In a bathroom, you need to use a 100% waterproof, mold-resistant underlayment or a specialized moisture barrier beneath your vinyl flooring. Popular moisture-resistant options include rubber, closed-cell foam, or cork (if properly sealed). Plywood is recommended if you need to create a new subfloor.
Water vapor can cause serious damage to your home. For instance, if your flooring gets wet, it could cause mold and mildew, and even destroy your floor (source). No one wants that, so vapor barriers are there to help prevent the floor from getting wet.
Yes, you can install vinyl flooring directly over a plywood subfloor, provided the plywood is clean, structurally stable, and completely flat. Because vinyl is flexible, any bumps, dips, or gaps will eventually telegraph through and become visible on the surface.
A foam underlay that includes a damp-proof membrane is a fantastic choice, especially if the subfloor is concrete or prone to moisture. The membrane protects your flooring from dampness while the foam provides a touch of cushioning. If your subfloor has minor imperfections, fibreboard underlay can smooth things out.
The LVP plank itself is 100% waterproof. The system, however, is only as water-tight as its installation. This is the most important distinction to understand. Thinking about your floor as a complete system is crucial for success in kitchens, bathrooms, and basements.
Common Mistakes When Installing Vinyl Plank Flooring
Short answer: yes, mould can grow under vinyl flooring — but only when moisture gets trapped between the planks and the subfloor. Vinyl itself is non-porous, so the planks don't host mould.
Any vinyl flooring that's installed directly to the subfloor, such as sheet vinyl or dryback LVT, doesn't need underlay. However, floating floors like click LVT, will require underlay (if it isn't already built-in).
Thicker isn't always better when it comes to LVP underlayment. Many manufacturers specify a maximum thickness (often around 1.5mm–2mm) to ensure the floor's locking system remains tight and stable. Too much cushion can cause joint separation over time. 1mm–1.5mm: Best for floors with pre-attached padding.
Yes, you can install vinyl flooring directly over concrete, making it an excellent and highly durable choice. However, concrete is porous and prone to moisture, so proper prep work and moisture barriers are essential to prevent mold, warping, or damaged seams.
Between the subfloor and vinyl flooring, you should either install a dedicated vinyl underlayment, a moisture barrier, or simply a floor leveling patch. The exact material needed depends entirely on your specific vinyl type and whether your vinyl planks have padding pre-attached to the back.
😂 Pro tips: When using permanent vinyl on wood, make sure to sand the surface of your wood and seal it with either varnish or a sealing agent like mod podge to give your permanent vinyl a smooth surface to cling on. Your permanent vinyl will not cling properly if your wood is raw, unsealed and has lots of debris.
For the best results with vinyl flooring, use 14one-fourth𝟏𝟒-inch or 38three-eighths𝟑𝟖-inch exterior-grade plywood (such as AC or BC grade), or premium specialty underlayments like SurePly Underlayment. These provide a smooth, strong, and moisture-resistant surface that prevents telegraphing (showing seams or dents) and protects your vinyl warranty.
Yes, a vapor barrier is highly recommended—and often necessary—between concrete and vinyl flooring to prevent moisture damage, mold, and to protect your warranty. Concrete is porous and constantly releases moisture vapor, which can become trapped under vinyl, leading to cupping and joint failure.
Yes, you can install Luxury Vinyl Plank (LVP) directly over plywood. However, because LVP is flexible and conforms to the shape of the surface beneath it, proper preparation is essential to prevent bumps, squeaks, or separated seams.
Most modern vinyl flooring, such as COREtec or Happy Feet, comes with an attached underlayment or pad, often with a moisture barrier built-in – unless the pad is cork. If the product you choose doesn't have an attached underlayment, you can almost always install directly over the subfloor without one.
Preparation Mistakes That Lead to LVP Installation Failure
Any uneven spots, old adhesive, or leftover debris from an existing floor can transfer through luxury vinyl or stress the locking system. The result is a floor that moves, clicks, or separates. Moisture conditions matter as well.
6–12 mil wear layers are best for light residential use, guest rooms and low-traffic areas. 12–20 mil is ideal for busy homes with kids and pets, your everyday family use. 20+ mil is where you enter light commercial territory, rental properties, small shops, and offices.
1/2" plywood is too thin for most subfloor applications and will flex or sag, especially if joist spacing is 16 inches or more. This can lead to squeaky floors and structural issues. -> The minimum recommended is 5/8" plywood, but 3/4" is preferred for strength and long-term durability.
The best underlay for vinyl flooring is a high-density, thin (1 to 1.5 mm) underlay, such as specialized QuietWalk Luxury Vinyl Underlayment. Because vinyl is already a thin, resilient material, you must avoid thick, spongy pads. Too much cushion causes the interlocking seams to flex and break under foot traffic.
In addition to being moisture resistant, vinyl is also stain resistant and can dampen noise. This often makes it a preferred flooring choice for families with children and pets. For these same reasons, many people choose to install vinyl plank flooring in bathrooms and basements.
CDX Plywood
Acceptable for bathroom subfloors in less visible areas or under heavy finish layers, but only if it is properly sealed and protected. CDX is less ideal than exterior-grade plywood but still usable in budget builds.
Yes, Dawn dishwashing soap can be used to clean luxury vinyl plank flooring. Just add a few drops to a bucket of warm water. This mixture is excellent for removing grease and grime, especially in kitchens. However, be cautious not to use too much soap, as it can leave a film that dulls the floor's shine.
Luxury Vinyl Plank (LVP) flooring typically lasts 15 to 30 years, depending on the quality of the planks, the thickness of the wear layer, and foot traffic.
Dust, adhesive residue, and paper-backed underlayment can all feed mold under your floor. Add trapped moisture and a warm room, and mold can start forming fast. According to FEMA, mold can begin growing on damp surfaces in as little as 24 to 48 hours. That's why what happens before your vinyl goes down is so important.