Cold Roof Insulation Between Joists

Refurbishing an existing timber joisted flat roof which has no insulation.

Cold roof insulation between 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. How to install insulation in a flat roof with timber deck insulated between and below joist. To form a vapour control layer seal the joists between the boards. 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.

Insulation between the joists keeps warmth in your living space below and creates a cold loft while insulation in the rafters allows you to keep warmth in the roof space as well. Install quinn term ql kraft insulation boards below the joists using suitable mechanical fixings. Other benefits of roof insulation include. Ventilation is required for these roofs.

It is preferred to have the bulk of the insulation between the joists to reduce any risk of condensation. The insulation is below the deck but above the plasterboard. Colde deck insulation 1. Poly to the underside of joists.

Cold roof a cold flat roof is one where the insulation is between or between and below the roof joists. The majority of domestic cold flat roofs use insulation between and under the joists. A cold deck flat roof will typically require insulation to be installed between the roof joists to comply with building regulation requirements.