Roof Ventilation Requirements Uk

The minimum requirements for cold roof ventilation are set out in bs 5250 control of condensation in buildings which takes into consideration span pitch and roof area.

Roof ventilation requirements uk.

The types of ventilation covered includes mechanical passive stack background and purge rapid. 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. Bs 5250 sets out the minimum requirements for roof space ventilation. Warm roof ventilation specification for a simple duo pitch roof bs 5250 specifies sufficient ventilation as being.

25mm at eaves on each slope and 5mm at ridge. Eaves soffits and fascias. Archived versions of approved document f are available at the national archives order printed copies. If ridge or eaves ventilation is not possible ventilation tiles can be used at high or low level to achieve the required airflow.

This page deals with roof ventilation and roof ventilation problems or the fitting of roof ventilation to existing cold roofs. A minimum 50mm free air path should be maintained between the top of the insulation and the underside of the roof decking. Swish ventilators for roof voids are covered by british board of agrément certificate no 91 2620. A cold roof is a traditional loft space as seen in the vast majority of uk homes and other parts of the world.

When used in accordance with the certificate swish ventilators will satisfy the following statutory requirements. 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. 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. 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. Ventilation openings shall have a least dimension of 1 16 inch 1 6 mm minimum and 1 4 inch 6 4 mm maximum.