Warm Flat Roof Insulation Between Joists

Insulation material is placed on top of the roof rather than in between the ceiling and the decking.

Warm flat roof insulation between joists. As i understand things the space between the joists is left as a void as insulation is above this so to avoid condensation issues. Whether you re looking to insulate at joist level for a cold roof where joist depth can be an issue or above the roof deck where overall roof height may need to be considered if a warm roof construction is desired. How to install insulation in a flat roof with timber deck insulated above the joists. Both these variants require different approaches to insulation which will be covered in this guide.

How to insulate a flat roof. The underside of the rafters in this case will need to be finished with a suitable vapour control layer vcl and plasterboard to provide a suitable internal finish to the roof. Hopefully that helps and there won t be any arguments. Other benefits of roof insulation include.

Good question theoretically when building a warm roof the vaper control layer goes on the warm side of the insulation. This type of detail gets accepted on garage conversions and the like but they are conversions not new build where there is little scope to achieve a proper warm roof as the existing roof finish is being retained. Warm deck insulation 1. Alternatively battens can be secured to the underside of the joists and gmw fitted between these in much the same way as between the main roof joists.

Insulation is placed in between the joists underneath the roof surface above. A cold roof would usually have a 50mm ventilated cavity between the roof deck and the insulation between the joists. If its in between and no vents its a hybrid and may or may not be accepted by building control. Improving your home s energy efficiency rating.

I have a flat roof warm construction so all the insulation is on top of joists rafters never know which term to use for flat roofs. Flat roof insulation. A warm deck roof is where the insulation is placed on top of the rafters joists and the roof covering is then placed over the insulation. The space under the flat roof is divided into a 2 rooms by a timber stud wall.

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. No ventilation is required for these types of roofs. 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. Its only a warm roof if there is insulation above the joists.

Set the quinn therm qrfr ply insulation boards onto a wide 30mm bead of vapour resistant sealant applied to the upper surface of all the joists and cross noggins.