Concreting the seat foundation

Hello!

We have a seating area of about 4x8m directly next to the house. After several years, the ground (interlocking stones) at the sides has slightly sunk. Therefore, we have considered removing the interlocking stones, concreting the base, and having slabs laid so that later a conservatory could possibly be installed.

Who can provide information on what we need to pay attention to when awarding the contract (e.g. how thick should the concrete layer be, is a protection needed between the concrete and the house facade, how much could the whole thing approximately cost)?

Thank you very much!

Hello, The thickness of the slab results structurally from the reinforcement and the concrete cover (this is the concrete layer over the reinforcing bars); the slab will be about 14cm thick. When awarding the contract, make sure that the concrete slab is waterproofed before laying the tiles (a bitumen sheet would be good). The waterproofing has the purpose of preventing water entering through the tile joints from penetrating the concrete slab; otherwise, the water would over time dissolve lime components, which then show up as white spots in the tile joints - it doesn't look nice and is quite stubborn to clean. The tile covering must be laid with a slope (at least 2%) away from the house so that water drains outward and not towards the house. For price determination, it is best to invite two or three craftsmen who will each submit their offer to you. Technical matters can also be well discussed this way.