Pitched Roof Eaves Ventilation

When using vapour permeable roof underlays in a pitched cold roof is it necessary to provide ventilation trays at the eaves.

Pitched roof eaves ventilation. Set top of fascia board at correct level and fit ventilator in accordance with manufacturers recommendations. If the attic space is going to be conditioned either for living or mechanical purposes or if a home design calls for a vaulted ceiling provision r806 3 in the international residential code calls for the roof deck above the space to be vented continuously from the eave to the ridge. The requirements will be met by the ventilation of those roofs where the moisture from the building can pass through the insulation. If the roof covering or roof membrane is a material of high moisture resistance or impermeable then the building regulations require a 50mm wide ventilation gap.

To provide ventilation opening points can usually be provided on the following areas of a pitched roof. The ventilation requirements of a pitched roof depends on the type of roof membrane used under the tiles or slates and battens to keep moisture or rainwater coming in from outside. Eaves with over fascia ventilation. Vent the roof deck.

The air gap dimensions shown on the drawings are the minimum widths required for clear continuous ventilation air paths at the eaves. Eaves courses of tiles should be at same pitch as general tiling. Eaves ventilation is a simple and effective way of providing the necessary air movement within a cold roof. Duo pitch roofs greater than 20 0 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.

If a sprocketted or bell cast detail is used then eaves courses should beno lower than the minimum recommended roof pitch. The roof is covered with high water vapour resistant type hr underlay and the pitch exceeds 35 or the span exceeds 10m this is in addition to eaves ventilation. It is most effective when used in conjunction with high level roof ventilation provided by corovent slate tile and ridge vents. A roof void above an insulated ceiling.

Eaves soffits and fascias. Types 1f 5u felts is used eaves ventilation should be provided on opposite sides of the roof to permit cross. Pitched roof spaces should have ventilation openings at eaves level to promote cross ventilation. Nhbc standards clause 7 2 14 requires that where a vapour permeable underlay vpu is used in a cold pitched roof the roof should be ventilated at ridge or high level.

We stock a wide range of pitched roof vents and roof ventilation products from leading brands such as ubbink marley eternit redland. Roofs with a pitch of 15 or more. Where high water vapour resistant type hr underlay e g.