Roof Ventilation Building Regulations

Isbn 978 1 85946 679 7 pdf 683kb this file may not be suitable for users of assistive technology.

Roof ventilation building regulations.

Warm roofs must have a vcl bonded to the deck. Ventilation at the eaves. Cold roofs must have ventilation. Roofing resources during covid 19 for contractors for homeowners.

Ventilation is not required to a warm roof system which is where the insulation is placed above the joists or rafters. Duo pitch roofs greater than 200 pitch or greater than 10m span should have additional ventilation at the ridge to assist airflow through the roof void equivalent to at least a 3 mm wide continuous gap. The air gap dimensions shown on the drawings are the minimum widths required for clear continuous ventilation air paths at the eaves. To provide ventilation opening points can usually be provided on the following areas of a pitched roof.

Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of the roof framing members shall have cross ventilation for each separate space by ventilation openings protected against the entrance of rain and snow. Part h of the building regulations regarding drainage state that water should drain to one or two edges. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. Slating and tiling for pitched roofs and vertical cladding code of practice recommends that roof ventilation be provided in accordance with bs 5250.

Theinternational building code 2012 edition ibc 2012 requires enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof framing to have cross ventilation for each separate space. Otherwise ventilation is required and this is known as a cold roof system. The ventilation must be in compliance with section 1203 2 which states. When ventilating a roof the air should be able to enter at one end and travel through to the other end where it can exit.

The net free vent area nfva shall not be less than 1 150 of the area of the space being vented. Eaves soffits and fascias. Condensation encourages rot and mould growth. Waterproofing should extend up the adjacent walls at least 150mm from the roof surface.

Roof voids must be ventilated in order to stop warm air condensing on cold surfaces. Exterior openings into the attic space of any building intended for human occupancy shall be protected to prevent the entry of birds squirrels rodents snakes and other similar creatures. Openings for ventilation having a least dimension of not less than 1 16 inch 1 6 mm and not more than inch 6 4 mm shall be permitted. Roofs must be wind resistant and strong enough to walk on.