Without waterproofing, water will eventually seep through grout lines and cracks in tiles, which can lead to serious structural issues. While you may not have to waterproof your whole bathroom floor, it is always ideal for the additional layer of protection and to ensure no damage to your property.
You can seal a subfloor using a sealant specifically designed for subfloors, such as a penetrating sealer or a moisture barrier. Penetrating sealers are typically made from a wax or oil-based formula that soaks into the wood, protecting it from moisture and rot.
Importance of Waterproofing
Bathrooms are high-moisture environments, and without proper flooring, water can seep into the subfloor and beyond, causing significant damage over time.
Yes, a moisture barrier is recommended on a wood subfloor to prevent moisture from seeping into the flooring material, which can cause warping, mold, or mildew. It is especially crucial in areas prone to high humidity, such as basements or bathrooms.
Latex-based or polyurethane-based paint is one of the most accessible forms of waterproofing plywood. There are plenty of colours to choose from, which can be applied using a spray gun or painted with a roller. You must apply two to three coats of paint for maximum effectiveness.
Plywood needs to be sealed before using it outdoors, or in high moisture areas such as bathrooms and kitchens. This is because plywood is not waterproof or rot resistant, and it is at risk of warping, splitting or degrading over time.
Subflooring in the kitchen and bathroom may also be pressure treated since water leaks are common in these rooms and subflooring is inaccessible to the residents.
Subfloor Material
Therefore, because concrete is porous, it's a good idea to install a vapor barrier over your concrete subfloor before installing your flooring. This way you can stop the vapor drive of water upward to your floors, protecting them from any damage (source).
Cement-Based Backer Board
It is generically called cement-board or backer board, or it can also be referred to by one of the common brand names, such as DensShield, Hardiebacker, and WonderBoard.
The minimum requirements are: The entire floor should be waterproofed for the shower area, and the shower walls need waterproofing up to 1800mm. Bathroom walls need waterproofing up to 150mm. For wooden bathroom floors or bathrooms on higher levels, the entire bathroom floor needs waterproofing.
Sealing tiles and grout reduces the porosity of the materials and protects the tiled surface, increasing its resistance to dirt, spills, staining and general wear. Sealing tiles and grout means they will last longer, look better and be easier to keep clean.
In terms of withstanding moisture and humidity, luxury vinyl tiles (LVT), vinyl roll, and porcelain or ceramic tile are the best bathroom flooring options. Each of these flooring options is water-resistant and able to withstand humidity and temperature changes in a bathroom.
Cement board is best suited for: Ceramic and Porcelain Tile: Cement board is specifically designed to be a moisture-resistant substrate for tile in high-moisture areas like bathrooms and kitchens.
Underlayment is the material placed on top of the subfloor that assists in the installation of the tile or other type of flooring.
One solution to help protect the sub-floor from rainwater damage during construction is to use LP® TopNotch® 350 Durable Sub-Flooring. What is LP TopNotch 350 Durable Sub-Flooring? LP TopNotch 350 Durable Sub-Flooring is an OSB sub-flooring designed to reduce the impact of moisture during construction.
Assuming your subfloor is in good shape and level, your next step is waterproofing. Use a layer of unmodified thin-set mortar on your substrate, then add an uncoupling membrane, like Schluter®-DITRA & DITRA-XL. Then add another layer of thin-set mortar on top of the membrane, and finally, you place your tiles.
Install an intervening sheet of thinner plywood on top of the subfloor plywood. Do not install tile directly on the plywood subfloor itself.
Luxury Vinyl Tile (LVT) is a superstar when it comes to small bathroom remodels. Why? Because it offers the look of natural stone or wood, without the high maintenance or cost. LVT can be waterproof, durable, and incredibly easy to clean—a must for any bathroom.
Yes, sealing the plywood subfloor ensures better adhesion for peel-and-stick tiles and prevents moisture damage. Use a primer or sealer designed for flooring to create a smooth, even surface. This also extends the lifespan of the tiles by enhancing their bond.
Both are designed to keep moisture out of your home and can be made from various materials. But there are a few key differences, the most apparent being that moisture barriers are better at keeping out liquids, and vapor barriers are better at keeping out water in its gaseous state.
The first way that you can fix a subfloor moisture problem is by removing the finished floor and exposing the subfloor. Make sure that an HVAC system is installed or use a dehumidifier, and then, let the subfloor dry until the moisture levels have gone down.
Both plywood and OSB are effective choices for your subfloor needs. Plywood is a better option for projects that require a lot of cutting and molding, while OSB is a good option for those who need to cover areas where moisture exposure may be an issue.
The most common ways of waterproofing plywood include treating the wood with epoxy, waterproof glue sealant, or polyurethane prior to installation.
Pressure treated plywood can be used on its own as it is water resistant and will withstand the humid temperatures that are common in bathrooms.