Water Absorbency of Ceramic tiles

[DouggieB]

Hi All,
A while back a short course on tiling and have done a couple of smaller projects in the house. My brother in law has asked if I would be able to help him with his bathroom. It's not too big so it should be fine, but I need a little advice on tile suitability. He's looking at ceramic as he hasn't got the budget for porcelain, but has been reading too much online and is now confused. His main concern is waterproofing/absorbency.

Can anyone shed any light on what would be a suitable/recommended level of water absorbency for wall tiles in a shower area? Any links to resources I can send him to would be great.

Cheers,
Doug

 

[rieveleyceramics]

You will find the vast majority of wall tiles have porous bodies. They are designed that way so they will grip the adhesive layer when fixing. It is the glazed surface that is impermeable and the grout that stops water getting through to the substrate. Silicon is also used by many along corners and where tiles meet edges of sinks, baths, floors, anywhere wher water may accumulate. On grouted vertical surfaces there isn't a problem.
In the past a cement based adhesive would have been used until the introduction of PVA based adhesives. It is these PVA adhesives that are susceptible to softening and breakdown when subject to prolonged moisture.
So for walls a porous bodied tile is perfectly satisfactory.
On floors an impervious tile body is more suitable, especially in areas which may continually be submerged or have prolonged periods of wetness and standing water. It is also important to have a none flexible subfloor to put tiles on. Otherwise both tile and grout are likely to fail and then water will easily seep into the substrate.