Deck Refinishing Guide

Cleaning, stripping, sanding, stain vs paint selection, and application techniques

Why Deck Refinishing Matters

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.

Key Principle: The best time to refinish a deck is before it looks bad. Once wood turns gray and starts splintering, damage is already occurring. Preventive maintenance every 1-3 years (depending on product) protects your investment for a fraction of replacement cost.

Stain Types: Transparent, Semi-Transparent, Solid

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.

Oil-Based vs Water-Based Deck Stains

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

Recommendation: For most deck refinishing projects, oil-based semi-transparent stain offers the best combination of appearance, durability, and ease of application. Water-based products have improved significantly but work best when fast dry times and easy cleanup are priorities over maximum longevity.

Deck Cleaning, Stripping, and Brightening

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—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)