Sanding offers option to save aging wood deck

For most people, maintaining a wood deck involves regular cleaning and the periodic application of a deck stain or sealer to protect the wood.

But sometimes that maintenance gets neglected for a variety or reasons, or perhaps you purchase a home with a deck that wasn’t maintained, and now you’re faced with a dilemma. You have a deck with wood that appears structurally solid, but its surface is now too rough and weathered for a simple cleaning and refinishing.

Assuming the substructure of the deck is still solid — all the framing that supports it — one obvious solution is to remove all the deck boards and replace them with new material. But that can easily run into the thousands of dollars, and it’s a shame to waste all that perfectly good lumber.

Luckily, there’s a good alternative for bringing that old deck back from the dead. For most decks where the deck boards are in reasonably good condition, sanding it to remove old finishes and the top layer of weathered wood is an excellent option. It requires some patience, the right equipment, and, of course, some hard work, but it’s not as difficult as it might sound.

Tools and equipment

For this process, you’ll need a machine called a deck sander, which can be rented from most rental yards. This is a large, walk-behind sander that uses a square, orbiting and vibrating pad to do the sanding work. It’s different from the drum-type flooring sander used for sanding hardwood floors, and is actually easier to use.

The sandpaper you’ll be using with this sander is sold in large, precut squares of different grits. You can buy the paper wherever you rent the sander. You’ll need a couple of different grits (see below), and the rental yard can help you with figuring out how much paper you’ll typically need. Take home a few extra sheets; you’ll only be charged for what you actually use.

Besides the deck sander, you’ll need a pad sander or random orbit sander with sandpaper in the same grits as what you’re using for the deck sander. You’ll also need a stiff broom and a shop vacuum or leaf blower. You may possibly also need some epoxy wood filler and exterior deck screws.

The process

Begin by thoroughly sweeping off the deck to remove loose debris, and scrape between the boards to get the debris out of the cracks, as well. Wash the deck with soap and water and a scrub brush to remove loose dirt that will clog the sandpaper, then let it dry.

Next, inspect the deck for loose or raised fasteners. This is a critical step, since raised fasteners will tear up the sandpaper. Resecure all the boards as needed, using exteriorgrade decking screws.

The sanding grit you want to start with will depend on the condition of the deck boards — the rougher and more warped they are, the coarser the grit you’ll want to start with.

Place a square of sandpaper on the deck, then place the sanding pad and sander on top of the paper. Activate the machine, and sand across the deck in large, overlapping sections. You don’t need to bear down on the machine; just guide it and let the sander do the work. After sanding as much of the deck as you can with the deck sander, remove the resulting sawdust.

There will be areas you can’t reach with the deck sander. In these areas, use an electric pad sander or a random orbit sander with the same grit of sandpaper as what you just used with the deck sander.

After the initial sanding, inspect the deck for any holes or cracks. If desired, these can now be filled with an epoxy wood filler. Let the filler dry before moving on to the next sanding step.

Now switch to a finer-grit paper, and repeat the sanding process. Sand a third time with 100 grit.

The final step is to thoroughly sweep, vacuum or blow off the deck to remove all the fine sawdust, then apply a coat of deck finish to protect your beautiful new deck.

Have a home repair or remodeling question for Paul? He can be reached by email at improvingyourhome@ykwc.net.