Cold Roof Insulation Between Joists

The insulation is below the deck but above the plasterboard.

Cold roof insulation between joists.

Colde deck insulation 1. This is used for refurbishment e g. To form a vapour control layer seal the joists between the boards. A cold deck roof is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof.

A cold deck flat roof will typically require insulation to be installed between the roof joists to comply with building regulation requirements. Install quinn term ql kraft insulation boards below the joists using suitable mechanical fixings. It is preferred to have the bulk of the insulation between the joists to reduce any risk of condensation. Ventilation is required for these roofs.

Other benefits of roof insulation include. Refurbishing an existing timber joisted flat roof which has no insulation. This quetion is to do with warm roofs and cold roofs presumably the 50mm of insulation on the underside of joists would act as the vapour barrier if taped sealed correctly or if insulation between joists a vapour barrier i e. The majority of domestic cold flat roofs use insulation between and under the joists.

Poly to the underside of joists. The rule of thumb for foil faced boards like thermapitch tp10 or kooltherm k7 in this scenario is that you can have no more insulation under the joists than you have between the joists. Unless the joists are exceptionally deep there is also likely to be a requirement to install insulation to the underside of the joists as the upper 50mm of joist space is usually required to be left clear for ventilation purposes.