Now that we’ve already taken a close look at the journey your lumber will take from the forest to the work site (see Parts 1 & 2), we’ll explore the different ways you can get rid of the grime and bring out the natural beauty in your decking boards. If you follow these steps carefully, you’ll likely achieve the type of impressive, long-lasting results you’re aiming for in this finishing process. The first step you’ll want to take care of is sanding away the rough areas on your decking boards.

Sand Away the Rough Patches

When a planer is run on a decking board and it ends up going against the grain, it will naturally cause a tear in the wood. As much as woodworkers try to go along with the grain of the wood, it’s not always predictable. There are times when the wood grain will change direction unexpectedly. This is especially true when a board has several swirls or knots in the grain. When you see those patterns in the decking board, you’ll very often have plenty of rough spots come up on the surface of the wood where the planer went against the natural grain direction. Or perhaps you’ll have a board that doesn’t show visible knots but was cut from a part of the log where knots were in close proximity. Rough spots can arise in this situation too.

If you’re working with quartersawn or verticle grain boards, you can also expect to find rough patches. That’s because of the impact the growth rings will have on the direction of the wood grain. In these types of boards the grain is even harder to predict, which can lead to the presence of even more rough areas. In hard tropical species such as Cumaru and Ipe, raised patches are extremely common; these patches have a tendency to raise up noticeably higher than the rest of the board surface. That’s one reason it’s not a great idea to walk on new decking boards, or any decking boards, with bare feet.

Why, you may ask, don’t the workers at the lumber yard just take care of the problem by sanding down the rough patches in advance with a drum sander? The answer is that the entire board would be evenly sanded down if you used a drum sander. This would end up wasting some perfectly good, solid wood from the areas of the board that wasn’t rough. Since the percentage of raised grain area usually tends to be 10% or less of your entire board surface, that’s a lot of extra trouble to take and a lot of good wood to waste.

Instead, you can take a more efficient approach. Simply wait until the deck is already installed and then go over the rough patches with a random orbital sander or hand belt sander. This method will target only the problem areas of the boards while leaving the rest of the decking intact.

In our next article, we’ll look at some more ways you can give your newly installed deck a finished appearance.