Yes, XPS is one of the most recommended insulation materials for radiant floor heating (hydronic or electric). It is placed beneath the heating elements (tubes or mats) to direct the heat upward into the living space instead of being lost downward into the subfloor or ground. Its key benefits for this application are:
- High Compressive Strength: It can withstand the weight of the concrete slab or flooring system above without compressing, which would reduce insulation effectiveness.
- Moisture Resistance: Prevents moisture from the ground from degrading the insulation or affecting the system.
- Pre-Formed Channels: Many XPS boards for radiant floors come with pre-cut grooves or channels to hold the PEX tubing securely in place, speeding up installation.
- Reflective Foil Facing: Some products include a laminated reflective foil layer to further enhance heat reflection upward.
