Why is my Floor Grout Cracking? It is placed there specifically to prevent your tile from moving. Moving tile leads to cracking grout. But you knew that. How to Prevent Tile Cracks. There are several methods you can use to prevent tile cracks. Networx Tile Contractors: My Floor Tile Is Cracking.

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A tile installation is only as good as the foundation it is built upon. Concrete is a common substrate for installations that are designed to hold up in public spaces. When initially preparing the concrete mix for placement, water above the amount necessary to hydrate cement is required in the mix for proper workability and finishing.

The extra water is called “water of convenience.” After newly-placed concrete hardens, it begins to shrink as the water not consumed by cement hydration (water of convenience) leaves the concrete. This is known as drying shrinkage. Shrinkage of the concrete can cause the slab to crack.

Contraction joints are cut into the surface of the new slab to control where the cracks occur. If the placement of the joints isn’t correct, cracks can randomly develop throughout the slab. When contraction joints are installed properly, the tile layout doesn’t always align with the locations of properly installed joints. Tiles installed over a cracked slab or continuously over contraction joints are subject to cracking, threatening durability and aesthetics of the installation. The use of crack isolation membranes, prevents tile from cracking over concrete that is subject to in-plane movement of cracks that resulted from drying shrinkage. This same crack prevention capability is now also available in crack isolation mortars, enabling tile bonding and crack prevention in one step. Tonehammer requiem. With advancements in technology, some products in both categories (membranes and mortars) allow continuous installation over contraction joints as well as shrinkage cracks.

However, expansion joints are through-slab separations that allow the adjacent concrete edges to move freely from one another both horizontally and vertically. Expansion joints must continue through the tile work. James Mcguire - November 19, 2015 Once added new concrete over old in a carport that had poor drainage. Added an apron out front to ease entry into the carport. Since the apron was not over old concrete, I used the reinforcing wire mesh in that area. Re: Tom Plaskota - November 20, 2015 Thanks for sharing. Sandrine - January 13, 2017 I bought a newly-built house and recently l noticed a long crack going through several floor tiles into one line.

Do l need a surveyor or structural engineer to evaluate what went wrong? Re: Tom Plaskota - January 13, 2017 It is possible that the tile wasn’t installed with a crack isolation membrane underneath the tile, and therefore substrate cracks telegraphed through to the tile. You may start with tearing out the few tiles that are cracked and seeing if the concrete substrate is cracked. If there is a substrate crack that is flush on both sides with one side not higher than the other, our TEC HydraFlex Crack Isolation Membrane products can help.

For crack isolation applications, apply the membrane at 50 mils wet film thickness over the entire surface. Pre-fill all concrete cracks, control joints and plywood gaps up to 1⁄8' (3 mm) wide with membrane prior to application. For expansion, isolation and construction joints continue joints through the tile installation in accordance with Installation Method EJ171 in the Tile Council of America handbook.

Treat dynamic cracks (subjected to movement) greater than 1⁄4' (6 mm) wide as expansion joints. Feel free to call my Technical Support Team for assistance at 1-800-832-9023.

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