If you're installing laminate flooring over a subfloor, like concrete, you may want to install an underlay with a vapor barrier for added protection against moisture. Make sure you choose an underlay that works with an attached pad. Our top choice is Sentinel Protect Plus Underlayment.
While there are a number of good options in the market, cork and foam are the usual favorites for a laminate floor underlay. Depending on your lifestyle, you may appreciate cork for its thickness and sound absorption; foam, on the other hand, is an excellent, cost-efficient material that works as a moisture barrier.
Do you need underlay for laminate flooring on concrete? Yes, you definitely need underlayment when installing laminate flooring on concrete (or any other surface, for that matter). Laminate is a “floating floor” which means that it is not nailed or glued to the surface.
You'll typically need a vapor barrier if you're installing flooring over concrete. Therefore, in high-humidity areas, moisture will move to a relatively low-humidity area, even through concrete.
Foam underlay comes in rolls and is a great entry-level choice for your new floors. It's affordable and is ideal for laying over all types of subfloors. For concrete subfloors, make sure you opt for an underlay that has a vapour barrier to prevent damp from affecting your floors.
The American Concrete Institute (ACI) also recommends a minimum of 10 mil polyethylene or thicker for vapor retarders under concrete. According to its Guide to Concrete Floor and Slab Construction ACI 302.1R-15, thicker poly provides a better barrier and is also more puncture resistant.
The best materials for floor underlayments include foam, cork, and polyethylene (thermoplastic). If you're looking to add softness while absorbing sound and preventing mold and mildew, cork might be your best bet. 4 If your main goal is to add a moisture barrier, polyethylene might be a better choice.
Begin installation by laying a plastic vapour barrier (minimum 6 mm thick) or any other manufacturer-recommended barrier on the concrete subfloor to prevent moisture from reaching the laminate flooring. Use vinyl tape to secure the barrier and keep it from coming out.
Without underlayment to add a layer between these damp subfloors and the surface flooring, your laminate can quickly become wet, warped, and mildewy, harming its overall integrity. Moisture over time can also break down floor adhesive which causes the floor to start warping.
Most building codes require that floors above the ground level have an underlayment as sound insulation. A moisture barrier for hardwood floors prevents water from damaging the floor, especially if it is on a concrete slab or exposed below like an open crawl space.
Install a plastic vapor barrier: If your concrete passes the moisture test, then plastic sheeting at least 6 mils thick will prevent moisture from getting into your laminate flooring. Where plastic sheets must be joined, overlap the sheets by several inches, and use strong vinyl tape to secure them.
Laminate ranges from 6-mm to 12-mm and, as a rule, it shouldn't be less than 8-mm. If, however, budget is an issue and if your subfloor is level and debris-free, you might be able to get away with 7-mm; keep in mind that subfloor imperfections can telegraph to the surface floor, so make sure it's okay.
In the end, it's your decision if moisture protection and getting higher sound absorption is your goal. If not, then pre-attached underlayment will do it's job but at the minimum.
Laminate is highly water-resistant, making it ideal for installing over concrete as well as in areas susceptible to moisture like basements and kitchens. We recommend placing a vapour barrier underneath laminate flooring for an extra layer of protection.
Vapour barriers are materials used for damp proofing. The best approach is to lay a sheet (also called a membrane) of PE plastic 0.2mm thick beneath laminate flooring. Sheets are available in different sizes. A single sheet measuring four by four metres is large enough to cover most rooms.
In some cases, there may be an issue with the concrete subfloor, such as water damage or uneven flooring. This can result in moisture building up under the laminate floor and causing mold growth on the underside of the planks.
In short, yes. It's a misnomer that Luxury Vinyl Planks do not need a moisture barrier. If you are putting this type of flooring over your concrete and the contractor does NOT do a moisture, calcium chloride or RH test on your concrete, then they must put a moisture barrier down.
Even if the concrete foundation is enough to keep water away from the building, water vapor can easily rise to the surface and damage a building's foundation, subfloor, and main floor. A vapor barrier is crucial to protect a building from the many negative effects of water vapor on building materials.
You need a dry, clean and flat surface before you can install finished flooring in a room built on a concrete slab. One of the simplest options is a sleeper-based subfloor. The result is a subfloor that protects finished flooring from cold and damp concrete-based floors.
Start by sealing the surface of the concrete with a chemical sealing agent that will create one more barrier between the base of the laminate, and any groundwater that may seep up over time. Then, lay a 6-mil plastic moisture barrier underlayment to further protect the material.
As a rule, carpet underlay needs to be soft and comfortable to walk across to help cushion your steps, whereas hardwood flooring underlay, such as for wood floor underlay, tends to serve as a moisture barrier. Some flooring materials, like vinyl, may not even need underlay at all.
Concrete subfloors are very hard, so they require additional cushioning from soft underlayments made from foam, felt, or cork. When choosing an underlayment for vinyl plank flooring on concrete, it's best to pick an option that provides heat insulation and moisture regulation.
Sealers should be applied after pouring to help prevent water from coming into contact with the slab and provide protection against staining. The sheeting or membranes should be placed between the soil and the slab before the concrete is poured so that water does not come into contact with the surface of the slab.
The application of vapor barrier in exterior concrete is unnecessary due to the fact that water penetration does not matter. Any slab on grade that is enclosed and on the interior of a building should have a vapor barrier installed prior to pouring concrete, especially if flooring will be applied.