When installing new flooring, you want to make sure it last for years to come. With all flooring, moisture from the subfloor underneath (concrete) can cause issues and can cause headaches months from now.
Why and how is there moisture in concrete slabs?
There is always water underneath the ground, while it might not be near the surface, it is there. Months or years from now the water table [link] might rise and the water will pass through concrete in water vapors with a capillary effect. Since concrete is porous, water vapors transmits from the ground through the concrete slab into your basement. Once the water vapors gather underneath your flooring, it will start to pool up and “soak” into your hardwood flooring. Once this happens, the flooring can buckle or warp and cause havoc.
With a 6-mil vapor barrier underneath your flooring, the water vapor will gather underneath the film and no longer reach your beautiful flooring. No more worrying if your floor will have issues. So why do all flooring manufacturer installation instructions mention installing a 6-mil vapor barrier underlayment underneath? The reason is quite simple: A 6-mil vapor barrier blocks all moisture from the subfloor from ever reaching your flooring.
Vapor barriers come in two types
6-mil vapor barrier roll
Our MoistureBlock is a 6 mil polyethylene film vapor barrier that is used during the installation process with floating laminate, luxury vinyl planks and engineered wood floors. No need to bother with large fold-out, low quality, off-spec, construction grade films, which can be bothersome and hard to use before the floor is installed.
Underlayment with 6-mil Vapor Barrier
Some underlayment come with a built-in vapor barrier that also provides extra benefits such as:
- Sound Absorption – Helps keep sound from reaching to other rooms
- Moisture Protection – MP Global Products QuietWalk DriWick technology allows moisture to wick away from underneath while protecting your floor
- Compression Resistance – Helps support the floor from high traffic areas and feel more comfort underfoot
- Thermal Insulation – Helps break the coldness from concrete flooring
It also never hurts to install both MoistureBlock and underlayment together as this offers total protection from moisture.
Best 6 mil Vapor Barrier Underlayment by Flooring Type
All Flooring – MoistureBlock
Laminate or Floating Floors (No Glue or Nail Down Installation) – QuietWalk Underlayment
Luxury Vinyl Flooring – QuietWalk Luxury Vinyl Underlayment
Hardwood Flooring – QuietWalk Plus Underlayment
How to Install Vapor Barrier on Concrete Floor Under Laminate Flooring
- Always read the flooring manufacturers recommendations and instructions before installing the underlayment.
- Before rolling out the underlayment, be sure to sweep, vacuum, and remove all debris on the substructure.
- Fill in any significant holes, gaps or breaks that may exist on the substructure.
- Roll out the Underlayment over the substructure surface.
- Leave roughly 2-3 inches along each side to overlap against the wall.
- Splice each roll of underlayment with a 3 mil tape, duct tape, or similar pressure-sensitive tape that meets/exceeds
the water vapor transmission ratings suggested by the flooring manufacturer.
- If installing MoistureBlock Film Underlayment with Self-Sealing film edge, simply connect the rolls by removing the
liner from the tape and adhere to the edge of the previous roll.
- Always be sure to connect the film rolls together with the adhesive tape evenly so that there are no gaps between
the adjoining rolls of film.
- Once completed, you can trim up the excess vapor barrier