The Warmup In-Screed Cable is an electric underfloor heating cable specifically designed for installation within concrete screed floors. It provides a flexible heating solution for new-build and major renovation projects, allowing the cable spacing to be adjusted to achieve 100W/m², 150W/m² or 200W/m² heat output. The system is particularly suited to rooms that are in regular use, as the surrounding screed provides thermal mass that allows heat to be stored and released gradually.
The Warmup In-Screed Cable is available in the following sizes. The heated area varies according to the cable spacing selected.
| Product Code | Cable Length | Power | Heated Area at 100W/m² | Heated Area at 150W/m² | Heated Area at 200W/m² |
|---|---|---|---|---|---|
| WIS180 | 9.0m | 180W | 1.8m² | 1.2m² | 0.9m² |
| WIS280 | 14.0m | 280W | 2.8m² | 1.9m² | 1.4m² |
| WIS390 | 19.5m | 390W | 3.9m² | 2.6m² | 2.0m² |
| WIS500 | 25.0m | 500W | 5.0m² | 3.3m² | 2.5m² |
| WIS650 | 32.5m | 650W | 6.5m² | 4.3m² | 3.3m² |
| WIS760 | 38.0m | 760W | 7.6m² | 5.1m² | 3.8m² |
| WIS1000 | 50.0m | 1000W | 10.0m² | 6.7m² | 5.0m² |
| WIS1200 | 60.0m | 1200W | 12.0m² | 8.0m² | 6.0m² |
| WIS1460 | 73.0m | 1460W | 14.6m² | 9.7m² | 7.3m² |
| WIS1550 | 77.5m | 1550W | 15.5m² | 10.3m² | 7.8m² |
| WIS1770 | 88.5m | 1770W | 17.7m² | 11.8m² | 8.9m² |
| WIS2070 | 103.5m | 2070W | 20.7m² | 13.8m² | 10.4m² |
| WIS2600 | 130.0m | 2600W | 26.0m² | 17.3m² | 13.0m² |
| WIS3140 | 157.0m | 3140W | 31.4m² | 20.9m² | 15.7m² |
| WIS3370 | 168.5m | 3370W | 33.7m² | 22.5m² | 16.9m² |
The available sizes and heated areas are taken from Warmup's current Inscreed Cable installation manual.
One of the main advantages of the Warmup In-Screed Cable is the ability to adjust the heat output according to the spacing used during installation.
This allows the heating system to be configured according to the requirements of the room and building. The appropriate spacing should be determined during system design and installation.
The Inscreed Cable is specifically designed to be embedded within a concrete screed. Warmup specifies a screed thickness of 50 to 100mm, making the system particularly suitable for new-build floors and projects where the floor construction is being rebuilt or substantially renovated.
The screed surrounding the heating cable provides thermal mass, resulting in slower heat-up and cool-down characteristics than some other electric underfloor heating systems. Warmup identifies this as useful in rooms that are in constant use, where stored heat can continue to be released after the system has been switched off.
The Warmup In-Screed Cable is installed within the concrete screed using the appropriate Warmup cable fixing system to maintain the required cable layout and spacing. Warmup's installation guidance specifies that the cable should be secured to the subfloor before the cementitious screed is poured.
The cable must not be shortened. The correct cable size must be selected for the heated area before installation. Warmup also recommends testing the heating system before, during and after installation to confirm that the cable has not been damaged.
Electrical connections must be completed by a qualified electrician, and the complete installation should follow the relevant Warmup installation instructions.
The Warmup In-Screed Cable is suitable for:
Once installed within the screed, Warmup states that the Inscreed Cable can be covered with a wide range of floor finishes.
The Warmup In-Screed Cable must not be cut or shortened. Select the correct product size based on the heated floor area and required heat output before installation.
The cable should be installed at the specified spacing and completely embedded within the required screed construction. Fixed furniture, sanitaryware and other areas where heating is not required should be excluded from the heated area when calculating the cable requirement.
Suitable floor insulation should be incorporated into the floor construction to help reduce downward heat loss and improve the overall performance of the heating system.
The Warmup In-Screed Cable provides a flexible electric underfloor heating solution for screeded floor constructions, with 15 cable sizes and three selectable heat outputs. Its installation within the screed makes it particularly suitable for new-build and substantial refurbishment projects where the floor construction allows for a 50 to 100mm screed layer.

Warmup In-Screed Cable
9m / 180W