There are different ways to waterproof a deck, and the best one for you will depend on the needs and features of your deck.
Different kinds of decks might need different ways to keep water out. For example, a concrete or composite deck may need a different approach than a wood deck.
Some systems for keeping water out may need more upkeep than others. For instance, coatings might need to be reapplied every so often to keep working, while membranes and underlayments might last longer.
The best deck waterproofing system will depend on your budget and what you want, as well as the needs and features of your deck. Research and talk to a professional to find the best solution. Some popular choices are:
Waterproof coatings
When applied as a liquid, these make a waterproof barrier on the deck’s surface. They can work to keep water from getting through the surface, but they may need to be reapplied from time to time to keep working.
Protecting the boards from the weather with stain or sealer can make the outdoor space last longer. The sealant keeps water from getting on the deck. You’ll need a pad with a built-in reservoir or a foam roller to use a sealer.
Spread a thin, even coat of high-quality, mold- and mildew-resistant, waterproof sealer with UV protection in the direction of the boards with a stain brush.
Waterproof membranes
These are put under the deck’s surface and make a barrier that keeps water from getting into the decking material. They are often put on top of the deck to protect it.
When it comes to keeping a uniform thickness, liquid-applied membranes are more sensitive to how they are applied than sheet membranes.
Waterproof coatings applied with a liquid are versatile and can be used for most waterproofing jobs.
A liquid waterproofing membrane for the wood deck should be put on in at least two coats. Most liquid membranes tell you how long you need to wait between coats.
Waterproof underlayment
This layer is put down under the decking, and it helps stop water from getting into the deck’s structure.
You must waterproof your deck to make the most of your outdoor space. It will keep water from ruining your space and give you a place to store things or hang out outside. It’s a no-brainer to waterproof the area under a second-story deck.
The most common way to keep water out of spaces below decks is to place plastic membranes in the spaces between the joists and decking to make troughs. A membrane-and-downspout system is the Trex RainEscape deck waterproofing system.
Drainage systems
These are made to move water away from the deck surface so it doesn’t pool, and the deck stays dry.
If you already have a drainage system, you can add a ceiling system or deck roof without worrying about keeping water out.
The under-deck drainage system does all the work. It removes the water on your decking and gives you a dry space with many great options.
The best way to ensure your whole deck stays dry is to install a drainage system when you build it. A drainage system on a deck keeps water from getting into the joists and beams.
This is possible with an under-deck drainage system and the space under your two-story deck.
Things to consider when choosing a deck waterproofing system
Look for a waterproofing system that will last and can handle rough weather.
When choosing a waterproofing system, think about how easy it is to use. Some systems may need to be set up by a professional, while others are easy for homeowners.
Figure out how much you can spend on the waterproofing system and look for a product in that price range.
Make sure that the waterproofing system you choose works with the material of your deck.
Look for a waterproofing system that comes with a warranty. This can give you peace of mind and protect you if the product isn’t as good as it should be.
There are many ways to make a deck waterproof, such as with coatings, membranes, and sealants. Think about which method will work best for you.
If looks are important to you, think about how the waterproofing system will look and how it will affect the look of your deck.
Some systems for keeping water out may need regular maintenance to keep working. When choosing a system, think about how much maintenance it will need.
If many people walk on your deck, you should choose a waterproofing system that can withstand wear and tear.
Think about the weather where your deck will be. If you live where it rains or snows a lot, you should choose a waterproofing system that is made for these kinds of weather.
Your deck will be healthier and last longer if it has enough airflow. Think about a waterproofing system that lets air flow so that moisture doesn’t build up and cause rot.
Think about the condition of the surface on which the deck will be built. If the base is in good shape, a coating may be all that is needed. If the substrate is in bad shape, a membrane may be needed to ensure the deck has a stable base.
If you think you might need to fix your deck in the future, choose a waterproofing system that is easy to fix.
If you think you might need to take the waterproofing system off at some point, choose one that is easy to take off without hurting the surface underneath.
Check the local building codes and rules to ensure that the waterproofing system you want is legal.