andy tiler

hi grumps chipboard will be fine if there are enough joists to keep it rigid once
screwed down.over board the chipboard with warmup insulation boards a bit
expensive at first but cheaper in the long run.the floor will heat up quicker with these
never use 2part flexi adhesive with underfloor htg because most 2part flexi adhesives are rubberised not recomended with underfloor htg use a single part flexi. u only need a 200wpm if its your sole source of htg
hope this helps