Renovation paints and coatings on flat roofs

Bitumen roof surfaces are always and constantly exposed to weather conditions. In addition, high temperature variations, roofs are also subject to photochemical influences. Bitumen materials are therefore subject to high stress in the long term. In the course of the long-term load, the roof materials gradually become brittle. Other materials like fibre cement becomes unsightly and lose their natural protection skin and hence absorbs more water. As a result, lichens and mosses settle down. Through the coating with high-quality synthetic dispersions, the lifetime and improve the aesthetics of such roof structures. Herebelow some examples of renovation works for maintenance purpose of flat roofs with bitumen felts and roofs covered with fibre cement sheets are given.

Step by step


    1. The condition of the substrate and all application details deserve a special attention. These factors are of crucial importance for a successful renovation and maintenance measures. Before roof renovation begins, the roof structure must be examined. The overall construction is to prevent from later damage due to e.g. increased moisture content.


    2. Check damages (cracks, bubbles etc.) in the last layer of the bitumen roof surface. If necessary, use the bitumen waterproofing patching compound weber.tec 911.


    3. Old roof bitumen coverings (bitumen felts or sheets) often show blisters due to trapped air. Remove the humidity inside the blisters by using a dry cloth. Fill the whole inner surface of bubbles with weber.tec 911. Close the open sides and cover them with the same material. Not cracked (closed) bubbles are covered with a bitumen maintenance coating like the whole roof surface.


    4. For a good key of the next coatings apply the bitumen primer weber.tec 902.


    5. As a rule, all primers must be applied by hand with a roller or a brush so as to bind the dust and to obtain best adhesion with the substrate.


    6. Connections to roof outlets and roof penetrations such as domelights, are also critical details. Here, before execution take all measures to ensure their water tightness.


    7. After drying of the primer the full-surface application of the protection, for ex. with the thick bitumen coating weber.tec 905.


    8. After drying of the bitumen coating lay gravel on the roof surface for protecting it from UV rays


    9. Subsequent coating of garage surfaces can be carried out with the 2-comp. reactive, thick and quick-setting  waterproofing coating weber.tec Superflex D 24.


    10. Garages are usually not built in a conventional manner, but as concrete prefabricated units. Advantage: the whole construction is done in precast concrete plants; this includes the roof coating, too. For the maintenance of such roof surfaces use weber.tec 905, weber.tec 960 or Superflex D 24.


    11. In case of fibre cement sheets remove dirt and algae; apply the primer weber.tec 960 V with a solvent-resistant brush; afterwards apply the reflective and protective coating weber.tec 960, using a brush with synthetic bristles, a lamb’s wool roller or an airless gun and air-assisted pump.