Roof turn out to be very essential part in house construction. No roof constructions are in it 100% tight, against wind blown rain or snow that can enter through the roof and down into the wooden construction. Wooden roof construction is expected to survive either heating or cooling the house.

Protecting from the weather changes makes roof should have more attention before rear. Roofing is a work that requires good experience and lots of patience. Roofing is considered as a difficult job compared to other home repair works. The roof with stand of rain, wind, sun and snow will show its durability.

In pitched roofing solution a roofing of high durability for the right roof construction is mandatory. Roof underlying is define which of two main roof contraction here are ventilated roof construction and unventilated roof construction.

Ventilated roof constructions, Ventilated roof is the traditional construction method used for roofs with a pitch angle of more than 15º. The ventilated roof can be warm roof or a cool. In warm roof thermal insulation follows the rafter line whereas in a cool roof thermal insulation is installed horizontally at sealing level. In any case a ventilation gap between a vapor tight roofing underlay and the insulation is needed. The ventilation gap will ensure a free and continuous ventilation to avoid harmful condensation built-up in the insulation material.

Unventilated roof constructions, the vapour roof underlay is also called the breathable roof. The type of underlay can be used for roof with a pitch angel more than 20º. The feature of this roof construction is that no ventilation gap needs to be built-in meaning no cold airs will insulation material down and thereby no insulation value is lost