Sufficient cold roof ventilation.
Roof void ventilation building regulations.
Flat roof this usually consists of felting which has a slight fall to allow rain water to drain off.
Pitched roof spaces should have ventilation openings at eaves level to promote cross ventilation.
Airtrak is a proprietary range of ventilators designed specifically for the ventilation of roof voids.
Roof space ventilation introduction building regulation approved document c2 refers to bs 5250.
Ventilation can be achieved by using the rooflight for both rapid and background venting.
Where the void is open eaves to eaves air flow is effective along the longer sides of the building.
To enable compliance with the requirements of the building regulations to be demonstrated full details of the new roof will be needed including.
Brett martin recommend the use of high level ventilation in addition to eaves ventilation in all cases as it utilises the natural thermal uplift in a roof void.
To comply with approved document c and bs 5250 crossflow ventilation should be provided at both the eaves and or ridge level.
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 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.
Roofs with a pitch of 15 or more.
Isbn 978 1 85946 679 7 pdf 683kb this file may not be suitable for users of assistive technology.
Ventilation of the existing roof void s will have to be considered as air must still be allowed to flow from one to another.
Pitch roof this is where tiles or slates are used and a void is usually created underneath.
Ventilate the roof once water vapour has entered the roof space the usual and most practical way of removing it is by ventilation.
A roof void above an insulated ceiling.
The british standard code of practice for control of condensation in buildings as a means of compliance with a general requirement that adequate provision be made to prevent excessive condensation in a roof or roof void above an insulated ceiling.
This should ensure that effective through ventilation of the whole roof is achieved and assist in pulling moisture laden air out of the building and limiting condensation.
Open roof void building regulations state.
Airtrak assists specifiers builders and specialist contractors in helping them to meet the requirements of the building regulations in relation to the important issue of roof void ventilation and the control of condensation.
Additionally if the span is greater than 10m the overall ventilation area should be increased to at least 0 6 of the total roof area.
Both building regulations and nhbc require ventilation to be provided in roof spaces.
Ventilation 2010 edition incorporating 2010 and 2013 amendments ref.
