JG Underfloor Overfit Board is a low-profile underfloor heating (UFH) pipe fixing system designed for existing floor structures. Ideal for retrofit projects, the pipe fixing system provides low height build up and is suitable for ground and first floor level applications. 15mm pipe is easily installed into a grooved foil-faced panel over an existing subfloor. Maximum pipe circuit length is 100m with a recommended flow temperature of 50-60ºC. Existing floor pipe fixing system Lightweight insulated panel with compressive strength Grooved foil-faced panel with 200mm centres Low height build up Medium to low heat output and response (approx.