Sanding a wood deck before refinishing it is an important process that helps ensure the new finish adheres properly and lasts. Proper sanding creates a smooth, clean surface for the new finish. Here is a step-by-step guide to sanding a wood deck prior to refinishing it.
Introduction
Sanding a deck is labor-intensive but necessary work. It removes any existing finish or stain, smooths the wood, and allows the new finish to properly adhere. Sanding opens up the wood grain so the new stain or sealant can soak in and bond. It also removes any warping or cupping of the boards to create a flat surface. Sanding can be done either by hand or using power tools like an orbital sander. For best results, progress through several stages of sandpaper grits.
Materials Needed
- Sandpaper with varying grits – Start with a coarse 60-80 grit paper to remove existing finishes then move to a finer 100-120 grit. Finish sanding with 150-180 grit.
- Orbital sander or sanding block
- Dust mask
- Eye protection
- Push broom or leaf blower to remove sanding dust
- Drop cloths
- Paint scraper for removing peeling paint or finishes
- Putty knife for fixing indentations, cracks or damaged areas
- Wood filler
- Tack cloth
Safety Tips
- Wear a dust mask to avoid inhaling fine dust particles
- Use eye protection like goggles to keep sawdust out of your eyes
- Work in sections to avoid falls on the sanded surface
- Sweep regularly to remove sawdust and maintain traction
- Work in the direction of the wood grain for best results
Steps for Sanding a Wood Deck Before Refinishing
1. Clear the Deck
Remove all furniture, plants, rugs, and decorative items from the deck. This prevents dust and dirt from collecting on personal items and gives you full access to the entire deck surface.
2. Inspect and Repair Damaged Areas
Look over the entire deck and make repairs before sanding. Fill cracks, dents, or warped areas using wood putty or filler. Replace any loose nails or screws. Sand down high spots or uneven boards. Addressing any damage ensures the deck sands evenly.
3. Remove Existing Finish
Use a paint scraper, putty knife, or sandpaper to remove any existing paint, stain, or sealant. Getting down to the bare wood allows for proper penetration of the new finish. Be sure to wear eye and hand protection when scraping. Sweep away debris before moving on.
4. Start Sanding with Coarse 60-80 Grit Paper
Attach the coarse sandpaper to your orbital sander or sanding block. Keep the sander moving constantly as you work. Apply enough pressure to smoothly remove the previous finish but not so much that you dig into the wood. Always go with the grain. Vacuum up dust as you go.
5. Sand the Entire Deck with 100-120 Grit Paper
Once all existing finishes are removed, switch to a finer 100-120 grit paper. Go over the whole deck including between boards and the outer rim joists. The finer grit levels out the rougher texture from the previous coarser sanding. Vacuum again before the next step.
6. Finish Sanding with 150-180 Grit Paper
For a silky smooth surface, do a final light sanding using an even finer 150-180 grit paper. This removes any remnants of old finishes, opens the wood grain, and further smoothes everything out. Sand with the grain direction. Remove all dust afterwards.
7. Clean Off Dust
Use a brush or leaf blower to remove all remaining sawdust, dirt, and debris. Make sure the deck is perfectly clean before applying any new finish. You can lightly wipe with a damp cloth as a final step if needed.
8. Apply Wood Filler for Indentations (Optional)
For any scratches, cracks, or nail holes that need filler, apply a wood filler now according to the product directions. Once dry, sand the patches flush and smooth. Clean away dust and wipe down the deck. Allow the wood filler to fully cure before applying new stain or sealer.
9. Finish with a Tack Cloth
Wipe down the entire sanded surface with a tack cloth. This picks up any remaining dust and provides a tacky surface for better adhesion of the new finish. Your deck is now ready for staining, sealing, or refinishing!
Tips for Easier Sanding
- Sand in the morning when temperatures are cooler
- Work in manageable sections
- Rent a power floor sander for large decks
- Use sandpaper with a binding to reduce clogging
- Clean the sander pad frequently for optimum sanding
- Wear knee pads to reduce strain from kneeling
Benefits of Sanding a Deck Before Refinishing
- Removes previous finishes so new coatings adhere
- Smooths rough areas and opens wood grain
- Creates a uniform, level surface for refinishing
- Allows stains and sealers to soak in and bond properly
- Provides better traction for walking after refinishing
- Gives the wood a fresh, rejuvenated appearance
- Extends the life of new finishes by prepping the surface
FAQ About Sanding Decks
Should you always sand a deck before refinishing?
Yes, it is highly recommended to thoroughly sand any deck prior to applying new stain or sealant. Sanding removes failing finishes, weathered wood fibers, and surface irregularities so the refinishing products bond and perform properly.
What grit sandpaper is best for sanding wood decks?
Start with a coarse 60-80 grit paper to remove existing finishes, then do an intermediate sanding with 100-120 grit. Finish up with a fine 150-180 grit sandpaper for a smooth surface ready for a fresh finish.
How do you sand between deck boards?
Use a detail or mouse sander to sand between the deck boards. You can also fold sandpaper over a wood block. Sand across the grain first then with the grain direction. Vacuum out the dust between boards.
How do you get old stain off a deck?
An aggressive initial sanding with 60-80 grit paper will remove most old deck stain. For stubborn spots, use a paint scraper or wire brush before sanding. Refrain from using toxic chemical strippers whenever possible.
How long does it take to sand a deck?
It typically takes 2-3 days for a thorough DIY sanding of a standard 500 square foot deck. Hiring pros with commercial sanders can reduce the time significantly. Proper prep work saves time and hassle during staining.
Conclusion
Sanding a deck thoroughly before applying new protective finishes is time-consuming but vitally important for long-lasting results. Always wear proper safety gear and work systematically across the entire deck surface. Progress through varying grits of sandpaper to remove old finishes and smooth the wood. Finish with a tack cloth and the deck will be prepped for optimal adhesion and performance from stains and sealers. Investing the labor upfront leads to a refinished deck that looks amazing and lasts for years of outdoor living enjoyment.