Can loft boards be used in a bathroom to replace floor boards?

Chipboard flooring is the norm these days.They should be green and moisture resistant though,not the rubbish that gets sold as loft panels.

As mentioned in the previous reply, chipboard is extensively used these days as it is stable ( no warping or twisting). The suggestion that it needs to be moisture resistant is as an insurance against the sometimes wet conditions in a bathrooms, though a properly fitted floor covering should guard against this. I would make sure that the chipboard is of the same thickness ( 18mm. - 22mm.) as the original flooring, and all joints are cut so as to be fully supported by the floor joists.

yes they can be used, no problem, although personally I hate them as they are nigh on impossible to lift without damaging. In my mind, if a floor is made up of floorboards then replace like for like. same goes for chipboard. You have to remember that wood expands and contracts with heat.If you replace half a floor with different flooring it will react differently to the rest and could cause problems if tiling onto them.

I personally would not recommend using chip board regardless of being treated (not on the floor anyway) this can be used inside a shower cubicle ready to be tiled over, however on a bathroom floor i would recommend using a ply at least 10mm.

yes he can replace the chipboard with like for like, but if they are tiling the floor they will have to use 12-18mm ply or backer board.