When it comes to the best way on how to sand a deck, there’s only one real way to do it – like a professional. And that’s exactly what we’re going to be taking a look at today.
From the tools to the methods and all the tips and tricks you need to know, this guide’ll ensure that you achieve perfect results.
How to Sand a Deck in 4 Steps
Before you learn how to sand a deck, you need to get the necessary equipment. Thankfully, you don’t need many things. You just need an electric sander (orbital, sheet or floor drum) – be sure to read my article on the best sanders for decks to find the perfect one – several sheets of sandpaper of various grits (coarse 20-50 grit, medium 120 and fine 250 are great choices), and of course your favorite stain/coat/paint when it’s time to refinish the deck at the end.
To achieve better results, remember to wash the deck first to remove most of the grunge before using the sander.
1 – Wash the Deck
Firstly, use a hard bristle push broom to sweep the deck. In case of any loose fasteners, reset them in their position. Chances are that you may need to reattach some warped boards that have detached from the joists.
Add some detergent to a bucket of warm water and mix. Using a mop, clean the deck and leave the deck to dry for 24 hours. As it dries, use a paint scraper to remove any debris resting in the gaps between boards.
2 – Sand the Wooden Deck
If the boards on your deck are warped and they are made from teak or any other hardwood, first pass coarse 20 to 50 grit sandpaper. For softwood decks, use a 50-grit paper which is less aggressive on the deck.
3 – Sand the Board Edges
Depending on your deck design, it might be tough to sand the outer edges of the deck board, especially if your deck has low bottom baluster rails. To counter this problem, use a smaller detail sander if you find it hard to use a standard orbital/sheet sander.
For the end grain of the decking boards, use sandpaper that has a grit of between 60 to 80. Also, ensure that you sand evenly because the stains are usually absorbed unevenly into the end grain, in case the boards are not uniformly sanded. You also need to wipe the end grains to remove dust just before you move to staining and sealing.
4 – Sanding the Rails
The most visible part of the deck is the rail. It is important to sand it well because most people focus their attention on this part. You also need to smoothen the handrail to avoid splinter formation that can cause injury your hands.
To sand the railings, use sandpaper that has around a 120 grit. To sand all crevices and surfaces perfectly, you can either sand by hand or use a detail sander because you have to get to all these areas to achieve a perfect result. Keep in mind not to make these areas too smooth to a point where stain will be hard to penetrate.
Additional tips on how to sand a deck
- Remember to vacuum and wipe all the surfaces using a clean rag before staining and sealing.
- In case you find cracks, deep scratches or holes, fill them up using epoxy wood filler.
- Use a putty knife to apply the filler and scrape it flat. Let is cure before doing anything else.
- Once you are done with filling, sand the deck again using a fine paper to remove the scratches together with excess wood filler. During the sanding process, you can start with a 20 to 50-grit then slowly climb to 80-grit papers and beyond. Once you are done, blow or vacuum the deck. Lastly, you can make a third pass with a 120 to 240 sandpaper, depending on how fine you want the polish to be.
- Do not sand the railings as much as you sand the deck. The recommended level is to have two passes using an electric sander. For the first pass, you can start with an 80-grit paper, and on the second pass, use a 120-grit paper.
- Pick a finish of your choice to seal the deck once you are done with the final sanding.
Always check the weather before you start working on the deck. Plan ahead to only work on the deck when dry weather is going to be the norm for a lengthy period of time. Avoid sanding if rains seem to be on the horizon because water will raise the wood grain. When this happens, you will have to sand the deck down once again after the weather dries out.
Now that you know how to sand a deck like a true pro, it’s time to roll up those sleeves and get to work – it’s worth it in the end, believe me!