Is a moisture or vapor barrier required for vinyl flooring? (2024)

FAQs

Is a moisture or vapor barrier required for vinyl flooring? ›

Typically, moisture barriers are needed when vinyl flooring is installed on top of a concrete subfloor or crawl space. Please refer to the manufacturer guidelines, installation instructions, and warranty information for more details.

A moisture barrier helps control the water vapor's movement to help protect your floors. Therefore, if you're installing floors in an area that sees moisture, even a little, a vapor barrier is needed.

Is a vapour barrier necessary with all substrates? It's especially important to lay down a vapour barrier on mineral substrates such as concrete and screen, as they emit moisture. But installing a membrane is often also advisable on subfloors that look dry at first glance.

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.

Separate Underlayment. Laminate flooring manufacturers typically recommend an underlayment. What happens if you don't put padding under laminate flooring is moisture coming through the subfloor can cause it to warp and mildew. And footsteps on the floor will be louder.

Signs That Your Building or Home Needs a Vapor Barrier

Dampness in the basem*nt or crawl space indicate cracks in the foundation. High indoor humidity levels. Poor airflow or drafts from windows or doors indicate improper air circulation throughout a structure.

If the vinyl flooring product you choose doesn't have an attached underlayment, you can almost always install directly over the subfloor without one. But to maximize softness, warmth, moisture proofing, and noise reduction, an underlayment is key.

Luxury vinyl plank manufacturers mention only vapor barrier in their installations. They recommend this due to not allowing (concrete subfloor) getting moisture or alkalinity to your flooring choice.

There's no need for a moisture barrier underlayment on plywood. It's more important that the underlayment dampens sounds and feels comfortable.

Vapor Barrier (6 mil polyfilm) – Not Required

While this still might not protect you from flooding, it will protect you from chemicals/mold reaching your floor and causing havoc. Conclusion: We recommend to at-least install a 6-mil vapor barrier underneath.

When should you not use a vapor barrier? ›

Because a vapor barrier is a low permeable barrier, it keeps moisture from passing through. This is beneficial to keep moisture away from a dry surface but will trap moisture behind it if installed on a water-damaged concrete wall, causing the wall to fail further.

The Cons of Vapor Barrier Installation

Although vapor barriers aim to prevent moisture from entering the structure, they can also trap moisture inside. If not properly installed or upheld, this could result in the proliferation of mold and other issues related to moisture.

The Problem With Vapor Barriers

This can lead to significant moisture problems and mold; problems occur when walls get wet during construction or more often throughout the home's life. These wetting cycles can be from air flow, window leaks, pressure imbalances, and a host of lifestyle issues.

Recommended Materials for Vapor Barriers

Most home builders recommend at least 6–mil thickness. Plastic sheeting provides an effective air and moisture barrier, but the construction process can easily damage it. Plastic sheeting is not recommended for brick houses.

If your planks already have a pad-attached underlayment, you most likely won't need an underlayment. However, if your flooring manufacturers installation instructions allow for an extra underlayment, adding an extra underlayment will provide improved sound reduction, insulation, and moisture protection.

In short, vinyl flooring itself can be completely self sustainable and does not require an underlayment to function properly.

When you have a bump or dip in your subfloor, the uneven surface can cause vinyl planks click-lock-systems to become uneven. This will cause creaking or “popping” every time you walk over the floor. An underlayment can help fill in subfloor imperfections and leave your flooring a smooth surface to lay on.

Vinyl – the only flooring that doesn't require underlay

Due to its in-built cushioning, vinyl is capable of providing sufficient levels of thermal and sound insulation all on its own. Plus, it's already very soft and comfortable enough underfoot – therefore negating the need for an additional layer.

If installing your luxury vinyl plank flooring over an existing vinyl floor or tile then you won't need an underlayment. This is because other vinyl may be backed by a cushion and tile can build the necessary level to prevent needing another layer.

Unfortunately, even the most expensive and expertly installed vinyl floor can suffer harm from moisture. One of the problems we frequently hear from homeowners is having water under vinyl plank flooring. However, the resistance is eliminated by subfloor pipes which may have leakages to damage.