How To Level Vinyl Plank Flooring

Vinyl plank flooring is a popular choice for homeowners due to its durability, water resistance, and aesthetic appeal. However, a successful vinyl plank installation relies heavily on having a perfectly level subfloor. Uneven subfloors can lead to several problems, including unsightly warping, premature wear and tear, and even compromised interlocking systems. Therefore, understanding how to level a subfloor before installing vinyl plank flooring is crucial for a long-lasting and visually pleasing result. This article provides a comprehensive guide to leveling a subfloor in preparation for vinyl plank installation.

Before embarking on any leveling project, a thorough assessment of the subfloor is essential. The type of subfloor (wood, concrete, or existing flooring) will dictate the techniques and materials used for leveling. Additionally, identifying the severity and extent of the unevenness is critical for choosing the appropriate leveling method. Small imperfections may require a different approach than widespread or significant dips and humps.

Assessing the Subfloor for Unevenness

The first step in leveling preparation is to meticulously inspect the existing subfloor. This assessment will reveal the extent of the problem and influence the choice of leveling method. This process involves both visual inspection and the use of leveling tools.

A visual inspection can reveal obvious issues such as cracks, holes, or loose boards. Paying attention to areas where the floor appears to dip or rise is essential. Look for signs of water damage, which can exacerbate unevenness. Furthermore, observe the overall condition of the subfloor. Is it clean and free of debris? Are there any protruding nails or screws that need to be addressed? Are there signs of mold or mildew that need to be eradicated before continuing?

For a more precise assessment, a long, straight edge, such as a six-foot level or a long metal ruler, is necessary. Place the straight edge on the subfloor in several locations, both lengthwise and widthwise. Use a smaller level to check if the straight edge is perfectly level. If there are gaps between the straight edge and the subfloor, measure the gap at its widest point. These measurements will help determine the severity of the unevenness. Mark the locations of these gaps with a pencil or masking tape for later reference. For larger areas, consider using a laser level to identify high and low spots quickly and accurately. The laser level projects a level line across the entire room, making it easier to identify discrepancies.

When dealing with concrete subfloors, look for cracks and spalling (surface chipping). Concrete can also develop high spots from improper pouring or settling. Use a concrete grinder to remove any high spots, ensuring a smooth transition to the surrounding areas. For wood subfloors, check for loose or damaged boards. Replace any boards that are rotted or weakened. Secure any loose boards by driving screws into the joists below.

It is worth noting that building codes often specify allowable variations in subfloor levelness. Consult local building codes to ensure that the leveling process meets the required standards. Addressing these issues before installing the vinyl plank flooring will prevent future problems and ensure a professional-looking result.

Leveling Methods: Patching Compounds and Self-Leveling Underlayment

After thoroughly assessing the subfloor, the next step involves choosing an appropriate leveling method. Two common methods are using patching compounds for localized imperfections and self-leveling underlayment (SLU) for larger areas or more significant unevenness. The choice between the two depends on the nature and extent of the leveling required.

Patching compounds are best suited for filling small gaps, cracks, or minor depressions in the subfloor. These compounds are typically a mixture of cement or gypsum with additives that improve adhesion and workability. They are applied directly to the imperfections, creating a smooth and level surface.

To use a patching compound effectively, first, clean the area to be patched thoroughly. Remove any loose debris, dirt, or dust. Applying a bonding agent can improve the adhesion of the patching compound to the subfloor. Follow the manufacturer's instructions for mixing and applying the patching compound. Typically, the compound is mixed with water to a consistency similar to peanut butter. Use a putty knife or trowel to apply the compound to the imperfection, ensuring that it completely fills the gap or depression. Feather the edges of the patch to blend seamlessly with the surrounding subfloor. Allow the patching compound to dry completely according to the manufacturer's instructions before proceeding with the vinyl plank installation.

Self-leveling underlayment (SLU) is a pourable mixture designed to create a smooth, level surface over larger areas or when dealing with more significant unevenness. SLU is typically a cement-based or gypsum-based mixture that flows freely and seeks its own level. It is an excellent option for correcting larger dips, uneven transitions, or entire rooms with sloping floors.

