A brick barbecue needs a stable supporting base before its refractory materials are selected. The support must carry the complete construction and suit the firebox assembly. Check this before building, especially on an existing terrace or where rainwater tends to collect.
Account for the complete structure
Include outer masonry, the refractory firebox, worktop, fittings and any chimney. Size the base from the full drawing. A thin refractory topping does not increase an existing terrace slab's structural capacity.
For a ground-supported construction, assess the ground conditions and foundation arrangement. If the support is unknown, have it assessed before adding the masonry load. Select the heat-exposed materials once this arrangement is established.
Distinguish the foundation from the firebox
Vitcas firebrick can form the working lining of a suitable barbecue. It transfers and stores heat in that role. It does not specify the structural foundation or establish that insulation below the firebox can be omitted.
Outdoor Oven Cement is selected for compatible refractory joints. A jointing mortar does not provide the reinforcement design, supports or foundation build-up. Retain the clearances and movement allowances specified for components that become hot.
Plan where water will drain
Mark the slopes of surrounding surfaces and possible pooling locations. Check the interfaces with the house wall, edging and any roof. The drainage arrangement should keep water from collecting beneath the hot part of the barbecue.
Before adding the next layers, confirm the level, dimensions and readiness of the base according to its construction requirements. Keep photographs and a material record. If cracks appear later, this information helps distinguish a joint defect from movement of the supporting structure.