marketing term. These are simply higher-solids paints. They can't block stains, seal porous surfaces, or provide adhesion like dedicated primers.

Primer Types & Applications

Primer TypeBest ForDry Time
PVA Drywall Primer
Water-based
New drywall, joint compound, plaster2-4 hours
Oil-Based Primer
Alkyd/Oil
Bare wood, stains, glossy surfaces6-8 hours
Shellac Primer
Alcohol-based
Severe stains, smoke, water damage45-60 minutes
Bonding Primer
Water-based
Glossy surfaces, tile, laminate2-4 hours