How to Waterproof Wood

| Last modified on January 27th, 2022

At some point, you’ll want to make sure that the wood around your home is safe from damages that could be taken on from water. Water is the biggest contributor to wood rot and a vector for mold and bacterial growth. In order to avoid this, waterproofing is necessary. Yet even if your wood has been treated in the past, it might be a good idea to consider a re-coat, particularly if it hasn’t been covered in several years. The guide below will help you know which items you need to get started, along with point-by-point sealing instructions from the job’s start to finish. Let’s begin!

What You’ll Need to Get Started

Here are some of the things that you’ll need to get started with waterproofing your wood. You won’t even every single thing that’s listed but make sure that you at least have the stain, sealer, and brush to begin doing the work.

  • Wood Cleaner – There is an endless number of ways for you to clean wood. You could use vinegar, soap and water or a combination of both. If you’re going to seal off a deck, a pressure wash might be a good idea as well. Just be sure that you give the wood some time to dry out before you begin to seal.
  • Paint Stripper – Paint Stripper come in lots of varieties. You could do this with a scraper, or even a buffer that has a scraping pad attached. There are also paint removing solutions sold online; finding the right way to get old paint or sealer off of your wood is easy. However, be sure that you don’t scratch up the wood too much in the process.

The best paint strippers for wood are often automated, so focus your search on these tools first.

Best Choice
PORTER-CABLE Heat Gun, 1500-Watt (PC1500HG)
PORTER-CABLE Heat Gun, 1500-Watt (PC1500HG)
Best Paint Stripper for Wood Overall (Editor's Choice)

  • Very durable on the outside; built to last a long time.
  • Doesn't leave the palms sweaty when held for long periods; easy to hold.
  • It can support its own weight and be sat upright.
  • Heats up in only a few seconds.

Read Verified Customer Reviews
  • Paintbrush – No wood sealing job can begin without a paintbrush, You may even have one laying around somewhere in your garage already. But if not, be sure that you acquire one before beginning. Even with a paint roller or sprayer at hand, a brush will ensure that you’re able to get into those tight corners that other painting tools have trouble with reaching.
  • Paint Roller – A paint roller can cover a very large area in a short amount of time. They’re useful for sealing floors, ducks, outdoor panels and wooden shingles. But as mentioned already, you’ll want to have a backup brush around in case you find yourself in a hard-to-reach spot. But don’t worry about getting this if the wood your treating is very small.
  • Safety Goggles – Safety always comes first. To keep anything from flying into your eyes, try and find a good pair of safety goggles. This is especially important for people that are going to seal off the wood with a sprayer. Wind gusts can happen at any time, with the last thing that you want occurring is for the solution to end up in your face whenever the wind picks up.
  • Hand Protection – Rubber gloves are best, but anything could work. You don’t have to do it, but remember that strainers can sometimes carry a strong odor and consist of bonding agents that are hard to wipe off. Having on a pair of gloves would prevent anything from getting on your skin.
  • Wood Sealer – The best wood sealers are usually sold in cans that resemble ordinary paint. Finding them is easy to do. Yet since you’re trying to waterproof, be sure that the sealer contains the ingredient polyurethane. When you apply it, the polyurethane will seal off the top layer of the wood and prevent stains and moisture from getting inside. If you want, you can apply more than one coat when the first one dries. Some brands recommended this more than others so be sure that you read the instructions of the product you end up with.
Best Choice
Ready Seal 512 5-Gallon Pail Natural Cedar Exterior Wood Stain and Sealer
Ready Seal 512 5-Gallon Pail Natural Cedar Exterior Wood Stain and Sealer
Best Wood Sealer Overall (Editor's Choice)

  • Ready to use immediately; no primer is needed.
  • The sealer can be applied in a variety of ways, including spray, brush, and roller.
  • It doesn't leave streaks after the sealer is fully dried.
  • Forms a waterproof seal in two hours.

Read Verified Customer Reviews
  • Wood Stain – Wood stains are a little different than a sealer. Their primary purpose is to protect the wood from UV damage from the sun. As such, they’re oftentimes best when working with wooden fixtures that are outdoors. Some of them aren’t great at waterproofing but brands to exist that contain polyurethane. Remember to read the ingredients of the packaging before you buy. In any case, it’s still a good thing to have around if you want to cover the sealer with an extra coat.
  • Wood Filler – Although this is the last item, wood filler would be something that you would apply before beginning to seal. As you clean the wood, take note of any holes or other damages portions of the wood. It would be a good idea to seal up these portions, as such areas are typical to spots where water could penetrate through after sealing is done. It might not happen quickly but over time, holes and cracks also make excellent entry points for mold growth. The best wood fillers will allow you to sand and paint over it as if it were never there.
Best Choice
Bondo 20082, Quart Home Solutions Wood Filler
Bondo 20082, Quart Home Solutions Wood Filler
Best Wood Filler Overall (Editor's Choice)

  • It has a quick setting and drying time.
  • It doesn't crumble or chip away when in contact with heat, rain, and water.
  • Looks good when painted over.

