Insulating Hot Cold Flat Roof

For a 1 inch board equivalent of 6 r value.

Insulating hot cold flat roof. No ventilation is required for these types of roofs. On a warm flat roof the layer is installed underneath the insulation to stop moisture interacting with it through rising thermal pressure lower down in the building. Lots of traditional flat roofs are of the cold roof construction type. This means there is a vapour control layer in the ceiling and cross ventilation at the eaves or the top of the walls.

Many properties use this option as there are no additional costs for scaffolding or organising how to gain safe access to the roof exterior. With a warm roof the insulation is installed on top of the existing surface rather than in between the rafters. Warm deck or warm roof refers to a situation where the deck of the roof which is usually made of wood is below the. You can expect to pay about 55 100 sq ft.

This will enable the airflow to circulate freely. Flat concrete roofs are generally not ventilated since the ceiling internally is generally a plaster and skim coat directly to the underside of the cold concrete. Warm flat roof insulation. Cold roof a very bad idea.

This is then covered with a further weatherproofing layer. Cold flat roof insulation. Creating a void between the old ceiling and new is better but ideally you need to eventually consider insulating the top of the concrete roof with solid insulation and a better covering grp or epdm. 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.

To produce a hot roof rigid insulation is fitted outside above the weatherproofing. For cold flat roofs the vapour layer needs to be positioned underneath the insulation layer on top of the room below to create an effective barrier. Basically there are two options to choose from when insulating a flat roof. While expensive the best insulation is polyiso rigid foam.

Installing a warm roof can be extremely straight forward and simple to do. This may help with condensation but causes such a loss of heat that it has been banned in scotland. The insulation material is placed between the supporting joists leaving a gap of 50 60mm between the roof and insulation. There are three types of insulation solution if you have a flat roof.

We recommend having at least 20 r value worth of material for optimal energy efficiency. Warm roofs offer a superior thermal performance and therefore come with a higher cost.