Hardwood under vinyl tiles. Should I prime, to waterproof?

[Mike D]

I am about to lay vinyl tiles in my bathroom, and plan to cover the floorboards in hardboard first. Should I coat the hardboard in anything prior to laying the tiles?

I'm concerned that a water spillage would leak between the tiles and soak into the hardboard causing problems such as swelling or tiles coming unstuck or whatever. Is that a sensible concern?

Thanks,

Mike D

[Ian.Hamilton]

Hi Mike

I wouldn't use hardboard, if you are to stick tiles on to it because the harboard will easily become satuated with water no matter what you prime it with. It is likely to swell and lift your tiles well.

I haven't done the task my self but if I did I would be inclined to use thin Plywood and seal it with a waterproof sealant, not forgetting the edges and I would use a flexible sealant around the Plywood edges (to the wall) before placing the tiles. I would further seal the tile edges to the wall.

All this said hardboard base with a cusion flooring is a simplier solution but again requires sealing around the edges.

Good luck

Ian