Insulating A Ceiling Under A Flat Roof

It s what s called the cold roof principle.

Insulating a ceiling under a flat roof.

This may help with condensation but causes such a loss of heat that it has been banned in scotland. Insulation material is placed on top of the roof rather than in between the ceiling and the decking. The existing ceiling is sound but provides no insulation. Can a flat roof be insulated from inside from the ceiling of the area below.

Hi i have a flat roof extension built in the 1970s. Cold flat roof insulation. Not only can. This system was often used in the past but is not recommended nowadays.

Both these variants require different approaches to insulation which will be covered in this guide. Lots of traditional flat roofs are of the cold roof construction type. Due to a rewire i ve had to remove parts of the plasterboard ceiling and have found that there is no insulation in the roof i can see the roof deck and joists there is no vapour layer and the plasterboard is not foil backed. Bypasses are anywhere that there is a break in the insulation.

Insulating a roof from inside is technically feasible. Insulation is placed in between the joists underneath the roof surface above. This means there is a vapour control layer in the ceiling and cross ventilation at the eaves or the top of the walls. I want to insulate below a flat roof without removing the existing ceiling.

This could be a hole crack or other kind of unprotected space that the insulation does not cover such as around a light fixture. How to insulate a flat roof. However we lose r value where the taper is thinnest and need to insulate under the sheeting. I live in southern ontario canada where there are significant differentials of temperatures from summer to winter.

With a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same. I ve built a timber frame to support a new plasterboard ceiling below the existing one. With flat roof insulation a vapor barrier should sit between the joists and ceiling panels and the insulation on top. The quest for greater energy efficiency in buildings has led to increasing interest and need for insulation improvements in hvac equipment more airtight construction new materials and assemblies.

We are insulating a flat roof with tapered rigid insulation over a moisture barrier and then capped with modified bitumen. Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation.