Will bathroom tiles adhere OK to foil-faced insulation board? I'm renovating a small bathroom. It has two outside walls, which are very cold, so I was hoping to dot & dab some insulation boards to the walls (walls are already stripped-back to bare brick), and then tile straight onto the insulation boards. I've got some spare 22mm "Kingspan" type board, which should be ideal, however it is foil-faced on both sides, so I'm not sure how well the tiles will stick to it. I was was thinking of painting on a slurry of adhesive first if necessary. Is this likely to be succesful? Thanks.