Use and Care Guide

4. Is it necessary to install a plastic moisture barrier film underneath a wood fiber
underlayment?
A polyethylene film (or "plastic film") usually acts as a vapor barrier to various moisture vapors.
When placed under the underlayment, it prevents condensation of water vapor on the lower
surface of the underlayment and/or the finished floors. By doing so, it protects from mold and
mildew formation underneath the floors and extends the service life and comfort of the floors.
An excellent choice to utilize as such a barrier is a 2mm plastic film (available in the US as a 6
MIL film).
During installation the plastic film strips should be laid on a dry and cleaned subfloor. The strips
should overlap about 15 – 20 cm (4"-8") and should be secured with a water resistant tape. On
the perimeter of the room the plastic should be brought up onto the walls up to the heights of
the intended baseboards.
There is NO NEED for a plastic vapor barrier in the following cases:
• On dry subfloors - where there is no direct source of moisture or water vapor and in
places such as slabs in between floors.
• On wooden floors and subfloors.
• On top of existing finished floors that were time-tested to be moisture free.
The plastic barrier should be used in the following cases:
• When the underlayment is installed on a freshly finished concrete subfloor with
residual moisture.
• In basements.
• On the first floors of structures in regions with high groundwater levels.
In damp spaces, It is generally NOT advised to install finished floors (and their components) that
are affected by moisture.
The plastic moisture barrier film is only an additional layer in the flooring structure.
It cannot replace the functions meant for the underlayment, that include: - Extending the
lifespan of the floors.
- Create acoustic comfort in the room.
- Level and smooth the subfloor.
- Eliminate unpleasant effects (such as squeaking noises) when walking.
5. Why do even thin wood fiberboards exhibit thermal insulating properties?
The remarkable thermal insulating properties of wood fiberboards are mainly due to the fact
that the fibers are bound with a natural glue, known as “lignin”, and many pores are formed.
The air that fills these pores acts as a thermal insulator. Moreover, the wood fibers themselves
have a porous structure which both enhances the “thermal insulating” properties of the boards
and creates and regulates a comfortable humidity level in the room.
Dozens of technologies are involved to artificially increase the porosity of materials and give
them thermal-insulating properties. The porosity index of the original natural wood is