I am installing ufh in my (tiny) house conversion. The total area is 22 square metres, and will be a tiled living / dining / kitchen area. Since I’m also laying the floor slab I have the option of placing a reinforced 100mm slab on top of the insulation (250mm eps) incorporating the ufh pipes instead of the conventional 100mm slab, insulation and 65mm screed method. Building control have OKed this.
I’ve investigated pumped screeds and ruled these out due to the expense on such a small area, so my question is, how much will the ufh performance be affected by being laid in a 100mm concrete slab versus a 65mm screed? Ufh manufacturers imply slower response times would be a problem, but I’m interested to hear from someone who’s actually done it – my builder seems to think it won’t be an issue, and the ease of one lot of concrete being laid rather than two is attractive. However I won’t have a secondary heat source to supplement the ufh so I want to be sure it’ll be affective and reasonably controllable.
If I go down the conventional slab and separate ufh in screed route, how long would I have to leave the slab to cure before laying insulation and screed on top?
Many thanks in advance!