Vapor barriers come in two types 6 mil vapor barrier roll.
Moisture barrier for concrete subfloor.
The concrete subfloor must be sufficiently strong to safely support the flooring furniture and people in the room.
The reason is quite simple.
Vapor barriers are a way to keep moisture from getting into the concrete.
Snap the chalk line over the top of the concrete or moisture barrier between the marks on opposite walls making a cross in the center of the room.
For optimal moisture control you will want to overlap the poly barrier by at least six inches.
You will lay the flooring lengthwise to this wall.
When rolling out the moisture barrier you want to go from wall to wall and cover the entire floor.
Compare the results against the manufacturer s specifications for moisture limits.
A vapor barrier is not the same as an underlayment.
A 6 mil vapor barrier blocks all moisture from the subfloor from ever reaching your flooring.
This video describes the process of installing a moisture barrier over a concrete subfloor.
With your concrete subfloor you will need either a standard foam underlayment with a moisture barrier film or a 2in1 underlayment with moisture barrier already installed.
The presenter is using 6 mil thick poly barrier.
Check the moisture level of the subflooring using a moisture meter.
This is why a vapor barrier under concrete is essential.
Usually buying the 2in1 is an easy and more economical option.
If you have a concrete floor that s in continuous contact with a source of moisture you re going to have problems.
How to install vapor barrier on concrete floor under laminate flooring.