HÖRSTAD Foil topped Chipboard Panel with return for 16mm pipe (150mm spacing) 1200mm x 600mm x 22mm. Grooved on one face as required to suit 16mm underfloor heating pipe with radius returns as standard. Typically installed directly onto floor joists (usually insulated in between), utilising standard chipboard screws and joint adhesive. An overlay board or suitable plywood should be applied prior to the application of any floor finishes. Suitable for new build or retrofit installations. Installed directly onto floor joists allowing for a lower floor build up. Foil top enhances thermal performance.