How to Sand a Wood Deck

When prepping an old wood deck for refinishing, one of the necessary processes is a thorough power washing or scrubbing with a brightener/cleaner. However, this action causes the wood fibers of the decking, steps, and railings to swell and lift away from the wood because they expand with water.

After the wood has been dried, these wood fibers may continue to remain elevated, which can result in splinters. Before applying stain or sealer to your wood deck, you must first perform an essential step that entails lightly but completely sanding the surface. Your refinishing project will yield excellent results as long as you follow this essential step.

Importance of Properly Sanding a Wood Deck

After a deck has been constructed, there is nothing shielding the wood from the elements. If you want to keep it like this, it will eventually become worn out, and the color will start to fade to a color that is somewhere between silver and grey. Applying a protective stain or finish to your wood deck is important if you want it to maintain either its original color or a color of your choosing for as long as possible, despite the fact that a weathered appearance can be aesthetically pleasing. However, before you can apply a stain to your deck, you will first need to prepare it to take the stain. Sanding and meticulous cleaning are required for this step.

Sanding a wood deck creates a surface that is clean, smooth, and free of any splinters or rough areas that may have been there. Sanding the wood before applying a new coat of stain is the best way to ensure that the stain will stick to the wood properly and will continue to look good for many years before it needs to be reapplied.

How Often You Should Sand Your Deck

It's important to know how often you should sand a wood deck in addition to learning how to sand it. Sanding a wooden deck is a necessary step, but you must be careful not to overdo it. Sanding a deck too much could damage the wood. In that case, it runs the risk of becoming fragile and wearing down more quickly. Sanding your deck is a necessary step that must always be taken before applying specific types of stains or finishes to your deck again. To apply a new layer of stain over a water-based stain, the previous stain must be completely sanded away first. Water-based stains typically have a lifespan of between two and three years. The deck does not need to be sanded prior to the reapplication of an oil-based stain, despite the fact that the oil-based stain has a lifespan of about one to two years.

What You'll Need

Equipment / Tools

Putty knife (if needed)
Power washer (if needed)
Scrub brush
Bucket
Screwgun (if needed)
Breathing protection
Eye protection
Knee pads (optional)
Oscillating or random-orbit sander
Detail sander (if needed)
Shop vacuum

Materials

Deck brightener (if needed)
Wood filler (if needed)
Deck screws (if needed)
Sandpaper (60- or 80-grit)
Clean cloths
Tack cloths

Instructions

Wash the Wood

Wash the whole deck as suggested by the producer of the stain or sealant. When power washing, choose a sprayer setting that will not harm the wood. Be sure to properly rinse the deck after scrubbing with a brightener/cleaner to remove any remnants of oxalic acid or other chemicals in the cleaner.

Inspect and Repair the Surfaces

Start by evaluating all surfaces to be sanded, including the surface decking, edges, steps, and railings. Ensure that all fasteners are driven beneath the wood's surface. Some really aged screws may require removal and replacement. Tighten screws that, with time, can rise slightly above the deck, causing the sandpaper to wear out and require replacement. If there are any loose boards, now is the time to secure them with new fasteners.

Before sanding, ensure that any splinters or deep gouges in the wood have been filled or mended. Before proceeding with sanding, ensure that any wood fillers are completely dry and cured.

Sand the Decking Surface

Attach sandpaper of 60 to 80 grit to your electric sander. Avoid sandpapers with finer grits, which will clog the wood's pores and prevent stains and sealants from permeating the wood.

Sand all sections of the surface decking using moderate sandpaper pressure. Check for uniformity of appearance as you progress. Avoid the desire to sand to a mirror-smooth finish; cedar, redwood, and pressure-treated pine are relatively soft woods that can be harmed by excessive sanding pressure.

Use the same method to sand the stair treads' upper surface.

Upon completion, thoroughly vacuum the deck and stair treads using a shop vacuum.

Sand the Board Edges

It may be difficult to sand the outer edges of the deck boards if the railings have a very low bottom baluster rail that makes access impossible. If your ordinary orbital sander won't fit, a smaller detail sander may prove useful here. Again, use 60 to 80 grit sandpaper for the end grain of decking boards, and sand as uniformly as possible, as stains might be absorbed unevenly if the end grains are not smooth. The edges of the boards should be vacuumed and then wiped clean of dust.

Sand the Railings

It is essential to sand the railing of your deck, as it is the most visible piece and the one that attracts the most attention. Additionally, it is essential that the handrail be smooth to prevent hand injuries from splinters.

Utilize 80- to 100-grit sandpaper to meticulously sand all surfaces and crevices on railings. Here, a precise sander or even hand sanding may be required to reach all places; nevertheless, do not sand to the point that the stain cannot penetrate. Vacuum the handrails meticulously.

Vacuum the Entire Deck

Use a shop vacuum to once again vacuum the entire deck, and then use tack cloths to remove any lingering dust from the surfaces. Pay particular attention to cracks and nooks.

Your deck is now prepared to be stained or sealed. Perform these tasks immediately after sanding, before the deck wood can deteriorate or become soiled. If you must delay finishing, clean and wipe the deck with tack cloths again before applying stain or sealant if you must wait.