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Renovator12321 Feb 2026 11:59Hello everyone,
I could use your collective intelligence:
For unknown reasons, the previous owner of my house had the terrace redone shortly before selling, but chose ugly exposed aggregate concrete slabs as the surface. Since the gravel bed underneath is still in great condition, I just want to replace the 5 cm (2 inches) thick exposed aggregate slabs with something nicer.
Kann offers exactly what I'm looking for with their BetonPlus line. These consist of a 2 cm (0.8 inch) porcelain stoneware tile glued onto a 3 cm (1.2 inch) concrete slab. Unfortunately, they are quite expensive at over €100 per m².
My idea:
Buy cheap (exposed aggregate) concrete slabs in 3 or 4 cm (1.2 or 1.6 inch) thickness from a hardware store. Then brush the top surface with a primer and apply a 1 or 2 cm (0.4 or 0.8 inch) thick porcelain stoneware tile of choice using flexible adhesive. After drying, lay them loose on the gravel bed.
Is this a bad idea or an affordable market gap?
I could use your collective intelligence:
For unknown reasons, the previous owner of my house had the terrace redone shortly before selling, but chose ugly exposed aggregate concrete slabs as the surface. Since the gravel bed underneath is still in great condition, I just want to replace the 5 cm (2 inches) thick exposed aggregate slabs with something nicer.
Kann offers exactly what I'm looking for with their BetonPlus line. These consist of a 2 cm (0.8 inch) porcelain stoneware tile glued onto a 3 cm (1.2 inch) concrete slab. Unfortunately, they are quite expensive at over €100 per m².
My idea:
Buy cheap (exposed aggregate) concrete slabs in 3 or 4 cm (1.2 or 1.6 inch) thickness from a hardware store. Then brush the top surface with a primer and apply a 1 or 2 cm (0.4 or 0.8 inch) thick porcelain stoneware tile of choice using flexible adhesive. After drying, lay them loose on the gravel bed.
Is this a bad idea or an affordable market gap?
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nordanney21 Feb 2026 12:32If it fits down to the millimeter, then give it a try. The problem is that if even the slightest bit of moisture gets between the two panels (which can easily happen), frost can cause everything to crack. Also, you need to apply exactly the same amount of adhesive to all the panels; otherwise, you’ll end up with bonded panels of varying thicknesses – the base surface is level after all.
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MachsSelbst21 Feb 2026 14:17You won’t be able to achieve the same level of precision as Kann does in their production. Plus, it’s a lot of work for what will probably be a rather mediocre result. Concrete slabs also have tolerances; sometimes they are 3.1cm (1.22 inches), sometimes 2.9cm (1.14 inches) thick, rarely exactly 3cm (1.18 inches).
100 EUR/m² (per square meter) is not that expensive after all. You don’t get the materials for your DIY project for free either...
100 EUR/m² (per square meter) is not that expensive after all. You don’t get the materials for your DIY project for free either...