Roofing for use during the construction process
A combined vapour control layer and roofing for use during the construction process are laid as early as possible. This can either consist of a polymer-modified bitumen underlay with a polyester reinforcement, or a polyester reinforced PVC membrane (e.g. Protan AM). In both cases the roofing is laid straight onto the roof deck with welded, waterproof joints. If necessary, a layer of “condensation” insulation can also be laid between the roof deck and the roofing.
Roofing and pitch assembly
As soon as there is no longer any need to use the roof as a work platform during the construction period, the insulation and final roofing using Protan SE or Protan EXG can be laid during suitable weather conditions. Pitch assembly should be double-sided with a minimum of 1:40 towards the gutter.
Gutter design
The gutters should be horizontal. They should not be recessed against the parapet in relation the surface of the roof, but should be recessed further in on the roof surface. They should be wide enough so that there is ample space for installing drainpipes. This type of gutter design ensures simpler, and thus more secure, mechanical fastening of the roofing. The roofing will be tightened up better and the surface will thus channel water away more efficiently.
Drainpipes
Drainpipes should be positioned in the gutters at regular intervals of max. 15 m. All drainpipes should have a local recess in relation to the gutters. Horizontal gutters with recessed drainpipes ensure parallel connections in relation to standing water, i.e. if a drainpipe is blocked, the water will be channelled along to the next drainpipe on the horizontal gutter, thus minimising the risk of standing water.