How to finish expansion gap on porch?

gdjdjdja737

I’m planning on tiling the front porch and the concrete slab in front. The concrete slabs have a bullnose edge and the expansion gap is 10mm wide. Is the best way to silicone the expansion gap between the tiles? Seems like a wide expansion gap to silicone or is there another way to make it look tidy?

MitchellMc

Welcome to the Bunnings Workshop community @gdjdjdja737. It's brilliant to have you join us, and many thanks for your question about tiling over an expansion gap.

When tiling over a concrete slab that has an expansion gap, it’s important to ensure the joint transfers through to the tiles. You should tile up to the edge of the expansion joint on either side, but do not cover the joint itself with adhesive, as this could cause the tiles or grout to crack if the slab moves. Make sure the grout lines of the tiles align with the expansion joint above, so the joint appears straight and continuous. Instead of using grout directly in this area, fill the joint with silicone, which is flexible and can accommodate movement. The tile-to-tile gap over the expansion joint doesn’t need to be as wide as the slab’s full expansion gap; for example, you could leave a 5mm gap between the tiles and fill that with silicone, allowing the expansion joint to function properly while keeping the finish neat.

I've created a rendering below to illustrate.

Please let me know if you have any questions.

Mitchell