Room in Roof Insulation
URSA Timber Frame Roll and Timber Frame Slab are suitable for use at rafter level for habitable or room in roof construction (warm roof space).
URSA TF Roll 35/Slab 35 - thermal conductivity 0.035 W/mK.
URSA HOMETEC Roll 35 - thermal conductivity 0.035 W/mK.
URSA TF Roll 32/TF Slab 32 - thermal conductivity 0.032 W/mK.
URSA HOMETEC Roll 32 - thermal conductivity 0.032 W/mK.
To minimise the condensation risk a vapour control layer is required when insulating between the rafters, this can either be a polythene sheet (minimum 500g) or a foil-backed plasterboard. The use of the vapour control layer also creates an air barrier that helps to improve the air tightness of the building and so limit air infiltration. The type of roofing underlay should be carefully considered. Breathable membranes (Type LR) may not require roof space ventilation provided they are covered by BBA certification. More traditional bitumen or polythene based membranes (Type HR) require provision for eaves to ridge ventilation.
The plasterboard ceiling should be sealed at the junction with walls with plaster, adhesive or flexible sealant and around service penetratations using a flexible sealant.
Recessed lighting should be in a sufficienctly large enclosure to ensure continuity of the insulation whilst still allowing heat to dissipate from the lamp. The fixture should be sealed to maintain a vapour tight ceiling and prevent unwanted air leakage.
With increasing levels of insulation it is vitally important to ensure continuity of the insulation around openings and at the junction of elements. Follow the guidelines in the Accredited Construction Details, Accredited Construction Details (Scotland), The Concrete Block Association and Constructive Details (for aircrete blocks).