A 65mm screed will provide the best combination of heat storage and output. Thicker screeds may be used we recommend that 90mm is the maximum as heat transfer above this thickness is far less efficient.
Our system is suitable for pre mixed pumped screed, which may provide screeds as low as 45mm please discuss this with a professional screeding company.
A Warmis screed system will provide the highest heat output of all systems, furthermore, they are the cheapest to purchase, as in most cases the pipe loops are secured to foil faced insulation and then covered with a 65mm screed, this method effectively turns the building slab into the heat emitter.