How To Cover Concrete Patios With Slate?

Yes, you can lay slate tile over a concrete patio, but preparation is important. First, check that the concrete base is level, using a spirit level. If it is not level, use a self-levelling compound to make it level and let it dry completely. Next, mix a batch of thinset and spread it over the concrete with a trowel. Then, set the tile into the thinset, ensuring you don't use more thinset than you can cover in 5 minutes. Space the tiles evenly with tile spacers and cut tiles as needed. Allow the thinset to dry for at least 24 hours. After that, mix a batch of grout and squeeze it into the lines between the tiles, ensuring there are no gaps. Let the grout cure for 72 hours and then apply a tile sealer.

Preparing the concrete base

Remove Existing Flooring and Clean the Surface:

Start by removing any existing flooring or coverings on the concrete base. This could be old tiles, paint, or any other material. Ensure that the concrete is completely clean and dry before proceeding to the next step.

Level the Concrete Base:

Use a level, preferably 4-foot or 8-foot, to check if the concrete surface is level. If there are any uneven areas, use a self-levelling compound, such as LevelQuik, to create a smooth and level surface. It is important to let the levelling compound dry completely before moving on.

Apply Thinset:

Thinset is a type of mortar used to adhere tiles to a surface. Choose a thinset suitable for exterior use and spread it evenly over the concrete base using a trowel with notches that match the size of your slate tiles. Make sure you only apply enough thinset that you can cover with slate within 5 minutes.

Set the Slate Tiles:

Carefully set the slate tiles into the thinset, ensuring they are level and evenly spaced. Use tile spacers to maintain consistent spacing between the tiles. Work in small sections to avoid having the thinset dry out before you can place the tiles.

Cut Tiles as Needed:

If you need to fit tiles around edges or obstacles, use a wet tile saw to cut them to the required size and shape. Ensure that you cut the tiles safely and accurately.

Allow Thinset to Dry:

Once you have set all the tiles, let the thinset dry for at least 24 hours, or as recommended by the manufacturer. This will ensure a strong bond between the concrete base and the slate tiles.

Remember to wear appropriate safety gear, including gloves and eye protection, when working with power tools and materials like thinset.

Level the floor

To install slate over a concrete patio, the concrete base must be level. If your patio is not level, you can use a self-levelling compound, like LevelQuik, to make the surface level. You should allow the compound to dry completely before proceeding.

Another option is to use a concrete-levelling technique known as polyurethane foam injection, or polyjacking. This process involves drilling small holes into the concrete patio and pumping polyurethane foam underneath. As the foam expands, it fills any voids under the patio's surface, raising and levelling the slab. Polyjacking is a minimally invasive, quick, and cost-effective solution that is best performed by a professional.

Use thinset

Yes, you can put slate over your concrete patio, but preparation is important.

Use a trowel to spread thinset over the concrete base, ensuring it is even. The trowel should have notches that are the proper size for the tiles you will be using. For example, for 12-inch tiles, use a 1/4-inch-by-1/4-inch-by-3/8-inch trowel.

Once the thinset is spread, set the tiles into it, ensuring you do not use more thinset than you can cover in less than 5 minutes. Space the tiles evenly using tile spacers. Repeat this process over the entire patio.

Allow the thinset to dry for at least 24 hours.

Install the tiles

Before you begin, make sure you have at least 10% extra tile for cuts and waste. It is usually a good idea to have 20% extra so you will have enough tile on hand in the future to fix and replace any tiles that break.

Now, you can start to install the tiles. First, spread the thinset over the concrete base and spread it evenly. You can use a trowel with notches that are the proper size for the tiles you will be using.

Next, take the tiles and set them in the thinset. Make sure that you do not use more thinset than is necessary. Use the spacers to space the tiles evenly until you have covered the entire concrete base. Cut tiles as needed with a wet tile saw. Allow the thinset to dry for at least 24 hours.

Use grout

Grouting is an essential step in installing a slate tile patio over a concrete base. It fills the gaps between the tiles, giving your patio a neat and finished look. Here is a step-by-step guide to grouting your slate tile patio:

Step 1: Choose the Right Grout

The type of grout you choose depends on the width of the grout lines between your slate tiles. For standard grout lines, use an unsanded grout. If your grout lines are wider than 1/8 of an inch, you will need a sanded grout. You can also use a sanded grout for all grout lines, but never use an unsanded grout for wide grout lines.

Step 2: Prepare the Grout

Mix the grout according to the manufacturer's instructions. The consistency of the grout should be similar to that of peanut butter. If you are using a powdered grout mix, add water gradually and mix until you achieve the desired consistency.

Step 3: Apply the Grout

Load the grout into a grouting bag and squeeze it into the grout lines between the tiles. Make sure to fill the grout lines completely, leaving no voids, gaps, or holes. Use a grout float to remove excess grout from the surface of the tiles.

Step 4: Clean the Tiles

After grouting, use a damp sponge to clean the slate tiles. Rinse the sponge frequently to avoid spreading the grout haze. Be careful not to disturb the grout in the lines while cleaning.

Step 5: Cure the Grout

Allow the grout to cure for at least 24 hours, or as recommended by the manufacturer. Avoid walking on the newly grouted patio during this time.

Step 6: Seal the Grout (Optional)

Once the grout has cured, you may choose to apply a grout sealer. This step is especially important if your patio is exposed to the elements or heavy foot traffic. The sealer will protect the grout from stains and moisture damage. Follow the manufacturer's instructions for applying the sealer.

By following these steps, you will ensure that your slate tile patio is properly grouted and will last for many years to come.

Frequently asked questions