Porcelain Tiles (DITRA, Schluter, Thinset Tips)

DIY homeowners and professional tile installers prefer using DITRA to enhance tile durability by preventing the tile and grout from cracking. DITRA is also ideal for its ease of use compared to its alternative cement backer board.

So, can you use DITRA with porcelain tile? You can use DITRA with porcelain tile to prevent cracking of the tile. The DITRA membrane reduces cracking by absorbing the stress resulting from the movement beneath the tile due to expansion, contraction and shifting.

Whether you are a DIYer or a professional, durability is key for any project you embark on if you are to cut down maintenance costs in the long run. Porcelain tiles expand and contract with temperature changes. Hence, an installation that allows this movement without compromising your tiles is necessary.

You can use DITRA with porcelain tile, given its decoupling performance. DITRA neutralizes substrate movement that could damage your porcelain tile by absorbing the stress from substrate motion underneath, resulting from expansion, contraction and shifting. The result is enhanced durability as your tiles will now be safe from breakage resulting from such processes.

In every floor installation, you expect the substrate underneath to move. If you use DITRA, it will flex with the substrate, preventing this movement from transferring through to the tile and causing the grout to crack. Hence, DITRA neutralizes this motion, similar to how shock absorbers act.

By installing a flexible DITRA layer, your tile will not adhere to the substrate but rather on the DITRA underlayment, mortared on the subfloor. This organization is effective in preventing the motion transmission that causes cracking of your porcelain tiles. For many decades now, tile installers have used sand as the non-rigid layer between the substrate and tile to prevent cracking. DITRA replaces sand with a benefit in performance since it also serves as a waterproof barrier.

One of the places you can use DITRA is with a wood substrate. Using DITRA with wood is ideal given the latter’s susceptibility to moisture and changes in temperature. Wood will expand and contract with changes in temperature and flex when you put heavy loads. Without the presence of a flexible, motion absorbing material, your tile and grout will damage as a result.

Your wood substrate will also damage with exposure to water. You can install DITRA over wood subfloor systems, including 16 or 19 inches on center joist spacing with plywood or single layer OSB for porcelain tile installation, 24-inch joist spacing with plywood or double-layer OSB, and existing vinyl over suitable floor for porcelain.

Can Schluter Be Used With Porcelain Tile?

Porcelain tiles feature durability and ease of maintenance, hence an ideal surface covering. Like other coverings, the performance of porcelain tiles is dependent on the installation method and materials used. Considering Schluter provides various systems for your tile installation featuring uncoupling and waterproofing benefits, you need to know how feasible it is with your porcelain tiles.

You can use Schluter with porcelain, ceramic and stone tile in your interior and exterior system. This spread is easy to use, given its smooth and creamy nature. It is also sag resistant, hence ideal if you want to set your tiles on horizontal and vertical surfaces.

Schluter is a mix of cement, polymer, sand and additives, which gain strength with hydration and film formation when mixed with water. It is commonly used in tile installation, ensuring strength when sandwiching between your porcelain tile and an impervious substrate.

It is available in gray and white, enabling you to select either depending on your aesthetics. Where the color of your mortar affects your home aesthetics, you should pick the white version of Schluter and gray where aesthetics is a non-issue.

When preparing to use Schluter with porcelain, you should acclimate the materials to the room temperature pending installation. This should happen away from direct sunlight or rain as they might skin, or flash set off the mortar. If the installation is under cold temperatures, you should heat the room before, during, and after installation to properly cure the mortar.

Like other installations, you should prepare the substrate by cleaning and leveling it. In the case of concrete substrates, remove wax and oily films if present. If the concrete is dry and porous, moisten it to enhance saturation and prevent premature drying and skinning of the bonding coats. After moistening your concrete, sweep away still water before installation.

After mixing your Schluter in water to attain the appropriate thickness, proceed with the application. Using a trowel, apply a thin layer of the mortar to produce solid contact with the substrate underneath. You can then place your porcelain tiles in the mortar and push them back and forth to collapse any ridges. For dry applications, remove the tile to check for sufficient coverage.

Lastly, observe an open time for the thin mortar set and if it skins over, remove it and start a fresh application. After application, you should maintain temperatures between 40 and 95 degrees Fahrenheit for 12 hours before grouting.

You may need to extend this duration with lower temperatures. When installing grout, stick to the manufacturer’s instructions, and you should protect your surface from moisture or traffic for another 24 hours for the mortar to set. Equally, protect your installation from freezing temperatures for up to 28 days.

What Thinset Is Used for Porcelain Tile?

A thinset will come in handy when you want to install tile over cement, as it is what will make it possible for the tile to stick to the backer board. Thinset is an adhesive made of fine sand, cement and water-retaining agents, with most having latex and polymer additives to increase their bonding strength. Depending on the type of tile you want to install, you should use an appropriate bonding agent to ensure its sets properly; therefore, read on to know the ideal thinset for your porcelain tile.

The modified thinset is used for porcelain tile for an optimum bond. Hence, if you have a non-modified thinset, you should add a latex polymer admixture. During porcelain tile installation, you should note that the bonding materials have minimum and maximum thicknesses.

