How to waterproof wood and brick for outdoor use

Here we cover everything you need to know when it comes to brick waterproofing and sealing off all the surfaces in your garden from water damage.

19 July 2019

plank of wood being painted with medium brush
Out of home

Key steps

  1. Clean and dry outdoor surfaces thoroughly first
  2. Apply a waterproofing product in thin even layers
  3. Wait for it to dry
  4. Apply more coats as necessary

Any garden furniture or structures on the outside of a home need to be weatherproof, but knowing how to make wood waterproof or protect brickwork from the elements isn't always easy. Here we outline the correct step-by-step method for waterproofing a range of common garden materials.

Waterproofing brickwork and wood in your garden can be a big project, so be sure to set aside enough time to get it done properly. 

How to waterproof plywood

You might be using plywood in your garden for raised flowerbeds or other landscape gardening features. It’s a really handy material and you can help it last for longer by effectively treating the wood for outdoor use. Here are the key steps:

  1. Make sure your plywood isn’t already waterproofed as this could save you a job. Ask at the shop you got it from if you’re not sure.
  2. Then give it a clean to get rid of any stains or dirt.
  3. Ensure it’s completely dry before you start.
  4. Apply a good quality waterproofing solution to the plywood in thin even layers
  5. Wait for it to dry
  6. Check the sealant has covered the full surface area of the plywood, if not repeat.

How to waterproof brick walls

Waterproofing brickwork is another job that’s important to do to protect your home. Once you know how it’s pretty straight forward. Here are some key tips for brick waterproofing:

  • There’s a variety of options for waterproofing exterior brickwork, from creams that soak into the bricks to silicone resins that form a protective seal.
  • If you’re not sure which is best, head down to your local DIY store to look at the different options and get specific advice on waterproofing brick walls and other features.
  • Once you’ve chosen your product, follow the instructions on the back of the pack. This will usually involve cleaning the brick wall first, then applying the sealant and waiting for it to dry.
  • If you’re using a product that you haven’t used before, we recommend patch testing first to check it is suitable for your wall.
When you’re working with bricks always be careful that the wall is secure and wear protective shoes to prevent any falling bricks causing injuries.

How to waterproof wood

Treating wood for outdoor use is an important part of garden maintenance. Whether it’s a wooden fence or seating arrangement, this is a pretty straightforward job once you know how. Here are the most important things to know:

  • Prepare the surface before you start. This involves giving it a good clean and waiting for the wood to dry.
  • Buy a good quality water-based wood sealer. These can be found at larger DIY shops.
  • Apply evenly with a soft-bristled brush
  • Leave it to dry and assess the effect. You may decide to do further coats depending on how much water is likely to get on the wood and the directions on the back of the pack. If so, repeat as above another two or three times.

Common errors and FAQs

  • Clean your garden features before waterproofing them otherwise you’ll lock in dirt and grime.
  • If you need to remove paint from brick or wood be sure to do so before you start waterproofing exterior brickwork or wood.
  • After waterproofing wood it takes a little time for the process to have an effect so build that into your project plan.
  • People often ask whether you can seal wood with oil. The answer is generally yes but it’s important to use a product designed for this, not just use the stuff you have at home.