A warm roof is an assembly with insulation outside the supporting roof structure and below the waterproof covering. The term describes a construction arrangement rather than a particular product.
What does this mean on your roof?
This arrangement may be considered when renewing a flat roof. Required layers depend on the substrate, existing materials and selected system.
The label warm roof does not identify the insulation or covering included in a quotation, nor does it establish a particular thermal performance for the finished construction.
New insulation may raise the roof surface, bringing upstands, outlets and junctions into the scope of work. Ask for a layer description and an explanation of transitions to retained roof sections. Record which old layers will be removed as well. A description naming only the new external material does not establish that the complete construction has been assessed.
Frequently asked questions
Is every flat roof a warm roof?
No. Other arrangements exist; establish what is actually present.
Does warm roof guarantee a warm room?
It describes insulation position. Performance also depends on materials, junctions and the building.
Consulted 19 September 2026. Check requirements for your own address and selected system.