Deck Sanding
An Essential Step

If your porch or deck is looking a little worse for the wear, a good sanding might be in order. Not only is sanding an essential step if you plan to add another coat of paint or stain, but it can help you enjoy your deck much more. Imagine summer mornings spent barefoot, watching the sunrise from your porch. Imagine leaning on smooth, splinter-free railings while your babies enjoy the outdoors safely within the confines of a well-maintained deck.

Depending on the condition of your deck and the results you desire, sanding can be a minimal effort designed to remove the raised grain left after a good power washing, or it can be an extensive restoration effort that brings an aging deck back to life.

Except on newly constructed decks, you should first thoroughly wash the structure with a pressure washer to remove the old finish and any accumulated grime. Most deck stains are easily removed this way. A clean surface makes it easy to identify damaged areas; now is the time to do any repairs.

If you want to stain your deck, and it has been previously sealed with paint, solid color deck stain, or varnish, you'll need to completely remove all traces of the previous finish. A less labor intensive option would be to repaint. Remove any peeling, flaking, or chipping finish with a hand scraper and sand the edges smooth, feathering to blend the painted areas with the unpainted ones.

Types of Sanders

Using a finishing sander on a wood deck floor. There are several types of power sanders; some are better suited to sanding decks that others. Palm and vibratory sanders are the least likely to cause gouging or other damage, and are a good choice for amateurs. Because of their small size, however, the job can take a very long time. Consider using a palm sander for final finishing after using a disc or belt sander.

Disc sanders and large angle grinders are Crowder Painting's choice for most sanding jobs. Coarse buffing pads or sanding discs remove old finish and damaged wood quickly.

Belt sanders are best for the flat tops of railings. They can also be used on the deck floor, but they're hard to control when used this way.

On very large decks, you may be tempted to use the big sanders available at rental outlets. These are primarily used for refinishing hardwood floors, and, while they can work for decks, there are a couple important things to keep in mind.

Because decks are exposed to snow, rain, wind, heat, and cold, they are prone to warping. Twisted or bowed boards are not easy to sand with this type of equipment. New decks which haven't been exposed to much weather, and hardwood decks, which are less likely to warp than their softwood counterparts, are the best candidates for these types of power sanders. Large commercial sanders can be used on the deck floor only; you'll still need a smaller tool for railings, benches, and planters.

Using a floor edger on a T&G porch floor. Floor edgers are lighter and smaller than the other two types of commercial sanders, but they are not usually easy to control on uneven deck surfaces.

Large vibratory sanders are very heavy- often more than 100 pounds. This makes them hard to transport and haul up steps. On the upside, they are easy to use.

Drum sanders are not a good choice for amateurs. They remove a lot of wood very quickly and can cause severe damage to your deck. Avoid this option unless you're an experienced user.

The Right Grit for the Job

Using the appropriate grit is important and depends on the type and condition of the wood you're sanding. Sandpaper that is too rough will remove too much wood and damage the surface of the deck; too fine, and the abrasive won't be able to effectively remove old finishes or smooth damaged areas.

If your deck has a lot of peeling paint, or if the wood is very rough, start with 36 or 60 grit paper. Use a light touch to avoid removing too much wood. The surface will be fairly smooth at this point and can be stained. However, many people prefer a finer finish.

80 or 100 grit sandpaper is the next step. Don't worry about making the deck floor perfectly smooth. You just need to remove any splintering and blend rough or damaged areas into the surrounding surface. Handrails and sitting areas, on the other hand, can benefit from a little more care. Feel free to go even with even finer grits to achieve a perfectly smooth surface that won't snag clothing or hurt your hands.

Once your deck is smooth, you'll need to remove as much dust as possible. Sanding can clog the pores of the wood and make it difficult for stain to penetrate effectively. Using a pressure washer on a low setting will remove sanding dust. Alternatively, use a leaf blower or vacuum cleaner to remove the dust.

Congratulations! Your deck is now ready for a fresh coat of paint or stain.