Modified Vs Unmodified Thinset - Difference Between Modified And Unmodified Thinset Mortar, Which Is Better For Tiles

2020/11/30 17:49:09

Before your tile installation, you’ve got a lot of decisions to make - the type of backer board and mortar & thinset used for securing tiles to the backsplash, wall or floor. As you shop for the supplies you need, you’ll encounter various kinds of thinset mortar, including some modified thinset and unmodified thinset. You’ll have to choose the best thinset for your tilling job whether it be on shower walls & floors, kitchen backsplash or balcony floors. In this article, we explore the difference between modified thinset and unmodified thinset mortar, as well as how to choose the best thinset for your tile projects.

What Is Thinset & How It Works?

Thinset is a type of adhesive mortar often used to affix stone or tile to various surfaces. It’s basically a mixture of sand, and cement and other compounds to facilitate the hydration process. Thinset is the “Glue” that bonds the tile to the surface to which it is applied, and it does this by growing crystals as it dries and cures. The crystals interlock and penetrate into the surface of the tile and the substrate, bonding it all together. The longer the thinset is able to grow crystals the strong the bond and the strength of the thinset. You might use thinset to install tile flooring in your home, or you may apply it outside if you’re creating an eye-catching tile design along the edge of a pool or as a decorative mosaic.

So what kind of thinset should be used in any given application? Below we are going to deal with modified vs unmodified thinset, choose best thinset for tiles.

Modified Vs Unmodified Thinset - What’s The Difference Between Modified And Unmodified Thinset

- A modified thinset is a thinset that has either polymers added to the powder during manufacturing, or an unmodified thinset that is mixed with a liquid polymer on the job site just before it is to be used. Modified thinset is the most widely used mortar these days and is recommended for most applications and types of tile. Modified thinsets also add an adhesive quality to the bonding mechanism, as well as flexibility, enhancing the strength of the tile assembly. So modified thinset is used to install porcelain tiles on all kinds of substrates that call for a modified thinset.

- Unmodified thinset was becoming a seldom used product until Schluter came along and required it for installing tile to Kerdi and Ditra. Now unmodified thinset is a thinset that has no polymers added to it. The polymers in a modified thinset help it retain moisture so it can grow those crystals, but if the tile does not absorb any moisture, and the substrate is also impervious, then the moisture in the thinset becomes trapped because of the polymers. It need to evaporate for the thinset to dry completely, extending the drying time greatly. The only place for the water in the thinset to escape is the grout lines at the edges of the tiles. So this is where unmodified thinset has an advantage, trapped moisture in this case becomes a benefit. In unmodified thinset moisture that is not consumed by the hydration process will not impede the hardening of the thinset and will eventually escape. The damp cure that the impervious sandwich creates only makes the thinset stronger and promotes a very tenacious bond to the tile.

Which Is Better For Tile, Modified Or Unmodified Thinset?

What type of thinset should be used for tile, modified or unmodified? It first depends on what kind of tiles you are going to be installing and on what kind of surface, you will determine which product you are going to use. Always go with what the tile manufacturer recommends.

Modified thinset, there is cement, there are some other additives which help reduce the drying time, so that the cement where the thinsest stays moist, so it can cure rather than dry out.

The modified stuff has as cement that has some additives but it doesn’t have any latex or acrylic additives. Modified thinset would have. And so it's recommended that if you're putting tile down directly on to plywood then you would need to use a modified so that the plywood doesn't suck the moisture out of the thinset and it doesn't cure correctly. Depending on the kind of tile that you're putting down, if you're putting down large tile you also want to have that thin set to cure in a slower rate rather than using an unmodified type of a thin set on the bags, that'll tell you whether you need to just use water or if you need to add a polymer additive so you know depending on what you're putting down. So if you're doing cement board again because it is on plywood you want to have it modified, so this is going to modify it and plywood. It would be the same thing natural stone porcelain tile, so those would be the cases where you would want to use a modified thinset.

So that’s how thinset works, the comparison between modified thinset and unmodified thinset and I hope this can give a bit of help to decide whether you need an unmodified or modified thinset for your tile installing.