Cold Roof Insulation Between Joists

Cold roof a cold flat roof is one where the insulation is between or between and below the roof joists.

Cold roof insulation between joists.

Refurbishing an existing timber joisted flat roof which has no insulation. A cold deck flat roof will typically require insulation to be installed between the roof joists to comply with building regulation requirements. 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. To form a vapour control layer seal the joists between the boards.

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. How to install insulation in a flat roof with timber deck insulated between and below joist. 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. 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.

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. This is used for refurbishment e g. Other benefits of roof insulation include.