Roof voids must be ventilated in order to stop warm air condensing on cold surfaces.
Roof ventilation requirements scotland.
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The requirements will be met by the ventilation of those roofs where the moisture from the building can pass through the insulation.
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.
Roofs with a pitch of 15 or more.
The air gap dimensions shown on the drawings are the minimum widths required for clear continuous ventilation air paths at the eaves.
Enter square footage calculate or enter the square footage of the attic or area to be vented.
A roof void above an insulated ceiling.
We publish technical handbooks which explain how to achieve the requirements set out in the building scotland regulations 2004.
Section r806 roof ventilation r806 1 ventilation required 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.
Technical handbooks for use from 1 october 2019.
Refer to guidance to standard 3 17 and oftec technical book 3 where an extract fan is fitted in a building containing an open flued combustion appliance.
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.
The wider the span the more free airflow is required in the roof space.
Building regulations contain the technical requirements to protect the public interest.
Condensation encourages rot and mould growth.
A new standard bs 8612 was released in february 2018 and sets out minimum performance requirements for dry fixed roofing systems in regards to fixing wind load resistance durability and ventilation according to bs 5250.
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.
We regularly consult with industry to review our guidance.
This guidance page gives you a broad view of the requirements for using the roof space in dwellings and if more detailed information is required it is necessary to refer to the technical handbook and the building standards scotland regulations.
It applies to both new build and refurbished roofs.
The overall provision of trickle ventilation in a dwelling may be provided at an average of 11 000 mm2 per room with a minimum of 11 000 mm2 for each apartment.
