How to Stain a Deck

Deck staining is the single most important maintenance task for a wood deck - and one of the most commonly done wrong. Stain applied to a dirty or previously failed surface fails just as fast as the old finish. Prep is 80% of the job.

Step 1: Calculate Stain Needed

Use the Deck Stain Calculator - enter deck square footage, number of coats, railing factor, and wood condition. New smooth wood covers at 175-200 sq ft/gal while weathered wood may only cover 100 sq ft/gal on the first coat. Always buy one extra gallon as a buffer.

Step 2: Do the Water Test

Sprinkle water on the deck surface. If it beads up, the existing stain is still working - a maintenance coat is sufficient. If water soaks in immediately, the finish has failed and you need a full clean and recoat.

Step 3: Clean the Deck

Use a deck cleaner or brightener to remove gray oxidation, mildew, tannin stains, and old finish residue. Apply with a brush, let sit 15-20 minutes, then rinse thoroughly. A wood brightener restores natural color and opens the grain for better stain absorption.

Step 4: Strip Failing Stain if Needed

If the existing stain is peeling or flaking, stripping is required before recoating. Apply deck stripper per label directions, let dwell, scrub, and rinse. After stripping, use a brightener to neutralize stripping chemicals.

Step 5: Sand if Needed

After cleaning, sand with 60-80 grit sandpaper if there's significant raised grain or remaining finish residue. Always sand with the grain. Vacuum and blow out dust from between boards before staining.

Step 6: Apply the Stain

Wait at least 48 hours after cleaning. Apply on a dry day, 50-90F, with no rain forecast for 48 hours. Apply with a brush for edges and spindles, a roller for deck boards. Back-brush rolled stain immediately to work it into the grain. Two coats on new or weathered wood.

Step 7: Maintain Going Forward

Semi-transparent stains typically last 2-4 years on horizontal surfaces. Recoat when water stops beading. Clean the deck annually with a mild deck cleaner to extend finish life.

Pro Tips

• Temperature matters: stain applied below 50F or above 90F doesn't cure properly.
• Apply two thin coats rather than one heavy coat.
• Semi-transparent stain is the easiest to maintain - it can be cleaned and recoated without stripping.
• Stain deck boards from the house outward so you don't paint yourself into a corner.