Roof Ventilation Requirements Uk

Warm roof ventilation specification for a simple duo pitch roof bs 5250 specifies sufficient ventilation as being.

Roof ventilation requirements uk.

For example in the average house with a cold loft there should be a minimum of a 7mm continuous ventilation gap at eaves when using a vapour permeable underlay with a normal unsealed ceiling. Roofing ventilation online part of the drainage central group is here to provide quality products at competitive prices to its customers across the united kingdom. This page deals with roof ventilation and roof ventilation problems or the fitting of roof ventilation to existing cold roofs. 25mm at eaves on each slope and 5mm at ridge.

Bs 5250 sets out the minimum requirements for roof space ventilation. Slating and tiling for pitched roofs and vertical cladding code of practice recommends that roof ventilation be provided in accordance with bs 5250. To provide ventilation opening points can usually be provided on the following areas of a pitched roof. Our supplier ariel plastics is part of the brett martin group one of the world s leading polycarbonate sheet manufacturers and the uk s market leading rooflight manufacturer.

This specifically relates to cold flat roofs which require ventilation because they are more susceptible to high levels of condensation developing on the decks and external tiling or cladding. The wider the span the more free airflow is required in the roof space. A minimum 50mm free air path should be maintained between the top of the insulation and the underside of the roof decking. When used in accordance with the certificate swish ventilators will satisfy the following statutory requirements.

A cold roof is a traditional loft space as seen in the vast majority of uk homes and other parts of the world. Ventilation openings shall have a least dimension of 1 16 inch 1 6 mm minimum and 1 4 inch 6 4 mm maximum. Swish ventilators for roof voids are covered by british board of agrément certificate no 91 2620. To meet the requirements set out by the government for thermal insulation roof ventilation may be a requirement in order to achieve the desired certification for the property.

Eaves soffits and fascias. The types of ventilation covered includes mechanical passive stack background and purge rapid. Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof rafters shall have cross ventilation for each separate space by ventilating openings protected against the entrance of rain or snow.