How to Lay a Porcelain Tile Patio Over an Existing Base
Step-by-step guide made from Tidybricks patio restore's YouTube video.
This project demonstrates how to lay a new porcelain tile patio directly over an existing, stable concrete base. The process covers assessing the old patio, establishing new levels for proper drainage, laying the tiles on a mortar bed, and using a tile leveling system for a professional, flat finish.
- Difficulty: intermediate
Safety
- Wear gloves when working with cement and priming slurry to protect your skin.
- Use a dust mask and eye protection when cutting tiles or mixing dry materials to avoid inhaling dust.
- Be careful when lifting heavy tiles and bags of cement to prevent back injury.
Must know before you build
- Verify existing base stability for years; unstable bases cause patio failure.
- Mix mortar precisely: 4 parts sharp sand to 1 part cement for strong bond.
- Prime porcelain tile backs with slurry; non-porous tiles won't bond without it.
- Use a tile leveling system for porcelain to ensure a perfectly flat, professional finish.
- Light-colored tiles show dirt easily; cover freshly laid sections to keep clean during install.
Tools
- String Line
- Spirit Level
- Wheelbarrow
- Shovel (Square-point shovel)
- Trowel (Pointing Trowel)
- Mallet (Rubber Mallet)
- Bucket
- Pressure Washer (optional)
Materials
- Porcelain Tiles (Khaki colored, London Stone)
- Cement (Blue Circle)
- Sharp Sand (four and one mix)
- Priming Slurry (Larsen)
- Stone Dust (2 tons, 210s)
- Tile Leveling System (Clips and caps, Tilers Tools)
Step by step
Step 1: Prepare the Base and Set Layout Lines
The creator demonstrates how to establish the final height, layout, and drainage fall for the new patio. This involves setting up multiple string lines to guide the tile placement and ensure a consistent slope away from the house.
- Establish the Starting Line. Determine the starting point for the tiles. The plan is to start flush with the edge of the existing step area to create one long, straight line across the entire patio.
- Set Height and Drainage Fall. Set up string lines to define the finished height of the patio. Plan for a fall to ensure proper water drainage, dropping the level by 10mm for every 1 meter away from the house.
- Tip: For proper drainage, the patio should have a fall of 10mm for every 1 meter it extends away from the house.
- Set Remaining Layout Lines. Run additional string lines to mark the outer edges and the main courses of the patio. These lines create a grid that will guide the placement of each tile, ensuring the entire layout is square and straight.
Step 2: Lay and Level the Porcelain Tiles
The creator demonstrates the process of laying the tiles. This includes mixing a 4:1 sharp sand and cement mortar, applying a priming slurry to the back of each tile for a strong bond, laying them on a full mortar bed, and using a tile leveling system to ensure a flat, even surface.
- Mix the Mortar. Prepare the mortar bed by mixing sharp sand and cement. Use a 4:1 ratio of sand to cement for a strong, durable mix.
- Tip: Use a 4:1 mix of sharp sand to cement for a strong mortar bed.
- Spread the Mortar Bed. Spread a generous amount of mortar onto the prepared base, creating a full bed for the tile to sit on. Spread it slightly higher than the final level to allow for tamping down.
- Common mistake: Leaving voids or gaps in the mortar bed can create weak spots under the tiles, leading to cracking over time.
- Apply Priming Slurry to the Tile. Before laying the tile, apply a priming slurry to the entire back surface. This is essential for porcelain tiles, as their non-porous nature requires a bonding agent to adhere properly to the mortar.
- Common mistake: For best adhesion, ensure the priming slurry covers the entire back of the tile, right to the edges.
- Lay and Level the Tile. Carefully place the primed tile onto the mortar bed, aligning it with your string lines. Use a rubber mallet to gently tap the tile down until it is level with the string line and adjacent tiles.
- Tip: If a tile sits too low, lift it and add a small amount of mortar beneath it to level the surface.
- Use the Tile Leveling System. Insert the tile leveling clips under the edges of the newly laid tile. Once the next tile is in place, you will add the caps to pull the surfaces flush and ensure there are no lips between them.
- Continue Laying Tiles. Repeat the process of spreading mortar, priming, laying, and leveling for the remaining tiles. Work methodically along your layout lines to build out the patio.
- Watch out: Because the tiles are a light color, they can show footprints and dirt easily during installation. Consider covering freshly laid sections to keep them clean as you work.