How to Refinish a Deck
Clean, brighten, sand and stain, sized to your deck.
Doing this on a real job? Refinish a deck: materials, tools and steps sized to your numbers.
Get the planWhat does your deck need?
Clean, brighten and restain
Stain: Semi-transparent
- Clean and scrub
- Brighten
- Sand 60 to 80 grit if fuzzy
- Stain
Deck stain calculator
- Semi-transparent stain
- 5 gal
- 452 sq ft of surface incl. rails and stairs
- Prep
- 1 cleaner, 1 brightener, 2 sanding packs
- Cost
- $460 DIY
- Pro: $900 to $2,100
Save this as your deck refinish plan: the shopping list on your phone, a checklist to tick off over the 3-day job, a nudge when the forecast shows 48 dry hours between 50 and 90 F, and a restain reminder in 2 to 3 years.
Refinish a 300 sq ft deck
Clean, sand and stain 300 sq ft of decking plus 40 ft of railing. Two coats of semi-transparent deck stain take about 5 gallons.
- Materials
- $460
- Time
- 1 weekend
- Level
- Easy
- 1
Check the weather and the wood
You need 2-3 dry days between 50 and 90 F with no direct midday sun on the boards. Splash water on the deck; if it beads, the old finish has to come off.
- Forecast: 48 dry hours after staining
- Water bead test
- Note rotten or split boards
- 2
Repair and prep
Replace rotten boards, set popped nails, and cover siding, plants and the house wall with plastic.
- Replace damaged boards
- Sink nails or swap for screws
- Cover plants and siding
- 3
Clean
Spray cleaner on all 452 sq ft of wood, let it dwell 10-15 minutes without drying, scrub, then rinse with the pressure washer held 12" away and moving with the grain.
- Wet, apply, dwell
- Scrub with the grain
- Rinse low pressure, wide tip
- Deck area
- 300 sq ft
- Railing
- 40 ft
- Stain
- 5 gal
- Est. cost
- $460
8 steps · 8 tools · 6 materials
5 more steps, the full tool list and a shopping list you can check off as you go.
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3/5Refinish a 300 sq ft deck
Finished in 1 weekend · $460 DIY
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Weekend timeline
- Day 1Repair boards, set nails, mask plants and siding, clean and brighten
- Day 2Let it dry: 24 to 48 hours, wood under 15% moisture
- Day 3Sand 60 to 80 grit, blow off dust, stain rails top-down, then boards 2 to 3 at a time
- Day 4 to 6Light foot traffic after 24 to 48 hours, furniture after 72 hours, rugs after a week
Stain between 50 and 90 F (60 to 80 F is ideal), under 70% humidity, out of direct midday sun, with no rain for 24 to 48 hours after. New pressure-treated wood: wait until it soaks up water, usually 1 to 6 months.
Deck refinishing involves cleaning, repairing, and applying protective coatings to wood decks to prevent moisture damage, UV degradation, mold growth, and wood rot. Unprotected wood can deteriorate in 3-5 years, while properly maintained decks last 15-30+ years.
Wood decks face constant assault from sun (UV breaks down lignin), moisture (causes swelling, warping, and rot), mold/mildew (feeds on wood fibers), and foot traffic (wear). Regular cleaning and recoating creates a protective barrier that dramatically extends deck life.
| Stain Type | Coverage | Longevity | Appearance | Best Use |
|---|---|---|---|---|
| Clear Sealer / Water Repellent | No pigment, wood grain fully visible | 6-12 months (shortest) | Natural wood color, slight sheen | New wood that you want to keep natural. Requires frequent reapplication. Minimal UV protection. |
| Transparent / Toner Stain | Light pigment, wood grain clearly visible | 1-2 years | Enhances natural wood color, shows texture and grain | Premium wood species (cedar, redwood) where you want natural look with moderate UV protection. Not for weathered wood. |
| Semi-Transparent Stain | Moderate pigment, grain visible, some color tinting | 2-3 years | Shows wood grain but adds color. Most popular choice. | Best balance of protection and aesthetics. Works on new and weathered wood. Good UV protection. Easy to recoat. |
| Semi-Solid Stain | Heavy pigment, grain texture visible, color opaque | 3-4 years | Hides wood variations, shows texture but not grain | Weathered decks with discoloration. Hides imperfections. Good UV protection. Medium maintenance. |
| Solid Stain / Deck Paint | Full opacity, like paint, no grain visible | 4-7 years (longest) | Completely covers wood. Painted look. Uniform color. | Very weathered decks, pressure-treated pine, or when paint-like finish desired. Maximum UV protection but hardest to maintain, peeling requires scraping. |
Choosing the Right Opacity
- New deck, premium wood: Transparent or semi-transparent to show off grain
- Aged deck, moderate graying: Semi-transparent (most versatile)
- Weathered deck, uneven color: Semi-solid to hide discoloration
- Very old or painted deck: Solid stain or paint (only option once painted)
- Pressure-treated pine: Semi-solid or solid (less attractive grain to show)
- Rule: You can go darker/more opaque later, but not lighter. Start less opaque if uncertain.
| Characteristic | Oil-Based Stain | Water-Based Stain |
|---|---|---|
| Penetration | Deep penetration into wood fibers | Surface film with some penetration |
| Appearance | Rich, natural, enhances grain depth | Can look milky/plastic if over-applied |
| Durability | Excellent, lasts 2-4 years typically | Good, lasts 2-3 years, improving with newer formulas |
| Application | Easier, self-levels, hides brush strokes | More technique needed, can show lap marks |
| Dry Time | 24-48 hours between coats, 48-72 before traffic | 4-6 hours between coats, 24 hours before traffic |
| Cleanup | Mineral spirits or paint thinner required | Soap and water (much easier) |
| VOCs / Odor | High VOCs, strong odor during application and cure | Low/no VOCs, minimal odor, eco-friendlier |
| Mildew Resistance | Natural mildew resistance (less food for mold) | Requires mildewcide additives |
| Maintenance | Fades evenly, easy to recoat (clean and apply) | Can peel/flake if over-applied. May require stripping. |
| UV Protection | Excellent with proper pigment level | Good to excellent (depends on formula) |
| Temperature Sensitivity | More forgiving, can apply in cooler temps (45°F+) | Temperature-sensitive, needs 50-90°F typically |
| Cost | $$-$$$ (premium products) | $-$$ (generally less expensive) |
| Best For | Horizontal surfaces (decks, railings), traditional look, areas where durability is priority | Quick-drying needs, eco-conscious users, easier cleanup, cooler climates where freeze-thaw common |
Deck Cleaning Process (Weathered/Dirty Decks)
Step 1: Sweep and Prep
- • Remove all furniture, planters, and debris
- • Sweep thoroughly, remove all loose dirt and leaves
- • Hammer down protruding nails, tighten loose screws
- • Cover plants with plastic, cleaners can harm vegetation
Step 2: Apply Deck Cleaner
- • Choose cleaner: Oxygen bleach (sodium percarbonate) for mold/mildew, safe for plants. Sodium hydroxide-based for heavy graying/tannin removal, harsher. Chlorine bleach kills mold but lightens wood and harms plants, last resort.
- • Mix per product instructions (typically 1:4 to 1:1 concentrate:water)
- • Pre-wet deck with garden hose
- • Apply cleaner generously with pump sprayer or brush
- • Work in sections to keep deck wet
Step 3: Scrub and Dwell
- • Scrub with stiff deck brush (not wire brush, damages wood fibers)
- • Let cleaner dwell 10-15 minutes (don't let dry, rewet if needed)
- • For heavy mold, agitate again with brush after dwell time
Step 4: Pressure Wash or Rinse
- • Pressure washer: 500-1,200 PSI max. Use 25° or 40° nozzle. Follow grain. Stay 8-12" away. Test first!
- • Garden hose: Acceptable for lightly soiled decks. Takes longer but zero risk of damage.
- • Rinse thoroughly, cleaner residue prevents stain adhesion
- • Rinse plants after to remove any cleaner overspray
Step 5: Allow to Dry
- • Let deck dry 48 hours minimum (72 hours ideal)
- • Check moisture with meter if available (19% or less for staining)
- • Dry, sunny weather critical, no rain in forecast
Deck Brightening (Critical Step Often Skipped)
- • Why brighten: Deck cleaners are alkaline, raise pH and leave wood fuzzy. Brighteners (oxalic acid or citric acid) neutralize alkalinity, restore natural color, and smooth wood fibers.
- • When to apply: After cleaning and rinsing, while deck is still damp or after it dries
- • Application: Mix per instructions, apply with pump sprayer or brush, scrub lightly, let dwell 10-15 minutes, rinse thoroughly
- • Result: Wood returns to natural honey/tan color (removes gray). Smoother surface. Better stain adhesion.
