When is a crack…not just a crack…
Friday, April 11th, 2008Hello to all,
I want to talk to you about cracks in tiled floors.
If you have a older house, perhaps, and your tiled bathroom floor has a long, virtually straight, crack that reaches from wall to wall, this may indicate a structural problem. If the crack goes through the center of the tiles, not just the grout lines, and the tiles along the crack are still firmly imbedded, this more than likely indicates that one (or more) of your floor joists have been damaged from water, insects, or may have just sagged over time. This kind of damage can cause your tile floor to crack along the plane of the most affected joist. A true repair may involve demolition of the bathroom and replacement of the joists and sub-floor.
In a newer house, a straight line crack on your bathroom floor usually indicates improper tile installation. If the crack affects only the grout lines, turns 90 degrees, or several tiles and/or the grout is loose surrounding the crack, this may indicate that your tile was set directly onto the plywood sub-floor, rather than a proper tile substrate (or base layer). Wood expands and contracts with the amount of moisture in the air. If tile is set on plywood, problems tend to show up at the joints where expansion is greatest. To properly set tile, a cementious backer board on thin-set (as a cushion) should go over the plywood sub-floor, with staggered joints to avoid cracking. The good news is that your joists and sub-floor should not need replacing. The bad news is that all that tile you paid to have installed just a few years ago must be ripped up and replaced.
Avoiding problems with tile is as simple as knowing a few rules, and insisting on the proper tile installation. Always remember that tile is supposed to be set with a cementious product (such as thin set), on a cementious backer-board (such as Durock), for all floors and any wet applications like showers and tub surrounds. Other materials like mastic on drywall tile installations only work well for tile installations on walls in non-wet areas such as kitchen backsplashes and wainscot (tile to a four foot height on bathroom walls, not including shower and/or tub surrounds).
If there is a crack in your tile floor, ask yourself when the tile was installed. Then try to get a look under the floor to see if there is any evidence of joist damage such as mold, discoloration, sagging, rot, or insect holes. Contact a professional as soon as possible if you see any of these signs. Improper installation is not dangerous, but should be addressed before water damage can occur.
Rebecca


