Cold Roof Insulation Between Joists

Where insulation depth is restricted by the flat roof construction it may be necessary to install the roof insulation between and below the joists to create a cold deck structure.

Cold roof insulation between joists. I intend to fill between my joists with foil backed insulation board 75mm with a thin layer of insulation on top of the joists. Refurbishing an existing timber joisted flat roof which has no insulation. Improving your home s energy efficiency rating. Cold deck roof 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.

It allows insulation to be added without having to replace the waterproofing on. There is only a small gap between this ceiling and a concrete roof cold roof felt covered. The insulation is below the deck but above the plasterboard. 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.

In this way the roof itself is kept cold. This is used for refurbishment e g. Introduction warm cold roofs this guidance offers guidance on the difference benefits between warm and cold roofs. You only need ventilation in a cold roof.

Ventilation is required for these roofs. Cold roofs by the way are not recommended for high humidity areas see the blog on how to insulate. In finished attic rooms with or without dormer insulate 2a between the studs of knee walls 2b between the studs and rafters of exterior walls and roof 2c and ceilings with cold spaces above. I ve built a timber frame to support a new plasterboard ceiling below the existing one.

Guidance advice on. This method of insulation can also be used to upgrade the thermal performance of an existing roof without affecting the waterproofing system. Poly to the underside of joists. 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.

A cold flat roof is one where the insulation is between or between and below the roof joists. No insulation is on top. Alternatively battens can be secured to the underside of the. Other benefits of roof insulation include.

Increasing your home s value. A cold roof is where all of the insulation is placed either between and under or completely under the joists or deck. Great videos thanks for sharing. As for insulating below the joists an insulating laminate insulation bonded to plasterboard such as celotex pl4000 or a separate rigid pir insulation board finished with a separate sheet of plasterboard can be securely fixed to the joists to provide an internal finish to the roof.

Easily the most frequently asked question to the celotex technical centre is with reference to hybrid flat roofs.