- • Is it required? Not mandatory but highly recommended, dramatically improves final appearance and stain penetration
- • Cost: $15-30 for typical deck. Worth the investment for professional-looking results.
Stripping Old Stain or Paint
- • When needed: If previous coating is peeling, flaking, or you're changing stain color significantly. Solid stains/paints usually require stripping.
- • Chemical stripper: Apply gel or liquid stripper per instructions, let dwell 15-30 minutes, scrub with stiff brush, pressure wash or scrape off loosened material
- • Sanding: 40-80 grit with orbital sander or belt sander. Effective but time-consuming and creates dust. Required for smooth solid-stain finish.
- • Combination approach: Strip heavy buildup with chemicals, sand any remaining spots and for final smooth surface
- • Semi-transparent stains: Often don't require stripping: you can clean and recoat with same opacity or darker
Deck Cleaning Products Comparison
- Oxygen bleach (sodium percarbonate): Safest. Effective on mold/mildew. Plant-friendly. Requires warm water to activate. (~$20-30)
- Sodium hydroxide cleaner: Strong. Removes gray/tannins effectively. Can darken or lighten wood depending on formula. Protect plants. (~$25-40)
- Chlorine bleach: Kills mold fast. Lightens wood significantly. Harms plants and corrodes metal. Not recommended unless necessary. (~$5)
- Commercial deck cleaner kits: Pre-measured cleaner + brightener. Convenient. More expensive. Reliable results. (~$40-60)
Sanding
- When: wood fuzzed by washing, splinters, solid stain or paint, mill glaze on new boards, or uneven color.
- Grit: 40 to 50 for heavy removal, 60 to 80 for general prep. Do not go finer than 80 before a penetrating stain or it will not soak in; 100 to 120 only under solid stain.
- Tools: a rented drum or orbital floor sander for boards, a random orbit or hand sanding for rails. Always with the grain, then blow or sweep off all dust.
How to apply deck stain
- Brush (3 to 4 in): best penetration; use it on rails, balusters and board ends.
- Pad or roller (3/8 to 1/2 in nap): fast on boards; back-brush any puddles.
- Pump or airless sprayer: fastest; always back-brush and mask everything.
- Order: rails top-down first, then boards 2 to 3 at a time along their full length, working away from the exit so you do not stain yourself in.
- Second coat: wet-on-wet within the label window for penetrating stains; semi-transparent stains often need only one coat on old wood.
Which stain for your deck
| Wood | Look you want | Stain | Base | Lasts |
|---|---|---|---|---|
| New or 1 to 5 years | Wood grain, natural color | Transparent or semi-transparent | Oil or water | 1 to 3 yr |
| Weathered, gray, sound | Even color, some grain | Semi-transparent or semi-solid | Oil | 2 to 4 yr |
| Old, patched, mixed boards | Uniform color | Solid stain | Water (acrylic) | 4 to 7 yr |
| Cracked, checked, splintery | New surface | Deck resurfacer | Water | 5 to 10 yr |
| Ipe or other hardwood | Rich natural tone | Hardwood penetrating oil | Oil | 1 yr |
Deck refinishing mistakes
- Lap marks: stopping mid-board. Keep a wet edge and finish each board end to end.
- Staining in direct sun: it flashes dry before it soaks in. Work in shade, morning or evening.
- Sanding finer than 80 grit: closes the grain so penetrating stain sits on top and peels.
- Skipping the brightener: leaves the wood alkaline and blotchy after cleaning.
- Too thick a semi-transparent coat: it stays tacky and peels. Wipe or back-brush the excess.
- Staining new pressure-treated wood too soon: wait until water soaks in, usually 1 to 6 months.
Frequently asked questions
How often should you refinish a deck?
Stain, paint or sealer: which is best for a deck?
Can you stain over old deck stain?
How long after rain or washing before staining a deck?
Should you pressure wash a deck before staining?
How much stain do I need per square foot?
How much does it cost to refinish a deck?
Can you refinish a composite deck?
Prep with the pressure washing cheat sheet and the power tool safety guide, price new boards in the deck calculator, and figure solid stain like paint with the paint calculator.
Building or rebuilding? Span tables and code rules are in the deck building cheat sheet.
Questions about this sheet
Ask about your situation. Posting needs a free account, and your question carries over so you get an answer with your project in view. Questions we hear often get answered on this sheet.
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