Warm Flat Roof Soffit Detail

Warm roofs offer a superior thermal performance and therefore come with a higher cost.

Warm flat roof soffit detail.

The insulation is placed below the waterproof covering and is either mechanically fixed or bitumen bonded on to the top of the deck. With a warm roof the insulation is installed on top of the existing surface rather than in between the rafters. On a flat roof this could be air in at one ventilated facia soffit and air out via an opposite ventilated facia soffit. Warm roof ventilation specification.

No ventilation is required for these types of roofs. A warm flat roof is formed by placing a layer of insulation over the top of the roof structure. A warm deck roof is where the insulation is placed on top of the rafters joists and the roof covering is then placed over the insulation. Unvented flat roofs a technical discussion flat roofs have often been built with the insulation all on top of the vapor closed drainage plane as this avoids dew point condensation issues inboard of the roofing.

Steve from london flat roofingexplains how warm flat roof construction works in this excellent short video. The resultant action of which does not allow condensation to occur to any significant effect. The great thing about a warm roof is that if your existing roof surface is in good condition you don t need to do much to it. Introduction to flat roof details the roof is a key element of the building structure providing protection from the elements and has a vital role in reducing heat loss from the building.

For a simple duo pitch roof bs 5250 specifies sufficient ventilation as being. Warm roof or cold roof which would you choose if you have a choice. Roofs tend to be either pitched or flat and typically in residential construction timber is the most common material used. Inverted warm deck roof the insulation boards in an inverted warm deck are laid over the structural deck and the waterproof covering.

The abutment detail of a flat roof is vital in order to prevent moisture penetration. This ensures that the deck holds a warm temperature during the winter. Like a cold roof warm roof ventilation is required at high and low level to remove moisture laden air from the batten cavity and comply with approved document c and the british standards bs 5250. However in many situations the insulation may need to be primarily or entirely below the flat roof membrane and between the roof joists if so what are the best options.

Similar to the abutment of a lean to roof lead flashing is chased into the external block allowing it to overlap the lead upstand coming from the tiles.