Grout cracking

[Leatherface]

Best thing you can do is go and have a look.
If the grout is cracking in one specific small area then probably movement of some kind - lift the offending tiles, investigate, re-lay and grout.
If cracking in a few areas then problem with your grout, bedding or adhesive.

 

[felix]

I went to look at it tonight and there was cracking in the grout line around one tile. (Though not all the way around) There really was no movement in the tile. I lifted it and replaced it. I'll stop in on my way home tomorrow to grout it.

I still have no idea what caused it. If it had been movement I would have expected it to crack all the way round. Anyway hopefully that will be it. Thanks for the help guys

 

[Perry]

somtimes if its walked on before its dry it can break the bond it can be months before it starts moving usally in a doorway poss

 

[DHTiling]

There are several reasons for the cracking of grout joints including:-

1. Deflection within the substrate e.g. plywood which has not been sufficiently well supported.
2. Moisture expansion where boards are not water resistant and are therefore not dimensionally stable enough in changing moisture conditions.
3. Poor installation e.g. tiles not adequately bonded to the substrate resulting in loose tiles.
4. The use of a proprietary grout in tile joints which exceed the maximum width of the recommended joints by the grout manufacturer. i.e. drying shrinkage.
5. Joints which have not been completely filled with grout during installation, leaving voids where grout will not be adequately supported underneath the joint.

Use of BAL ADMIX GT1 in conjunction with a BAL Cement based grout will increase the flexural strength of the grout, increase adhesion strength to the tile edges and reduce water permeability through the grout joint. The admix can be used at a 2:1 water/admix dilution rate by volume up to a maximum dilution rate of 1:1 by volume with water.. Alternatively, use an epoxy resin based grout e.g. BAL EASYPOXY.
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