Finished floor level advice

[carson321]

Hi, 

 

Looking for some advice on finished floor level. Currently having an extension built, will be having wet ufh routed in to the existing slab, which will then run over new celotex with screed up to existing slab level. 

 

I am going to have sliding doors installed with a flush threshold inside and out and need to know where my FFL will sit.

 

Planning on having 10mm porcelain throughout the whole area. In my head, my FFL will be about 20mm above current slab level, allowing for decoupling membrane, tile adhesive and tiles. Does this sound reasonable? I have my current slab level marked out next to the door opening ready to measure from, not sure if i should be thinking about an extra couple of mm to add a self levelling over the whole floor after the new screed is poured.

[Spinny]

A sketch of your planned floor makeup thicknesses and threshold design would help I think.

How big is the extension ?

 

We had a 7.6m extension and had our bifold company measure against FFL twice - once at survey, and then again at first fit visit - their laser measurements were 11mm different between the two visits (measuring over a 9m distance), even though nothing had moved. Laser levels are not guaranteed perfect and should be subject to some periodic calibration check. Over longer distances a water level is your friend - good to a couple of mm over any distance if used carefully.