What’s under your feet (or however you get around) is as important as anything when it comes to home. That’s why this fall, we collaborated with The Home Depot on an A to Z guide that’ll give you the confidence to make flooring choices you’ll love. Check out the A to Z handbook here.
Even though you don’t see it after installation, the quality of any tiling project rests on mortar, the thick cement and sand adhesive that secures tiles to a home’s subfloor, or substrate. Selecting the right mortar is paramount, especially if you’re planning to DIY a tile floor. You might not want a version that dries so fast you can’t get tiles secured in the right place, but you also don’t want a process that drags on so long that you’re quite literally watching the floor dry.
Fortunately, there’s a type of mortar out there for every tiling project — many of which are available at The Home Depot — as well as some handy quick-setting products that don’t require it at all.
The makeup of mortar
Made out of cement, sand and a water-retaining agent, mortar keeps tiles firmly grounded, typically with a layer between a 3/16” and a 1/4”. Its mud-like texture also creates a connective barrier between the tiles and the subfloor, ensuring that excess moisture doesn’t leach through.
Much like grout, which fills the gaps in between tiles, mortar is available in mix-on-site or pre-mixed varieties, and which version you choose often depends on the space you’re working with and the type of tile that’s being used. (Just remember that once you mix up the dry version, you’ll have to move quickly to use it all or discard what’s left over!)
Modified vs. unmodified
The most common type of mortar used for indoor flooring projects is a modified thinset mortar. (You’ll find many companies and contractors use the terms “thinset” and “mortar” interchangeably: confusing, but common.)
The Layers of Tile Flooring
Made with plastic or latex polymers mixed in — which gives the mortar increased long-term performance and bond strength — modified thinset mortar repels mold growth and can really stand up to the elements with its flexibility: no shrinking or contracting based on changes in temperature or moisture levels. These properties make modified thinset mortar ideal for flooring areas of the home that will have to stand up to splashing or pooling water, like bathrooms (or tiled shower floors), laundry rooms and mud rooms. A soaking wet dog plodding in from the rain won’t even phase it.
Unmodified thinset mortar doesn’t have additional polymers in the mix, but is the mortar of choice in some specific circumstances, like when installing natural stone or when you’re working with a product that uses a moisture barrier over the subfloor. Both modified and unmodified thinset can also even out any small imperfections in the substrate before the tile goes down and is ready to be grouted.
For larger tiles, a medium-bed mortar is the way to go, which can be applied up to ½” thick and creates a significant barrier between the substrate and the tile itself, useful if a settling foundation shifts or cracks over time. Due to its use of coarse sand, though, medium-bed mortar takes significantly longer to dry than thinset: up to 72 hours.
Make it quick (setting)
So, when does it make sense to use quick-setting mortar, or no mortar at all?
When it comes to quick-setting mortar, small jobs like a shower floor and repairs are a great place to start for homeowners. The sweet spot for product quality and fast installation is a fortified, quick-setting mortar like SpeedSet thinset mortar, which dries in roughly six hours time.
(It’s worth pointing out that one of the most prominent “quick dry” options is epoxy tile mortar, which is water and chemical resistant with shock-proof bonding ability. But this product’s greatest strengths is why it’s typically only used by professional installers: the mortar sets completely in about two hours once spread, and its “pot life” — how long it can stay in the bucket without hardening — is only about 45 minutes.)
And then there are new, innovative products like Quictile by Daltile, which flips the whole notion of mortar on its head.
This type of tile uses three simple steps and what is known as the “floating floor” method to give you brand new flooring in as little as a day. Simply lay down the correct foam underlayment on top of an existing hard surface, click together the tiles of your choice (like marble-looking porcelain or driftwood-esque porcelain), seal with grout, and it’s a wrap. No need to rip out old flooring, no waiting on mortar to dry, and no racing against the clock if it starts hardening too quickly.
Whether you’re quick-setting, going a more traditional route, or trying a time-saver like Quictile, it bears repeating (yet again!) to always follow the manufacturer’s guidelines, and make sure to measure properly to ensure the tile doesn’t end up obstructing any doorways or thresholds. Your tile (and sanity) will thank you.