A very thin thinset will reduce the bond strength, while a thick thinset will offer inadequate compressive strength. A thick thinset may also cause shrinkage, resulting in cracked tiles. Hence, while thickness will vary by manufacturer, you should go for the standard thickness of ¼ inch.

When mixing thinset for porcelain, you should stick to the manufacturer’s instructions for maximum effectiveness. This means double-checking the instructions on the tile you buy for the manufacturer’s product requirements guidelines. When mixing, strive to attain the consistency of peanut butter.

The practices to observe include mixing your thinset and water in a bucket in stages. Mixing in stages implies that you should never put a whole bag in water at once, given its cement ingredient. To mix your thinset, fill your bucket halfway with water and add thinset as you stir until you attain the appropriate consistency. Afterward, leave the mixture to slake and remix before you start using it.

When applying thinset, avoid spreading more than you can work on within a few minutes. This is because the thinset dries very fast once you trowel it out. During application, you should be keen to ensure proper mortar coverage.

Generally, you should attain 80% mortar coverage for interior applications and 95% for exterior and wet environments. Thinset coverage becomes vital with an increase in the tile size, as what works for small tiles will seize working.

During porcelain tile installation with thinset, start by preparing your installation surface. This includes cleaning to remove dirt and dust and leveling. Using the flat side of your trowel, key the thinset into your substrate. Keying in your substrate allows the thinset to bond well with the substrate.

You can use the flat side of the trowel to pull the thinset, with each pull leaving a thin layer behind. While doing this, avoid swirling the thinset. You should also comb the mortar in straight lines, after which you can back butter your tiles. To collapse the mortar ridges, move your porcelain tiles in one direction.

What Can DITRA Be Installed Over?

DITRA boasts popularity, especially in the UK, for its ease of installation. Other benefits include uncoupling the floor cover from the substrate and waterproofing capabilities. Therefore, knowing the substrates you can install DITRA over is necessary to enjoy its array of benefits.

You can install DITRA over several surfaces, including a wood substrate, concrete, floors with radiant heat, and those requiring waterproof installation. Before installing DITRA over these surfaces, you should clean and level the surface and check its compatibility with your materials.

Wood is susceptible to moisture and changes. It will contract or expand with temperature change and exposure to moisture and flex when you put weight on it.  Without the presence of a flexible and motion absorbing material, these motions and changes will damage your tile and grout. Wood will also damage with exposure to water, which is why you should install DITRA over your wood subfloor systems.

Concrete is another challenging substrate requiring installing DITRA, especially with hard floorings like natural stone and tiles. This is given that it can expand up to twice as much as grout and ceramic tile.

This means that if you install your tiles directly on concrete, they will likely crack soon after installation with temperature changes. The concrete subfloors you should cover with DITRA include standard concrete and gypsum concrete over concrete subfloor or wood.

Installing DITRA over floors you intend to use with equipment that is radiant heating is an ideal way of ensuring durability. The heat will cause your materials to expand, and they will cool once you stop heating. With the absence of DITRA, a motion absorbing layer, your tiles will crack.

Lastly, when wood and gypsum concrete substrates absorb moisture, they will expand, damaging the floor covering above them. Hence, install a waterproof barrier like DITRA over your subfloors where there is water flow. This includes your kitchen, bathroom, laundry area and bathroom.

Does Thinset Stick To DITRA?

Using an uncoupling membrane such as a thinset will allow both surfaces to move independently. This flexibility is necessary to reduce stress from expansion and contraction, which is why I will help you know whether thinset can stick to DITRA.

Thinset does not stick to DITRA despite its membrane’s fleece stick bonding well with the substrate. Hence, you will notice voids between the pillars holding your tiles up. If you apply lateral stress on such a surface, your tile and the thinset layer will move independently of the slab or subfloor.

Since DITRA will not stick to thinset, if you want to set it over gypsum or concrete, consider an unmodified thinset mortar meeting the ANSI A118.1 requirements, as recommended by Schluter Systems.

Manufacturers do not recommend modified thinset on DITRA when setting tiles because the mortars must air dry for proper curing. By sandwiching it between porcelain tile and DITRA, which are two impervious layers, drying may take up to 60 days in some instances as air can only pass through the open grout joints.

Using modified thinset with DITRA is also not recommended due to unpredictable results caused by the membrane inhibiting drying. For instance, polymer leaching, and leaking will occur if you use a modified thinset on your bathroom floor and use the shower before the mortar cures properly.

Wrap Up

Your porcelain tiles will expand with changes in temperature, which is why you should use DITRA with these tiles for its decoupling performances. This way, the substrate movements that could otherwise damage your tiles will be absorbed by DITRA, protecting your tiles from breaking. You can use Schluter with your porcelain tiles to set your tiles properly, especially with vertical surfaces, given its sag resistance.

Among the surfaces you can install DITRA over include wood, concrete, floors requiring waterproof installation and those with radiant heat. You should prepare these substrates by cleaning and leveling them before installation.

When it comes to your thinset choice on porcelain, consider the modified adhesive. You can also use the non-modified thinset, but you should add a latex polymer admixture. Finally, thinset does not stick to DITRA and will leave voids between the pillars holding your tiles. Hence, consider an unmodified thinset to set DITRA over your concrete substrate.

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