restaining a new deck sanding first

Do I Need to Remove Old Stain Before Restaining a Wood Deck?

In Exterior Wood, Tips by Jamie

Staining your deck is important because it protects it from the elements and keeps it looking great. But many people are unsure whether they need to remove the old stain before applying new stain.

If you are using the same color, or something very similar, you don’t need to remove the old stain. However, if you are changing to a different color or the stain is in particularly bad condition, you should remove it.

This article will give you some tips on staining over the existing stain, and let you know when you should remove the old stain before finishing your deck again.

What Happens if You Stain Over Stain?

Staining over existing stain is perfectly fine, in a lot of cases. As long as the colors are the same and the deck is ready to accept more stain, it will look fine. You will only run into problems when you are changing color or using a stain with a different formulation.

You can check whether the deck is ready to accept more stain by putting a small amount of water onto it. If the water soaks in, you are good to go. But if it beads on the top, that means that the wood fibers are saturated and unable to take more stain. In this case, you need to remove the old stain before restaining.

How to Restain a Deck Without Stripping (Step by Step)

1. Remove loose debris

Start by sweeping the deck with a broom to remove all loose debris, such as leaves and dirt that are sitting on the surface of the wood.

2. Clean the deck

Although you do not need to remove the stain, you do need to clean the deck first. An all-purpose deck cleaner with basic detergents will work for general dirt and grime. Alternatively, you can make a homemade deck cleaner using a vinegar and water solution, or even simple washing up detergent.

However, if your deck has mold and mildew, you need a specific deck cleaner that contains mildewcide. Apply your cleaner based on the manufacturer’s guidelines, making sure to get in with a brush and thoroughly scrub the deck. At this point, some of the old stain may come away, but don’t worry about trying to get it all off.

You can also use a power washer to clean your deck and remove mildew. Once finished, rinse the deck properly with a hose and leave it to dry. You may get the fuzzies, read our guide here to learn what to do if you get them after power washing. 

3. Consider using a deck brightener

If your deck is relatively old, it may have been weathered over the years and developed a grey coating over the surface. You can remove this weathering with a deck brightening solution. Consider doing this before applying your stain if you want to bring your deck back to life.

Once you have finished cleaning, brightening, and rinsing your deck, give it 24-48 hours to fully dry before applying more stain.

4. Apply your new stain

staining a wood deck

When you are sure that the deck is completely dry, you can apply your new stain. Again, follow the guidelines on the can and make sure you get even coverage. Use a good quality brush with natural bristles and apply stain in long strokes down the full length of the boards. This will help avoid drips.

Staining along the full length of the board from one end is also important because it avoids overlap. If you come in from both ends and meet in the middle, you end up with a crossover area where there is more stain, and that causes a blotchy finish.

Make sure to work the stain into any gaps and joints between the boards, and don’t forget the ends of the boards. if there is any excess stain that hasn’t soaked in, wipe it off carefully.

Give yourself time to apply 2 coats before it rains and the deck gets wet.

When Should You Remove the Old Stain Before Restaining?

If you are changing the color of the stain, it’s a good idea to remove the old stain. This is especially true if you are going for a lighter color because the old dark stain will hide the new stain. Consider the formulation of the stain if you are changing to a different brand too. Mixing different ingredients could potentially cause issues with the finish so it’s better to be on the safe side and strip the deck first.

You also need a good surface to apply stain. If the old stain is in very bad condition and your deck is covered in a thick layer of mildew, it’s best to strip it right back and start from scratch for the best results.

Can You Add Water-Based Stain Over Oil-Based Deck Stain?

Yes, you can use water-based stain over oil-based stain, you just need to be careful. The water-based stain will only bond properly if the existing stain is completely dry. Make sure that the colors are similar and check the ingredients for anything that may react with one another.

When Should I Power Wash My Deck Before Restaining?

Power washing is great for removing thick dirt and heavy layers of mildew. As long as you keep the pressure relatively low (between 1000 and 1200 psi) you can thoroughly clean it without damaging the wood underneath. This may not be necessary when the deck is in good condition and a simple mop and bucket will suffice.

You can also use a power washer to help you strip the deck completely. Some power washers have a chemical intake, so you can mix a deck stripper with the water and use that to blast away the old stain.

When Should I Sand My Deck Before Restaining?

You should sand your deck before using a heavy-duty cleaner if the wood is severely weathered, or if you want to change the color of the stain. Sanding is also useful for damaged decking. If you have big scratches and dents in the decking, you can sand them out before you clean and stain it again.

Sanding shouldn’t be necessary on newer decking that is in fairly good condition, but it may be recommended on older wood if you want to make it look fresher.

When Is Deck Stripper Recommended?

Deck stripper is used when you want to completely remove any old stain. It will break down the stain, making it a lot easier to wash it away with a hose or pressure washer. In some cases, you could just sand the stain but if you are having difficulty removing it, deck stripper makes life much easier.

You can also buy deck stripper products that will clean mold and mildew at the same time. So, if you have decking that is in poor condition and you want to start from scratch, deck stripper is the way to go. But you should use a simple deck cleaner if you just need to prepare the surface for fresh stain.

#1 Deck Wood Stain Stripper - 1 Gallon - Ready to Use, Wood Stain Remover Strips Weathered, Water-Based and Oil-Based Finishes

Check out the deck stripper by SaverSystems, it does the job well and I recommend it. 

Final Thoughts

Deciding whether to remove old stain or not can be difficult. Ideally, you should stain over it because it saves time and money. However, you have to consider what the finish will look like. If your deck is in good condition and you are just hoping to refresh it with the same stain, just use a good-quality deck cleaner first. But if the stain has seen better days and there is serious weathering on the wood, it’s worth taking the time to strip it back completely and start from scratch.

About the Author

Jamie

Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.