Which Grit Sandpaper for Deck Sanding?

Last Updated on March 26, 2022 by Jason K. Long

Sanding deck surfaces with 100-grit sandpaper.

One crucial step in staining your deck is the sanding process. Sanding your deck before applying a stain is an excellent way to enhance the smoothness of the finish. Besides, you will indeed get the preparation right if you use the right tools and the appropriate sanding grit when sanding the deck. With the correct sandpaper grit, you can simplify the sanding process and make your new deck or old deck appear good for several years to come.

You can use 80-grit sandpaper and a palm sander for sanding hard-to-reach areas that larger machines can’t easily access. You can also use 100-grit sandpaper for the railing, especially if you need to remove an old heavy coat. You can also do two passes of sandpaper, one with the 80-grit and the other with 100-grit sandpaper. Afterward, you can vacuum the deck or use a leaf blower to do away with the dust. Then, sand again using 100-grit sandpaper and clean off the dust again. You can apply the finish afterward.

Sanding for Quality Finish

The sanding process of the deck is a crucial step in finishing or staining the deck. Hence, you can’t sidestep or skirt around this process. Moreover, when sanding, you need to do it with ease and correctness. So, before asking how to best stain your deck, you should first ask how to best sand your deck. 

ALSO READ:  How to Restain Cedar Siding

Once the deck panels get positioned and installed, they stand unprotected from the harsh environment of the outdoors. Their color will deteriorate if you let them stay there unprotected. 

Nevertheless, it will help dry the deck before you stain it entirely. It will help if you prepare the coating before adding the stain. Besides, the deck needs sanding to remove old paint and smoothen the surface. Moreover, you can remove rough edges and splinters as you sand. 

Sandpapers come in different grit or coarse. So, you need to select the best grit of sandpaper. The thing is, you should not sand the deck to glass-smooth perfection. You will give the wood a hard time absorbing the stain if you do so. If you use high-grit sandpaper, you risk making the pores impervious to stain.

Moreover, some wood types like redwood and cedar get damaged by hard sanding. So, it will help if you sand correctly to avoid damaging the deck panels. 

Guides on Choosing the Right Sandpaper Grit

As mentioned above, the quality of your deck finish will depend on the way you sand and finish the deck. It also depends on the type of wood you use for your deck panels. If you are using a hardwood like redwood, you need to smoothen the surface of the hardwood panels to ensure a quality finish. You can use up to 20-grit sandpaper for the first sanding. Afterward, you can use progressively finer ones for the best surface preparation for the redwood deck. 

If you’re using softwood for your deck, you can damage the wood surface, primarily if you use power tools. Therefore, it will be best to use 50-grit sandpaper for first-time sanding the softwood deck. If you don’t want to sand manually, you can use orbital or oscillating sanders for softwood. 

ALSO READ:  Best Belt Sanders for Deck

If you would sand pressure-treated lumber, however, you should take extra care not to inhale the dust. Pressure-treated timber are treated timber, and thus, it contains preservative additives or chemicals that can be harmful to your health. You should also use 60-150 grit sanding paper for your pressure-treated deck panels.

Why Should You Not Aim for a Glass-smooth Surface?

You can use 60 to 80-grit sandpaper using your power sander. The thing is, you don’t want to create the smoothest possible surface when sanding decks. The reason for this is that you might make it difficult for the wood to absorb the stain if you smoothen it too much. Thus, you must avoid the finer-grit sandpapers. Remember that if you go for the smoothest finish, the wood’s pores get clogged, preventing the stain from being absorbed by the wood. 

It will be best to go for medium-grit sandpaper when sanding deck panels. You should also use medium pressure on your power sander. You can use 60 to 80-grit sandpaper when sanding the deck panels. But when sanding the railings, you can use 80 to 100-grit sandpaper. You can sand the railings manually because it is hard to sand using the larger sanding machine. As a caveat, you should also avoid sanding the railings to glasslike smoothness, for the stain will also find it hard to penetrate the railing wood. 

Remember that the grit size refers to the number of coarse particles in the sandpaper. When the number is less, it means it is scratchy. If it is high, then it is more abrasive. With finer grit, you will notice a sizeable number of scratches, leading to a smoother finish.  

ALSO READ:  How To Apply Teak Oil


Sanding is a crucial step in preparing the deck for staining or painting. As such, you should not sidestep this process, for it is necessary. Before sanding, you should check the deck for protruding screws or nails and countersink them before beginning to sand. These protruding nails might rip the sandpaper once it passes over those nails, thus delaying your work. 

It will be best to use a belt sander when sanding large deck surfaces to speed up the sanding process. Moreover, if you need to remove old stains, you should use coarse-grade sandpaper, then go for the finer grade for a smoother finish. You can also use a finishing sander for sanding the corners and edges. Besides, you should not forget to sweep the surface with a broom or vacuum the deck surface before applying a stain.

Related Posts:

Leave a Comment