Do Vinyl Plank Floorings Need Underlayment?
Installing vinyl plank flooring can transform the look and feel of any room. With realistic wood and stone designs, vinyl planks offer style and durability at an affordable price point. But before starting your vinyl plank installation, an important question arises: do you need underlayment?
Underlayment refers to a thin padding layer installed underneath vinyl planks to help provide insulation and sound dampening. Let's look at the pros and cons of using underlayment for vinyl plank flooring.
Purposes of Underlayment
Underlayment serves several key purposes for vinyl plank flooring:
- Moisture protection - Underlayment creates a moisture barrier between the vinyl planks and substrate.
- Thermal insulation - It helps regulate temperatures, preventing cold transfer.
- Sound absorption - Underlayment dampens noise from footsteps and dropped items.
- Levelling - It can smooth over minor subfloor imperfections.
- Cushioning - Underlayment adds softness and comfort underfoot.
These benefits make a compelling case for using underlayment in most vinyl plank installations. However, underlayment may not be required in all situations.
When is Underlayment Recommended?
There are three main types of subfloors where underlayment is highly recommended for vinyl plank installations:
Concrete Subfloors
Concrete naturally absorbs moisture from the ground and air, secreting it as vapor emissions. This moisture can damage vinyl flooring over time, causing planks to warp, buckle and discolor. Underlayment creates a protective barrier.
Look for underlayments with high moisture resistance like cork, rubber, or recycled fibers. Many experts also advise installing a polyethylene plastic moisture barrier below the underlayment for added vapor protection.
The thermal insulating properties of underlayment are also important for concrete subfloors. Concrete readily conducts cold, creating cooled floor surfaces. Quality underlayment insulates the flooring and brings it to room temperature.
Plywood and OSB Subfloors
On upper levels of a home, underlayment helps muffle noise from footsteps, furniture shuffling, and other impacts. This is particularly important for multi-level houses with bedrooms below the vinyl flooring.
Rubber, cork, and high-density foam underlayments provide excellent sound insulation. The material density, thickness, and compression strength all contribute to noise reduction performance.
Underlayment also smooths over inconsistencies in the subfloor, preventing them from compromising the vinyl plank installation. Nails, joints, cracks, and other imperfections are concealed.
Existing Tile Flooring
When installing vinyl planks over existing ceramic, porcelain or natural stone tile, underlayment can conceal grout lines and provide cushioning. Without underlayment, grout lines may telegraph through the new flooring.
A thin 1-3 mm underlayment prevents grout show-through. Rubber and cork underlayments work well for tile substrates. If the tile floor feels cold, thermally insulating underlayment can add warmth.
Types of Underlayments
There are several common underlayment materials, each with pros and cons:
- Felt - inexpensive option offering basic sound insulation
- Cork - naturally moisture resistant, anti-microbial, and sound absorbing
- Foam - range of densities for cost/performance options
- Rubber - excellent moisture barrier and noise reduction
Key factors for choosing underlayment type include price, acoustics needs, and moisture resistance. Always check vinyl plank flooring manufacturer recommendations for best underlayment pairing.
Felt Underlayments
Felt underlayments, made from recycled fibers, are a budget-friendly option. While moisture resistance is low, felt offers moderate sound insulation. It smooths over minor subfloor imperfections.
On the downside, felt compresses easily so it provides less underfoot cushioning over time. It may not adequately insulate cold, hard substrates.
Cork Underlayments
Cork underlayment offers natural moisture resistance along with anti-microbial and sound absorbing properties. Made from recycled cork oak tree bark, it's an eco-friendly choice.
Cork has good compression strength for steady cushioning. Its insulation properties also help moderate cold from concrete floors. The main downside is that natural cork has a weaker moisture barrier compared to synthetic options.
Foam Underlayments
Polyurethane and recycled rubber foam underlayments provide a wide range of price points and performance. Low density foams are affordable but compress easily. High density options offer sturdier cushioning and better moisture resistance.
Foam underlayment ranges from 1 to 7 mm in thickness. Thicker options provide more sound insulation. Consider foam density and thickness in relation to flooring needs and budget.
Rubber Underlayments
Rubber underlayments offer premium performance for both sound insulation and moisture resistance. Recycled rubber has dense properties along with durability and longevity.
Rubber barriers provide excellent protection from moisture emissions. They also have sound dampening properties, enhanced by thickness and density. This makes rubber one of the best choices for concerts substrates like concrete.
Installation Tips for Underlayment
Proper underlayment installation ensures your vinyl plank flooring gets the full performance benefits.
Allow for Expansion Gap
Leave a small 3-5 mm gap around the perimeter of the room when installing the underlayment. This allows the finished floor to expand and contract with temperature changes. Do not install underlayment flush to the walls.
Seal Seams
Use seam tape or caulk to seal joints between underlayment sheets. This prevents moisture seepage between sections, which could spread underneath and damage the planks.
Follow Flooring Direction
Install underlayment at a 90 degree angle to the direction of the vinyl planks. This makes for smoother transitions between underlayment sheets beneath plank seams.
Ideal Thickness
Choose an underlayment thickness between 2-4mm. Thinner than 2mm offers less sound insulation and compressive strength. Over 4mm may allow imperfections to telegraph through to the vinyl floor surface.
Tape Perimeter
Apply adhesive tape around the edges of the underlayment to hold it firmly in place. Without taping, the underlayment can shift during plank installation and bunch up.
When Underlayment May Not be Needed
There are some instances where underlayment may not be required:
- Installing over a single layer of existing vinyl flooring
- Installing over a cleanly prepped wood subfloor on a ground level
- Installing in a garage, basement, or utility area
Existing vinyl layers or wood subfloors on ground levels have less moisture concerns. Garages and basements often prioritize utility over insulation needs.
However, while underlayment may not be an absolute necessity in these cases, it can still provide useful benefits like sound insulation and comfort underfoot. Weigh your needs and budget when deciding.
Underlayment is highly recommended for most vinyl plank flooring installations, especially over concrete, upper level subfloors, or existing tile. It offers many performance benefits.
However, underlayment may not be strictly necessary in every situation. For lower moisture installations on a single ground level, the added cost of underlayment could potentially be skipped.