Flat Warm Roof Build Up

Warm cold and inverted.

Flat warm roof build up.

Others would treat even steeper pitches as flat roofs. There are three recognised designs of flat roof construction. This could mean flat roofs may not raise the same red flags they used to. A great home requires a great roof.

Warm flat roof fully packed with insulation to prevent any condensation build up. In these days of energy preservation a roof can also contribute to preventing warmth being lost from a building. Flat roofs have a reputation of failing early but improvements in strength flexibility ageing and weather resistance mean that if built with care using the correct materials today s high performance felts can have a life span of up to 20 years. Where insulation above the roof void allows the air underneath to stay warm avoiding condensation but also allows for an air flow should one be deemed to be required through the joists.

In a warm roof the thermal insulation is immediately below the membrane finish the structural deck any voids and the ceiling are at a temperature close to that of the building s interior condensation control is achieved by using a vapour control layer vcl on the warm side of the insulation. Flat roof constructions are generally classed as either cold or warm. When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off. The major difference between the warm flat roof and the cold flat roof has to do with the air flow between the roofing timbers known as joists that help to hold up the roof.

The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal however some in the industry would consider up to 15 o as their definition of a flat roof. Warm roof build ups can be installed on most modern construction material types such as concrete timber and timber based sheets. Flat roofs are hard to replace. In the warm flat roof construction there is insulation packed into every possible space where air can flow.

A great and strong roof ensures no trouble during rain and strong winds for the residents. A good roof requires maintenance like any. But now flat roofs often are constructed with fewer layers because of improved waterproofing technology. They can be built up from profiled metal decks as the insulation selected would provide enough rigidity to span the open sections of such decks.

In a warm roof construction the principal thermal insulation layer is located above the structural decking resulting in the structural deck and support structure being at a temperature close to that of the interior of the building.