If you have some sandstone tile fittings, either in your kitchen or bathroom, then after a while you may notice that it starts to look broken. Parts of the sandstone tile may fall off completely, and the stone itself will look weathered and badly damaged. This can be a serious concern, as broken sandstone tiles make a room look old and neglected, and they can effect the rest of the wall. In order to fix this unattractive appearance, you will need to make sure that you know the reason for the damage, and then use the best methods of repairing that particular tile.
Step 1 - Locating the Problem
If you have had a builder come in to look at your sandstone tiles, then you may still be unsure what the problem is. He might tell you that your sandstone tile is spalling, or scaling. Spalling is a term used to describe the flaking or falling away of the sandstone tile surface. Spalling is also used to describe one condition, then damage is caused by water being frozen inside the stone, and expanding. This can damage the surface of the stone. Scaling is used to describe delamination, where the exterior surface of the stone separates from the rest, and falls away, although the effect is the same as contour scaling, where small pieces of limestone fall off from the main piece.
Step 2 - Solving Spalling
Spalling can be solved by knowing the full extent of the problem. Tap some of the sandstone with the flat surface of a chisel. If it flakes off, then you need to locate the main water damage problem. Try following the flow of water to the nearest drain or gutter. If you can locate a leak, then seal this off first. You should then be able to stop the damage to the limestone by adding a mortar facing. This is done by applying cement mortar to the front of your sandstone tile. Use a trowel to get that into the right position, and then leave to dry overnight. Make sure that you cover all of the spalling sandstone, otherwise the mortar could just flake off. When the mortar has dried, apply a sealant over the surface.
Step 3 - Solving Scaling
Scaling of any kind, whether it is delamination or contour scaling, involves removing the part of the sandstone which has been affected. Start by using a hammer and chisel to take off the flaking areas, and ensure that there are no loose layers left on the stone. You should then sand it down until it is flat with the surfaces around it. Once this has been done, use a paintbrush to apply a layer of sealant over the sanded tiles. This will provide the sandstone with waterproofing, helping to avoid further troubles with flaking and spalling.