Vapour Barrier under Laminated Floor

In the world of flooring the use of laminate floor is taking a fast pace these days. The look, the finish, and the resultant revolutionary remodeling of the room encourage its uses.

Though laminate flooring looks like proper wooden floors, there are no wood involved in its construction. It is made up of a wear layer, photo layer, fiber board core layer, and a stabilizing melamine layer.

It can be used over almost any floor in the house, with some exceptions. Laminate floor is not advisable in damp locations, such as bathrooms, sauna etc., and the rooms where dampness may occur in time. In order to keep this flooring from water and damp surfaces it is advisable to use vapour barrier under a laminated floor in case of using it over a concrete floor.

Problems of Using Laminates over Concrete Floor

As discussed earlier, laminate floor is vulnerable towards moisture or dampness. So it is always recommended not to use it where the area can be exposed to moisture. This happens with concrete floors. Concrete floors below ground are capable of storing a vast amount of water.

So it is always important to ensure that the laminate floor and concrete floor do never come in contact, otherwise the dampness from underneath soil can be transferred to the laminate floor and ultimately spoil the later one.

In terms of using a vapour barrier between laminate floor and underlying concrete one, to avoid the moisture and warping problem it is highly recommended that a layer of vapour barrier is used between the two floorings. Laminate floor can be installed over concrete flooring which has been installed at least 60 days prior to the new installation.

Polythene vapour barrier of 4 mil. or thicker is required to put under the laminate floor. In other alternative a 2 in 1 foam underlay with a vapour barrier built in can be used. There is probably very less differences between them. Remaining poly barriers can be used in another job involving another brand of laminate, but to avoid warranty related problems mixing materials from different manufacturers should be avoided.

Use of vapour barrier while installing laminate floor over radiant heat

Laminated floors can be used over radiant heat also, but it is not advisable to use it over electric heat floors. One outside thermostat should be used in order to minimize the effect of the rapid change of temperature on the flooring material. In this case also using polythene vapour barrier is advisable.

Before installation of laminate floor one must check whether the floor is moisture free, level, and clean. After that a 6 mil poly vapour barrier is laid around the room with extension of at least 5 cm up to the perimeter of the wall. Then the foam substance for flooring is applied over top of the vapor barrier by butting edges and sealing with tape.

Summing Up

The term vapor barrier is chosen because of the fact that it actually acts as a barrier between dampness and laminate flooring. The laminated floor actually floats over the foam based material underneath. This material is vulnerable to moisture.

Laminating material (be it tiles or planks) if exposed to moisture can cause severe damage to itself. Polythene based vapor barrier is used under laminating floors just to keep the moisture away. This actually creates a gap between the flooring and the moisture and never allows them to mix up, thus providing a long life to our laminated floors.