Building Regulations - Approved Document F1 - F2

Condensation in Roofs
F2. Adequate provision shall be made to prevent excessive condensation -
a) in a roof; or
b) in a roof void above an insulated ceiling

BRE Report - Thermal Insulation: avoiding risks

2.1 (c) Provide an air path to the roof space from the eaves ventilation opening equivalent to a 50mm continuous gap.

2.3 Condensation of Thermal Bridges
2.3 (a) Carry the loft insulation over the wall plate to link with the cavity insulation.

NHBC - Thermal Insulation 7.2 - S.14

• Cross Ventilation of the roof is provided
• Insulation does not block the ventilation path at eaves level
• Insulation is laid over the whole loft area, including the wall plate
• There are no gaps in the insulation