Welding membranes for roof waterproofing consist of woven fabrics made of glass fibers, polyester or jute that have been soaked in bitumen. This "roofing felt" for welding is laid one or more layers depending on the place of use and expected load.
Sanded or talc-coated welding paths usually form the lower layer. For covering the laying of welds with slate share is common, which ensures resistance to UV light. Metallic admixtures such as copper or aluminum are used for planted roofs or as vapor barriers.
1. Laying direction
Similar to other roofing felt, the welding sheets are laid from the bottom to the top of pitched roofs. On flat roofs, attention should be paid to the subsequent access during laying in order to avoid having to walk on the freshly welded sheets.
2nd layer by layer: Pay attention to the weather
If several layers of welding tracks are to be laid, each layer must first be completed individually over the entire roof area. Here is to pay attention to the time and the weather, so that a first only simply coated layer does not get wet or damp.
The welding lines can only be laid in complete dryness and need sufficient time to cool down after heating. If moisture is present or a lower layer has not yet cooled down, the welding paths can later become detached again and become permeable. Das 3. Applying the Welding Lanes
When welding tracks are laid professionally, the applied bitumen coating is already liquefied with a welding machine during the rolling of the individual lanes.
The different welding tracks contain different carrier materials, which have special properties. When purchasing, care must be taken to ensure that the selected welding tracks are suitable for the corresponding cover layer.
When heating, the bituminous layer may only be superficially liquefied and excessive heating must be avoided to prevent evaporation or burning of the bitumen.
Tips & TricksInbetween the welding track and a subfloor or wooden substructure, a nailboard must be applied to prevent the wood from igniting.