First floor underfloor heating.
We did this the hard way as it's supposed to be done from above.
As the ceilings were down anyway we fitted the heating from below, i don't recommend this but it saved cutting up the floor above.
We run the PEX up and down the joists then folded the edged of the aluminium spreader plates downward so they would fit between the joists and give us something to nail to the joists.
The spreader plates were pushed up from below so they are in contact with the underside of the floor and nailed to the joists.
40mm PIR was then pushed up against the spreader plates and held up with strips of wood screwed to the joists.
