Is inscreed or undertile heating more effective?

An undertile electric underfloor heating system can be installed either directly below the tiles or in the screed layer. This means that it is ideal for both new builds and renovations. There is both matting systems and loose wire systems available for both in screed and direct undertile installations. These are the 150 watts per m2 and the 200 watts per m2. 150Watts per meter square system is commonly used directly in the tile glue and for larger areas, whilst the 200Watts per meter square system is used in a sand and cement screed bed.

The effectiveness depends entirely on how the system is used. There are some scenarios where 150W would be the most effective system to use, for example if it is only being used for a short period of time as this system heats up quickly. On the flip side being directly below the floor finish the floor also looses its heat faster. Whereas although the 200W inscreed system takes longer to heat up, the screed becomes a heat bank which will continue to release warmth into the room even after heating has been turned off.

Common floor buildups are:








For underfloor heating to be a primary heat source, 80% or more of the floor area needs to be heated. Therefore, in bathrooms we commonly recommend the 200W system for both in the screed and directly in the tile glue as 80% coverage is hard to achieve once fixtures (ie. toilets, vanities etc.) are taken into consideration. The main deciders between a 150W or a 200W system would be the floor buildup, the tilers preference and how the room will be used. Our product experts are ready on hand to recommend the best solution for your application or our system selector tool can be used at