Warm Ventilated Roof

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.

Warm ventilated roof.

Our original design actually called for a hybrid with a vapor membrane beneath the rafters then 5 5 of roxul batts in the rafters below the sheathing and then roxul insulation boards atop the sheathing. The enclosed void of a warm pitched roof may not require to be ventilated but this is usually subject to the requirement to install a fully sealed air and vapour control layer avcl in conjunction with an air open roof covering. Ventilated cold roof or warm roof with insulation boards atop sheathing which serves to raise the dew point above the structural members of the roof. Because the warm roof method makes sure all of the roof structure is insulated it s a more energy efficient option over a cold roof.

Hot air exhaust vents located at the peak of the roof allow hot air to escape. A hot roof over a poorly vented attic translates into a very hot attic. Unventilated or poorly ventilated attics don t have an escape route for the heat that builds up. Warm roof build ups can be installed on most modern construction material types such as concrete timber and timber based sheets.

No ventilation is required for these types of roofs. 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. Warm roof ventilation specification. When the temperature outside rises the temperature on your roof can be nearly double.

Ventilation benefits a roof when it s hot outside as well. These roofs keep your home cooler during the hot summer months. However advice should be sought if using profiled steel decks with a. Because the sheathing is kept cooler roofing materials tend to have a longer life span.

Simply brush off any debris that is present secure insulation boards to the surface and then lay down your flat roof covering over the top. 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. A properly insulated ventilated roof can help to control or prevent the formation of ice dams. With the introduction of vapour permeable plastics underlays the need to create ventilated voids above inclined insulation and the requirement to ventilate cold roof lofts may be reduced.