Yes, you can use underlayment for vinyl plank flooring, but the necessity and type depend on several factors, including the specific vinyl product and your subfloor conditions. Many modern vinyl planks, particularly rigid core types like Stone Plastic Composite (SPC) and Wood Plastic Composite (WPC), often come with an integrated padding. Even with an attached pad, a separate underlayment can offer additional benefits or address specific subfloor issues.
Vinyl Plank Flooring’s Design and Underlayment’s Purpose
Vinyl plank flooring (VPF) is engineered for durability and often features an attached underpad, especially in rigid core varieties such as Stone Plastic Composite (SPC) and Wood Plastic Composite (WPC). This integrated pad provides basic sound dampening, minor comfort underfoot, and sometimes a moisture barrier. While this built-in layer can be sufficient, adding another underlayment might void the manufacturer’s warranty if it’s too thick or soft, potentially compromising the flooring’s locking mechanisms.
Underlayment is a layer of material placed between the subfloor and the finished flooring. Its primary functions include providing a smooth surface, acting as a moisture barrier, reducing noise, offering thermal insulation, and enhancing underfoot comfort. The decision to use a separate underlayment with VPF depends on whether the VPF already includes an attached pad and what additional performance enhancements or subfloor solutions are desired.
Scenarios Where Underlayment is Beneficial
Underlayment can bridge minor subfloor imperfections, creating a smoother surface for vinyl planks. This helps prevent VPF from flexing or separating at the joints if the subfloor is not perfectly flat. While underlayment aids minor irregularities, it is not a substitute for addressing significant subfloor issues.
A vapor barrier is a significant benefit of certain underlayments, especially over concrete slabs or in moisture-prone areas. Concrete can allow moisture to rise, potentially leading to mold or damage. Underlayments with integrated moisture barriers protect against this transfer.
Underlayment significantly reduces both impact sound (like footsteps) and airborne noise (such as voices). This is advantageous in multi-story buildings or apartments, where sound transmission between floors is a concern. Underlayment creates a barrier that absorbs sound, contributing to a quieter environment.
Underlayment can provide an additional layer of thermal insulation, making the floor feel warmer, especially over cold subfloors like concrete. This insulating property helps maintain room temperature and can contribute to energy efficiency. The added cushioning also provides a softer, more comfortable feel underfoot, which can be desirable in living spaces.
Selecting the Right Underlayment Material
When selecting underlayment for VPF, suitable types include closed-cell foam, cork, and felt. Closed-cell foam offers sound insulation and comfort. Cork provides excellent soundproofing, thermal insulation, and resistance to mold and mildew. Felt, often made from recycled materials, is known for noise reduction and slight cushioning.
Checking the VPF manufacturer’s warranty and recommendations is important. Some manufacturers specify acceptable underlayment types or disallow additional underlayment, especially if planks have an attached pad. Overly soft or thick underlayment can compromise the VPF’s click-lock system, leading to instability or gapping.
Underlayments come with specific features, such as integrated vapor barriers or sound ratings. Impact Insulation Class (IIC) measures impact noise blockage, while Sound Transmission Class (STC) measures airborne noise reduction; higher ratings indicate better performance. Some underlayments are also designed for compatibility with radiant heating systems. Certain materials, like very soft foam or some rubber underlayments, should generally be avoided unless explicitly approved by the flooring manufacturer.
Key Installation Considerations
Before installing underlayment and VPF, the subfloor must be clean, dry, and level. Remove any debris, dust, or adhesive remnants. Minor imperfections can be addressed with underlayment, but significant unevenness (more than 1/8 inch over a 6-foot span) requires subfloor repair with leveling compounds.
Proper underlayment installation includes ensuring seams are butted together and sealed, often with tape. Lay the underlayment perpendicular to the VPF planks. Leave a small expansion gap, typically 1/4 inch, around the room’s perimeter to accommodate slight movements. These steps help maintain the moisture barrier’s integrity and the flooring system’s stability.
Following the installation instructions from both the VPF and underlayment manufacturers is paramount. Adhering to these guidelines ensures optimal performance. Incorrect installation, such as using an incompatible underlayment, can lead to issues like buckling, gapping, or moisture problems, compromising the flooring’s longevity.