Instead of a crack transferring from the concrete to the tile the crack isolation membrane absorbs the crack energy and spreads it over a large area preventing telegraphing through the tile.
Tile on concrete slab with cracks.
So random cracking might be a better approach for tile.
How to lay tile over cracked concrete cleaning the concrete.
Small cracks caused by shrinkage usually do not present a problem.
Tom meehan a tile installer and owner of cape cod tileworks in harwich massachusetts replies.
With the cracks patched apply a latex modified crack resistant thin set.
In addition to crack suppression the prodeso membrane is designed to hold heating cable in place making the installation of in.
To find out if a concrete slab is clean pour a little water on it in spots.
Concrete can support a lot of weight in compression but is weak in tension.
But larger cracks especially those that are higher on one side than the other may telegraph through the tile and cause it to crack.
Before you install any flooring material over a concrete slab it is important to inspect the slab for defects.
Cut the membrane so it s 1 1 2 times the width of your tiles.
The drying would cause shrinkage or compaction of the dirt possibly enough to create a void under the slab followed by the slab cracking and settling over the area of the void.
Then prime the concrete see photo 2 with the recommended solution consult the membrane manufacturer s literature.
Using a scraper and a wire.
Concrete is similar enough to tile in terms of expansion and it doesn t flex so you don t need crack protection just use a decent polymer modified mortar.
Cracks in a concrete slab are a problem that i run into frequently.
Cracks in concrete floors or slabs occur in poured concrete slabs may be found both in basement and in slab on grade or patio home construction and have a variety of causes and cures that we discuss here as we explain how to repair cracked concrete floors and as we describe slab on grade construction or patio home construction cracks and as we review the diagnosis of cracks in ceramic tile over concrete slab floors.
If you are placing tile on the slab it s important the control joint line up with a control joint in the tile easier said than done.
If tile were set on.
Sweep the concrete floor with a broom to remove any visible debris.
If you watch them tile a commercial center or office building which are always concrete floors you never see them use crack prevention.
Let the primer dry and then apply the membrane photos 3 and 4.
If the water soaks in you re good to go.
In some cases the crack may instead occur in the grout joint.
In some cases i ve seen cracks that are almost 1 4 in.
For small narrow cracks that do not show signs of moisture use concrete filler which can be.
Although it s unsightly it s very easy to fix and it s a much better alternative to a crack in the tile.