No products in the cart.
Expert Answers
Why are my porcelain tiles cracking in 6 yr old home?
QUESTION
Porcelain Tile Cracking - Hello. I live in a 6 year old, one level home on concrete slab. My porcelin tiles are cracked inside the front entranceway and also inside the master bathroom for a total of about 10 feet. Two tiles were replaced in the master bathroom abput 2 or 3 years ago and now 4 of them are cracked across! Help!ANSWER
ANSWER - Porcelain tile, which is a type of ceramic tile, can crack for a variety of reasons, although if installed correctly it should never crack.Considering your tiles are installed on a concrete slab on grade then I will assume there can't be too much deflection in the floor as there could be if it were installed over a wood subfloor.
Concrete slabs can crack. If it is a shrinkage crack or non-structural control joint (only moves horizontally) they should be covered with a tile crack isolation membrane that either covers the whole floor or covers the crack at least the width of threes the width of the tile. For example a 12x12 inch tile would have a 36 inch wide crack isolation membrane centered over the crack. If the crack is a structural crack (has vertical displacement and moves vertically) then it has to be evaluated by a structural engineer and repaired with dowels and epoxy per the engineer's requirements. A crack isolation membrane will not work over structural cracks.
If the tile doesn't have full thin-set adhesive contact under all of the corners and edges of the tile and overall at least 80% contact for interior residential dry applications, and 95% in all other cases, then the voids under the tile can lead to cracking in the tile. If there are voids under the tile and that portion of the tile is subjected to a live load force then that portion of the tile is susceptible to cracking.
If a tile has lost its bond to its substrate it too can be susceptible to cracking from walking over it.
Tile installations that don't have movement joints can lead to cracking in the tile. All tile installations are suppose to have movement joints, also known as expansion joints, installed at its perimeters and transitions, and throughout the field of tile every 20 to 25 feet interior and every 8 to 12 feet exterior or in interior areas subject to direct light or moisture. Lack of movement joints are normally a compounding factor among other deficiencies that cause failures.
You can remove the cracked tiles and properly prepare the substrate and apply a crack isolation membrane over it if there is a shrinkage crack or control joint. Make sure you use a polymer modified thin-set mortar to fully bond the tile to the membrane or slab. Make sure the perimeters of the tile installation have movement joints filled with an ASTM C920 sealant. Good luck.
4 thoughts on “Why are my porcelain tiles cracking in 6 yr old home?”
Leave a Reply
Does ASTM C920 sealant come in colors to match the grout color?
Most manufacturer’s of tile and stone grouts have coordinating colors in the ASTM C920 silicone sealants with the same color name. Of course they are not a perfect match because they are different materials. Sealants normally has a slight sheen to it.
Manufacturers of ASTM C920 polyurethane and silicone sealants also provide a range of colors to choose from.
I have 7 tiles with hairline cracks— my house is 2 1/2 years old. My builder says it’s from ground settling-.
Some builders and tile installers like to blame tile cracking on the ground settling, which is not likely. If the ground settled then the builder didn’t properly prepare the soil prior to building the house.
If there were a settling problem the crack in the tile would have what we all lippage. That is where one side of the crack is higher than the other side of the crack.
It is more likely that either the concrete slab cracked and eventually telegraphed up through the tile or the installer had voids under the tile and that portion of the tile was subjected to a load that resulted in the crack, or the installer didn’t install movement joints at the perimeters of the tile installation or within the field of tile every 25 feet that resulted in cracking.
The only way to know for sure what caused the cracking and to determine how best to remediate it, is to remove some of the cracked pieces and look for the evidence of what caused it.