Putting a moisture barrier underneath laminate flooring is essential if you are installing it over a concrete sub floor. Most manufacturers require it in order to maintain your warranties. Here are a few different kinds of moisture barriers that you could potentially use effectively.
Visqueen Barrier
A visqueen vapor barrier is one type of moisture barrier that you could use underneath laminate flooring. This type of moisture barrier comes in rolls that typically cover 100 square feet or more. You simply unroll them and tape them to the floor. This will help to keep any moisture that comes up from the concrete from getting into the laminate core. Since laminate still has wood in the core, it can swell when moisture gets into it. The visqueen will effectively prevent anything from coming through into the laminate.
2-in-1 Pad
Something else that you could potentially put under a laminate floor is a 2-in-1 pad. This type of material is actually a combination of a laminate pad and a moisture barrier. They put both of these items together in one easy roll. They typically come in the same size rolls as the visqueen vapor barrier and are installed the same way. This just makes it easier as you do not also have to install a pad.
Source: www.DoItYourself.com
