How Much Paint Does a Deck Need?
Deck paint coverage varies based on wood condition and type. New smooth wood allows approximately 300 to 400 sq ft per gallon. Weathered, rough, or porous wood absorbs 30 to 50% more paint, reducing coverage to 200 to 250 sq ft per gallon.
A 300 sq ft deck needs about 1 gallon per coat on smooth wood, or 1.5 gallons per coat on weathered wood. For two coats, budget 2 gallons on smooth wood or 3 gallons on weathered wood.
Railings, stairs, and vertical surfaces require significantly more paint per square foot than horizontal deck boards. Always add 1 gallon for railings and stairs when calculating total paint needed.
Deck Paint — Reference Table
| Deck Size | 1 Coat | 2 Coats | Litres (2 coats) |
|---|---|---|---|
| 200 sq ft deck | ~0.6 gal | ~1.2 gal | ~4.5 litres |
| 300 sq ft deck | ~0.9 gal | ~1.75 gal | ~6.6 litres |
| 400 sq ft deck | ~1.2 gal | ~2.3 gal | ~8.7 litres |
| 500 sq ft deck | ~1.5 gal | ~3 gal | ~11.4 litres |
| Railings + stairs (add) | +0.5 gal | +1 gal | +3.8 litres |
Deck Paint vs Deck Stain
Deck stain penetrates the wood and cannot peel or blister. It is the lower-maintenance option and easier to reapply — simply clean and apply a new coat every 2 to 4 years without stripping. Paint sits on the surface and provides better colour coverage and opacity, but it will eventually peel and requires stripping before recoating.
For a new deck, stain or a penetrating oil finish is often the better long-term choice. For an existing painted deck, repainting in a deck-specific coating is usually more practical than stripping to bare wood.
Tips for Painting a Deck
Power wash and allow 48 hours drying time before painting — painting over damp wood leads to poor adhesion and early peeling.
Sand rough or splintered boards before painting — this improves adhesion and gives a smoother finish underfoot.
Apply with a brush on the first coat to work paint into the wood grain, then roll subsequent coats for speed.
Apply in mild, dry weather — avoid painting in direct sunlight (paint dries too fast) or when temperatures drop below 50°F overnight.
Allow 48 hours before light foot traffic and at least 7 days before replacing outdoor furniture.
Related Paint Calculators
- Deck Paint Calculator →
- Deck Stain Calculator →
- How Much Paint for a Fence? →
- Stain Calculator →
- Exterior Paint Calculator →
- Spray Paint Calculator →
- Free Paint Calculator →
Frequently Asked Questions
How much paint do I need for a deck?
A 300 sq ft deck needs about 1.75 gallons for two coats on smooth wood. Add 1 gallon for railings and stairs, giving a total of about 2.75 gallons.
Should I paint or stain my deck?
Stain is lower maintenance and lasts longer without peeling. Paint gives better colour coverage. For a new deck, stain is usually the better long-term choice.
How many coats of paint on a deck?
Two coats are standard. For bare or stripped decks, one coat of primer plus two topcoats gives the best adhesion and durability.
How long does deck paint last?
Quality deck paint lasts 3 to 5 years with proper prep. Deck stain lasts 2 to 4 years. Both last longer when applied over properly prepared surfaces.
Do I need primer on a deck?
New or stripped decks benefit from a wood primer or deck primer. Many deck paints are self-priming — check the manufacturer instructions before buying separate primer.
How long after painting a deck can I use it?
Deck paint is safe to walk on within 24 to 48 hours. Allow 7 days before replacing heavy furniture. Avoid power washing for at least 30 days after painting.