Reinforcing Soft and Crumbling Surfacing
Dealing With Cracking Grout and/or Surfacing!
( After reviewing each section below, see page bottom for general repair tips. )
Cracking due to movement:
Cracking through a grout joint and/or tile is most often caused by movement of the structure. This is seen most frequently at the juncture of wall and floor because the movement is along two planes. These surfaces move because of expansion and contraction throughout the day as temperatures fluctuate.
The best answer is to plan for this in construction. Allow gaps at edges that are hidden by molding or cabinetry. If that is not possible (as in the picture above), there are flexible caulkings that are made to be used on exposed perimeters and match the grout color. Check with your tile dealer for "colored caulk".
If an existing installation, here are options to consider:
In each of the cases discussed below, the answer is a petroleum solvent based acrylic sealer.
Slates and other materials that flake and powder from foot traffic:
Notice the cleft into the slate that is at risk to flake off under foot traffic. The following also applies to any materials that have soft areas prone to turning to loose particles.
Some materials have soft areas that go so far down that the sealer cannot get down far enough to strengthen at that level. It is difficult to know this, so all you can do is the best possible to achieve good penetration. It might be a good idea to use (or start with) a lower solids sealer even if a higher solids sealer would normally be your choice.
Grout or Mortar that is soft, cracking, crumbling
Any of the "solvent based - penetrating - acrylic" class sealers will penetrate into weak areas and make them stronger. A soft material is made stronger and its bond to the adjacent material is also made stronger. Erosion is prevented because the material is made "hard" by the sealer.
Cracks in grout/mortar
If the crack is small so that the sealer can bridge it, use the highest solids Aldon sealer within the "solvent based" - "penetrating" class that is appropriate for your surface type.
Sealers are not heavy bodied enough to bridge and fill cracks unless the cracks are quite small and the sealer is one of our "solvent based - penetating" types. Cracks over 1/32" wide should be patched with mortar or grout. For small cracks an "undsanded" grout mix available at tile stores will be able to enter and fill them where the particle size of a "sanded" grout might be too large.
Using caulking is less desirable for patching cracks as it might interfere with the sealer penetration and bond, and you will want to seal after patching. One of our "solvent based - penetrating" type sealers will enhance the bonding of new grout to old grout and to the tile edges.
Some ideas for repairing and hiding severe cracking, pits, holes, etc.:
Sometimes you are dealing with a situation where the cracking is so bad that it seems the only alternative is tearing it out. Since you have nothing to lose, consider the following concepts: