3 Things you Should Know About 3 in 1 Underlayment

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3 in 1 underlayment is typically a thin foam pad used under floating floors, usually created from either polyethylene or polypropylene.  It most often comes in rolls of 100 to 200 square feet and is rolled out onto the sub-floor before the hardwood, laminate, and vinyl tile flooring is laid down.

What Features Does 3 in 1 Underlayment Provide?

Underlayment is a key component of flooring installations, especially if you have a concrete sub-floor or you’re using an engineered hardwood floor.

Here are the three features of 3 in 1 underlayment:

  1. Has a moisture barrier (usually a plastic film barrier)
  2. Provides sound insulation.  (The higher the sound rating, the more sound it “muffles” or blocks.  Sound ratings are usually reflected in the STC and IIC rating factor)
  3. It is comprised of foam cushioning that makes up for minor imperfections in the sub-floor

3 in 1 Underlayment - Ambient® Bamboo Flooring3 in 1 Underlayment showing self-adhering strip on left and overlapping plastic on right

 

1. When Is 3 in 1 Underlayment Used?

This type of underlayment is most commonly used under floating wood floors, including laminate and vinyl tile products, and is typically not recommended for nail down installations.  It provides support as the flooring expands and shifts during temperature and humidity changes; however, 3 in 1 underlayment is more advanced and includes a vapor barrier, protecting the flooring from moisture.

2. Why is Underlayment Important?

This type of underlayment is most often used to provide a vapor barrier against sub-floor moisture and as a sound barrier.   It is used to muffle sounds between different home levels and those made from walking on the floor itself.  It provides support as the flooring expands and shifts during temperature and humidity changes; however, 3 in 1 underlayment is more advanced and includes a vapor barrier, protecting the flooring from moisture.

The best 3 in 1 underlayment with high STC/IIC sound ratings are frequently used in new condominium construction, where HOA boards often require minimum sound decibel requirements (usually 50 dba) are required to cut down on sound transmission between floors.

Think sound barriers aren’t important?  Watch the video below.

 

3. Do I NeedUnderlayment if I’m Gluing Down?

Not usually, but it depends.  Some installers will use a 3 in 1 underlayment in combination with a for added sound insulation.  However, typically the use of 3 in 1 pad precludes the use of adhesive.

There are a staggering number of differing underlayments on the market – choosing the right one is critical if your floors are to perform as they should, i.e., for as many years as possible.  If you’re going for sound reduction, always check the IIC and STC ratings to see how sound resistant the underlayment is.  The higher the STC/IIC rating, the more sound insulation you get (and the higher the price, usually).  There are underlayments as thin as 1mm and all the way up to 5mm or more in the case of rubber underlayments.

Also, bear in mind that given their differing qualities, every underlayment comes with its own manufacturer’s instructions – these must be followed to ensure the product does its job correctly.

Explore our underlayment range – search by thickness, square foot, or sound rating – you can also choose to search underlayments that have vapor barriers.

Last update of the article: 01/28/2021.

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