RetroTherm® FLO 12 Low Profile Underfloor Heating Castellated Tray (Self Adhesive) – 12mm pipe

The RetroTherm® FLO 12 castellated tray system from TUS offers a low profile alternative to conventional wet screed underfloor heating systems, where build-up heights must be minimised.

This low top, egg crate style tray holds a 12mm pipe and is suitable for screed levels of just 25-30mm. This makes the trays popular for renovation and retrofit projects, particularly where the subfloor is insulated.

Designed as an installer-friendly, durable solution, the tray is made from rigid recycled high impact polystyrene and features a thermoformed, perforated structure, pre-coated with a pressure-sensitive adhesive on the base for easy bonding to mineral substrates such as concrete or screed. This eliminates the need for extra adhesives or fasteners, ensuring a secure and permanent fix to the existing surface. A silicone release liner protects the adhesive prior to installation of the tray.

These low profile castellated trays simplify and speed up the installation process even more with their simple push fit design. The profile securely holds 12mm pipework in place at variable spacings of 50mm, 100mm, 150mm, or 200mm, with no additional clips or tools required. They are also able to accommodate both concentric and serpentine pipe layout designs. Installers can walk directly on the robust mats whilst pipe laying, and the built-in connections along the tray edges make aligning panels fast and accurate.

The tray perforations allow self-levelling screeds to bond directly through the mat to the underlying floor, creating a solid, integrated floor build-up. For optimal performance, the substrate should be level, clean, and thermally insulated. Ensure your primer is compatible and appropriate for the floor substrate.

From small domestic renovations to large-scale commercial refurbishments, this low-profile wet screed system option ensures you can install efficient, high-performance underfloor heating without compromising on build height or installation speed.

Please note this item is subject to a Minimum Order Quantity of 25 panels. For assistance with smaller orders, please contact our customer service team.

Need help planning your install or calculating materials? Call our team today on 01283 850040.

TECHNICAL INFORMATION:

• Panel size: 1220 x 820 x 15mm
• Panel coverage: 1m²
• Pipe size: 12mm
• Pipe spacings/centre options: 50, 100, 150, or 200mm
• Tray is compatible with both concentric and serpentine pipe layouts
• Panel substrate thickness: 1mm
• Panel material: Polystyrene (PS), thermoformed and perforate
• Compatible substrates: Cement concrete, anhydrite screeds, ceramic floors (with correct primer)
• Substrate preparation: Universal primer (or primer suitable for the substrate)
• Wet system – screed required
• Screed requirement: Ensure screed is appropriate for low profile system (25 – 30mm)
• Fixing method: Self-adhesive
• Suitable for renovation and retrofit applications