Read Verified Customer Reviews

Detailed Instructions

Step 1: Ventilate Your Working Location

how to waterproof wood - step1

This is more important when you’re working in an indoor location. Proper ventilation is important since it’ll allow the sealer to dry quickly once the work is completed.

Step 2: Clean the Area

how to waterproof wood - step1

Use a cleaning solution to get up any dirt and grime from the wood before you begin sealing it. And remember to let it dry, particularly if you use water or pressure wash.

Step 3: Use a Filler/Putty

how to waterproof wood - step3

Fill in any problem areas that you come across during the cleaning. Keep in mind that filler may take several hours before becoming completely dry. Sand down the area once the filler has completely hardened.

Best Choice
Bondo 20082, Quart Home Solutions Wood Filler
Bondo 20082, Quart Home Solutions Wood Filler
Best Wood Filler Overall (Editor's Choice)

  • It has a quick setting and drying time.
  • It doesn't crumble or chip away when in contact with heat, rain, and water.
  • Looks good when painted over.

Read Verified Customer Reviews

Step 4: Begin Sealing

how to waterproof wood - step4

Begin to seal the wood, using either a paint roller for large sections and a smaller paintbrush to cover corners and hard-to-reach areas. If you’re using the brush online, you may want to ensure that no streaks are leftover. Fortunately, most sealers and fillers sold on the market today have ingredients inside that’ll prevent streaks from developing.

Best Choice
Ready Seal 512 5-Gallon Pail Natural Cedar Exterior Wood Stain and Sealer
Ready Seal 512 5-Gallon Pail Natural Cedar Exterior Wood Stain and Sealer
Best Wood Sealer Overall (Editor's Choice)

  • Ready to use immediately; no primer is needed.
  • The sealer can be applied in a variety of ways, including spray, brush, and roller.
  • It doesn't leave streaks after the sealer is fully dried.
  • Forms a waterproof seal in two hours.

Read Verified Customer Reviews

Step 5: Allow it to Dry

how to waterproof wood - step5

Drying is usually contingent on the amount of square-footage you cover. If you’re sealing a deck or wooden floor, expect the drying to take anywhere from 12 to 24 hours. You may have to wait even longer, especially if you like in a humid region. Because of this, try to pick a time of the day that has the lowest amount of humidity to seal, such as midday.

Step 6: Keeping it Clean

how to waterproof wood - step6

After the work is done, you’ll quickly discover that the hardest part is keeping the wood in good shape afterward. Remember to clean it regularly, more so when during periods of the year when the pollen count is high.

Additional Guidelines

How to Waterproof Wood Furniture for Outdoors

Wooden furniture generally requires the same steps as shown above, but on a somewhat smaller scale. You might also have to do more sealing. Inspect the wood to ensure that you don’t miss ay crevices; these would require filling with putty or filler. However, as this would be placed outdoors, Try and find one that isn’t water-based. After that’s done, sand and begin your seal as instructed on the brand’s label.

How To Waterproof Painted Wood

Painted wood can be treated with a polyurethane sealant as well, although you may want to consider getting a stain to go over everything when the first coat dries. The stain will protect the paint from UV damages. If you can, try to find one that’s colorless, unless you’re okay with your paint looking a bit darker than normal.

How To Waterproof a Deck

Decks often require a lot of sealers. You’re going to need good cleaning supplies, more so if you haven’t wiped the deck down in a long time. Use strainers or sealer with waterproofing ingredients. If you live in an area with a lot of rain, be sure that you pick a good day from the week to do this, in order to give the solution time to harden.

How To Waterproof Wood for Bathroom

Look for sealers that leave no strong odors to seal off your bathroom, as they’re usually the most closed-off rooms in the average person’s home. For cabinets and countertops, a small brush should be enough to finish your work off quickly.

How To Make Wood Countertops Waterproof

A polyurethane sealer that’s colorless and hardens quickly would be the best for your countertops. Just find a brand that doesn’t instruct for you to use more than one coat.

How To Waterproof Wood for A Boat

Check to see how many layers of wood there are on your boat. The more layers typically require a greater number of coats, which means that sealing could take a day or two to complete.

How To Waterproof Wood Fence

Wood fencing is best sealed with a stain/stealer combination. Since wooden fences receive a large amount of sunlight, they’re usually the first pieces of wood to begin fading on one’s property, which is bound to happen if the wood isn’t protected.

Summary/Conclusion

When you’re done waterproofing the wood around your home, be sure to inspect for any areas that you may have missed. Fill in any holes or other openings with a putty, filler, and/or sawdust mixture. Although the wood might be protected from water for a while, It’s up to you to maintain proper upkeep. But as long as you’ve sealed off everything with the tips shown above, this final step should be the least of your worries.

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