Preparing the subfloor for SLU is crucial for a successful application. Start by cleaning the subfloor thoroughly. Remove any loose debris, dirt, or dust. Apply a primer specifically designed for use with SLU. The primer helps the SLU adhere to the subfloor and prevents the formation of air bubbles. Seal any cracks or holes in the subfloor to prevent the SLU from leaking through. This can be done with patching compound or a specialized crack sealant. Install damming around the perimeter of the room to contain the SLU. This can be done with foam strips, wood strips, or other suitable materials. Follow the manufacturer's instructions for mixing the SLU. The consistency should be thin enough to flow easily but not so thin that it becomes watery. Pour the SLU onto the subfloor, starting in the deepest areas. Use a gauge rake or smoother to distribute the SLU evenly and ensure that it flows into all areas. Spike the SLU with a spiked roller to release any trapped air bubbles. Allow the SLU to dry completely according to the manufacturer's instructions before installing the vinyl plank flooring. This can take several days, depending on the thickness of the SLU and the ambient humidity.

When choosing between patching compound and SLU, consider the size and severity of the unevenness. For small, localized imperfections, patching compound is a cost-effective and convenient solution. For larger areas or more significant unevenness, SLU provides a more comprehensive and effective leveling solution. Always follow the manufacturer's instructions for the specific product being used to ensure proper application and performance.

Alternative Leveling Methods: Using Shims and Underlayment

While patching compounds and self-leveling underlayment are common and effective leveling solutions, alternative methods such as using shims and underlayment can also address uneven subfloors. These methods are often used in conjunction with other leveling techniques to fine-tune the surface before installing vinyl plank flooring.

Shims are thin, tapered pieces of wood or plastic used to fill gaps and create a level surface. They are particularly useful for addressing localized dips or unevenness, especially when dealing with wood subfloors. Shims can be used to level individual floorboards or to correct minor variations in height across a larger area.

To use shims effectively, identify the low spots on the subfloor using a straight edge and level. Place the shims under the low spots, gradually increasing the thickness until the surface is level. Secure the shims to the subfloor with construction adhesive or screws. Be careful not to overtighten the screws, as this can damage the shims or the subfloor. Trim any excess shim material that protrudes beyond the surface of the subfloor. This can be done with a utility knife or a saw. Sand the shims smooth to blend them seamlessly with the surrounding subfloor. While shims can be beneficial for spot-leveling, it is important to note that using too many shims or shimming over a large area can create an unstable foundation for the vinyl plank flooring. Therefore, shims are best used for minor corrections in conjunction with other leveling methods.

Underlayment is a thin layer of material placed between the subfloor and the vinyl plank flooring. It provides a smooth, consistent surface for the flooring to rest on and can help to cushion the flooring, reduce noise, and improve insulation. While underlayment alone cannot correct significant unevenness in the subfloor, it can help to smooth out minor imperfections and provide a more level surface for the vinyl plank flooring.

There are various types of underlayment available, including foam, cork, and felt. The choice of underlayment depends on the specific needs and preferences of the homeowner. Foam underlayment is a popular choice for its cushioning properties and ease of installation. Cork underlayment is a natural and sustainable option that provides excellent sound insulation. Felt underlayment is a dense and durable option that provides good support for the flooring.

To install underlayment, roll it out over the subfloor, ensuring that it covers the entire area to be floored. Overlap the edges of the underlayment slightly and tape them together with seam tape. This will prevent the underlayment from shifting during installation. Trim any excess underlayment material that extends beyond the edges of the room. While underlayment can help to smooth out minor imperfections, it is not a substitute for proper subfloor preparation. Significant unevenness must be addressed using other leveling methods before installing the underlayment.

In summary, while patching compounds and self-leveling underlayment are the primary methods for leveling subfloors, shims and underlayment can be used to supplement these methods and fine-tune the surface before installing vinyl plank flooring. Careful assessment of the subfloor and selection of the appropriate leveling methods are crucial for a successful and long-lasting vinyl plank flooring installation.