The Building Process

The first few pictures show preparations of a block and beam floor prior to laying underfloor heating pipes. This floor will eventually receive a 2" screed. The black DPM around the perimeter of the room was bedded into the blockwork and, by fixing to the rest of the DPM (coloured olive green) with double sided tape, provides the barrier to Radon as required for "basic" Radon measures. An alternate method is to bed DPM into the blockwork and paint the floor with a bitumen paint.


	Cavity insulation sheets have been laid onto the radon barrier, providing the insulation.
Clear polythene sheetng is now laid onto the insulation - this will prevent the screed from penetrating between the insulation sheets, getting underneath and raising the sheets up
	The photo on the left shows the floor just after the screed has been pumped - some water comes to the surface.
In another build, the next pictures show the preparations for containing central heating pipes within wooden trunking and cables within metal conduit, onto which a screed will be poured. Here, the slab has been laid on top of the polystyrene insulation sheets so the screed goes directly onto the slab.