What is Flat roof?
A flat roof is an almost horizontal roof closure, commonly found in Switzerland on modern single-family homes, extensions, garages, carports and commercial buildings. Because water does not run off on its own as it does on a pitched roof, a continuous waterproof membrane takes over this job – together with a slight slope that channels rainwater to the drains.
The structure is built in layers: on top of the load-bearing construction (concrete or timber) come the vapour barrier, thermal insulation, a slope-forming layer and the actual waterproofing, such as bitumen sheeting or synthetic membranes. On a green roof or one used as a terrace, further protective and usable layers follow. How these layers work together determines watertightness and service life.
A flat roof is needed when you plan a clear, modern architecture, a roof terrace, a green roof or a solar system – or simply for functional buildings. A specialist firm is required for new builds, renovations, leaks, or when the waterproofing becomes brittle with age.
Pay attention to clean connections to walls, chimneys and drains, functioning drainage and regular maintenance. Common mistakes are insufficient slope, blocked drains and poor workmanship at the connections. Ask for a detailed quote showing the layer structure and warranty; costs depend on area, structure, insulation standard and use.