The foundation on which you are laying new flooring matters. The smoother and cleaner the substrate surface, the better. The quality and shape of the subfloor affect the flooring outcome, but waterproof rigid core SPC and WPC floors with attached underlayment help overcome problems with subfloors that may not be in the best condition. The attached underlayment is pliable, which helps hide minor - MINOR - subfloor imperfections like small cracks in a concrete slab for instance.

Underlayment is a layer of material or padding that goes between the subfloor and the LVT or LVP flooring. In this case we are talking about an underlayment that is pre-attached to the underside of the plank or tile at the factory during manufacturing.

Materials

There are a variety of types of underlayment materials:

• Polyethylene (PE) and polyurethane (PU) foam
• Natural material (cork)
• Recycled material, e.g., tires, felt, foam

There are advantages and disadvantages of these types of attached underlayment, but typically the PE foams are most used because they are waterproof.

Some underlayment reduce sound and are certified safe and clean for home indoor air quality (IAQ). Others are specifically designed to be installed over existing surfaces and smooth out subfloor imperfections. Look for products with the ASSURE CERTIFIED™ designation to provide confidence that material in the underlayment is safe for use in your home or business.

Sound absorption is one of the key benefits of attached underlayment and it is particularly important in multilevel homes or businesses. Sound transmission from one floor to the floor underneath is generally what is measured when it comes to flooring, and certain building codes must be met for multilevel buildings. The minimum amount of sound that must be blocked is 50 decibels (db). The two test results are technically referred to as STC and IIC. Note that the results of the tests can vary depending upon the construction of the ceiling of the lower room.

STC – Ambient Sound Transmission

STC measures the amount of ambient sound in an upper floor room is blocked from transmitting to the room directly underneath on the floor below. Ambient sound would be things like talking, music playing, etc.

IIC - Impact Sound Transmission

Impact Sound Transmission refers to the noise from people walking on or dropping something on the floor. The higher the rating indicates that more impact sound is blocked from transmitting through the floor into the room below.

Comfort and Warmth

Attached underlayment provide added comfort underfoot, which is especially important to people with joint problems or arthritis and in applications like retail stores and restaurants where associates spend a good deal of time on their feet. The underlayment also helps the floor retain heat making it feel warmer than a material like stone or ceramic tile. Many manufacturers allow their rigid core floors with attached underlayment to be installed over certain types of underfloor radiant heating systems. Be sure to check with the manufacturer for which types are allowable since they could vary from brand to brand.

Clean and Safe Material

Any product you bring into your home should be clean and safe for you and your family. Ask your retailer for ASSURE CERTIFIED™ rigid core floors that are tested to be safe for Indoor Air Quality (IAQ) and free of phthalates and heavy metals.

Thickness of Attached Underlayment/Pad (1 – 1.5 mm)

Attached underlayment can vary in thickness, but 1.0mm and 1.5mm are the two most common. While the same amount of material is used to make both thicknesses of underlayment, 1.0 mm is more compressed, making it denser and thus providing better sound absorption. 1.5 mm is less dense but provides more resilience and better comfort. You just need to weigh which is more important. In reality the typical homeowner will not notice a difference, and in a lot of cases, it’s not something you have a choice about... it is what it is.

Browse our website to learn more about Metroflor’s options for waterproof rigid core floors with attached underlayment, specifically Inception (SPC) and Genesis (WPC). At Metroflor you can be sure you’ll find a great solution for your home or business.