The Church has timber floor, roof and furniture.


The pine wood block flooring is around 100 years old, and although this type of floor is not usually
suitable for underfloor heating, low temperature Lithotherm has been selected to overcome
problem of wood blocks warping as moisture content changes.

A 3m x 3m test area is used to check how the floor reacts to the underfloor heating. 
The existing tiles are lifted, then a self-leveling screed put down (24hrs to dry),
followed by 100mm floor insulation, and the Lithotherm tiles.


A 120mm gap is left at the ends for pipe loops.
In test we poured some screed into gap at edges before clipping in pipes, but leaving
30mm depth free from surface of tile (2 x 14mm where pipes cross-over).
It is generally advisable to leave all edge filling-in until after pipes are laid.

Pipes are then clipped into the Lithotherm tiles at 90mm centres.


Pipe is laid with flow and return next to each other - first the flow is laid, every 4 tile grooves, 
then at the end this is turned back and the return is run again every 4 grooves,
between the flow pipes. 



With tiles and pipes installed, the test area is ready for the gaps at the ends to be filled with 
more standard screed to bring the level flush with the tiles, before a final skim of 
self leveling screed is to be applied.

A final skim of latex self leveling screed is applied.
ONLY EVER APPLY SELF LEVELING SCREED IN ONE THIN LAYER !

Once the top screed has dried, newspapers were laid to prevent the bitchumin on the backs of
the lifted tiles affecting the screed surface, and then the tiles were laid loosely on top.

The floor is connected to a thermal store fitted with an electric element. 
A pump and thermostatic mixing valve on the store regulate the 
temperature of the water pumped around the test area.

The floor is left to run at 30°C for at least 3 days to allow tiles to acclimatise.

Temperature measurement of surface.