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.
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.
We would recommend an underlay of 3 – 5mm for laminate flooring. It should be at least 3mm thick to provide comfort and ground levelling properties. But, it should be no more than 5mm thick. If it's any thicker, you could experience problems with the laminate's locking system.
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.
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.
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.
An underlayment that offers a vapor barrier is essential to protect any flooring installed over a subfloor that emits moisture, like concrete. A thin foam underlayment made of polyethylene or polypropylene usually works best.
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.
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.
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.
In general, the underlay for laminate flooring is between 1mm and 3mm thick, while most carpet underlays are around 8mm to 10mm thick. This thick padding would not offer proper support to the laminated floors, possibly damaging your floors.
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.
When choosing an underlayment for vinyl plank flooring on concrete, it's best to pick an option that provides heat insulation and moisture regulation. Wood subfloors do an excellent job of regulating temperatures and controlling moisture, but they don't absorb sound, so a felt underlayment makes for a great pairing.
Moisture barrier underlayment acts as a blockade between the subfloor and laminate to protect your floor from any moisture damage. It really is as simple as it sounds!
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.
Don't install your laminate on any floor with a drain. Don't install laminate on any uneven subfloor or outdoors. Don't install your laminate over residential carpet. Don't install a second layer of laminate underlayment.
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.
Vinyl planks and tiles are one of the most cost-effective flooring options for installing directly over concrete or with a felt underlay. Vinyl flooring is manufactured from linoleum and is a practical, water-resistant option.
No, you should not glue down your underlayment. Underlayment is is a floating material, the same as your laminate flooring. In most cases, you should not glue or nail your underlayment down. You should always check with the installation instructions of the underlayment for proper installation instructions first.
Vinyl floors under 4mm should be installed right over the subfloor. If you have any areas on a concrete subfloor with moisture concerns, we recommend using a vapor barrier underlayment that will not add any cushion to the planks.
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.
Use a dehumidifier to remove moisture from the air and reduce the condensation. Use a penetrating sealer to seal the concrete and keep out moisture. We recommend using a concrete densifier first as a primer followed up by a penetrating concrete sealer.
However, you will need an underlay for lino flooring on concrete on the form of a thin vapour barrier to protect it from moisture. To install your underlay, measure how much you need and cut the underlay into strips, add at least 5cm extra to give yourself some space.