Seal a roof successfully

Roofs protect the underlying buildings against all external influences. While the sealing of roofs with a clear roof pitch angle is usually less expensive, it is particularly flat roofs that repeatedly cause problems when sealing. Below we present you various options for roof sealing.

A roof not only protects, it also has to be very resistant

The roof protects the building against weather and climate influences. A roof is extremely exposed to the weather. Depending on the roof construction, it can reach temperatures of 90 degrees and more in midsummer. In winter, low temperatures, frost and water on the roof substance.

Flat roofs and roofs with low inclination angle

Particularly problematic are roof structures with little or no existing roof pitch angle. It is also relatively easy to seal roofs that are covered with roof tiles or fiber cement boards. All you need to do is replace the broken panels or roof tiles. These roof structures usually form a non-accessible or non-plantable roof. So the hardest to seal roofs are mainly walk-flat roofs.

Old and modern sealing techniques for the roof

The classic roof seal is made by bituminous membranes, which are fused together. But technological progress has not stopped before the roofing products. Thus, you have different techniques for sealing your roof.

  • bitumen sheets
  • liquid plastic with reinforcement fabric
  • EPDM rubber sheet

Seal the roof with bitumen

Roof waterproofing with bituminous membranes is relatively easy. However, you also need a basic knowledge of physical and thermal material properties here. For example, bitumen extends very differently than metal sheets. But they are often used on roof tops such as walls or fireplaces.

At such transitions, you must use sealing materials that act like an elastic bridge and compensate for the different dimensions without tearing. You will find numerous products in specialist shops, such as special PU sealing cartridges that you can use. Often you can still insert an additional stabilizing mesh mat.

The bituminous membranes themselves are laid twice. First they are laid longitudinally and glued together with the Bunsen burner and bitumen, then bitumen membranes are laid across again. This ensures that the roof is really absolutely tight.

Seal the roof with liquid plastic

The most common products are one-component products, which are accordingly easy to process. These plastics bond firmly to the substrate, which may consist of bituminous membranes, for example. The preparatory work is particularly important in this variant of the roofing.

If there are still dirt particles on the surface, the liquid plastic can not connect here and means a potential risk point. Therefore, you must carry out the preparatory work strictly according to the respective manufacturer's instructions. Partly for this technique a reinforcement fleece is offered, which you can incorporate into the liquid plastic.

EPDM roof sealing products

EPDM products refer to synthetic rubber products (ethylene-propylene-diene rubber) made of elastomers (rubber). You will find these products in numerous areas.

  • as sealing rings at high thermal loads
  • as hoses for hot water and steam
  • as a roofing material

In the products that are suitable for roofing, there are in addition to conventional EPDM films also such films that are coated on the outside with bitumen. The EPDM foils provide excellent properties needed on a roof. They are also single-layered, because they do not connect to each other.

  • they are ozone or UV resistant
  • high thermal loads are no problem
  • they are very elastic
  • weather and moisture resistant

Not every roofing technique is suitable for every roof. Therefore, you should always consider these options when sealing your own roof with a specialist.

Tips & Tricks

Numerous bituminous roofs are filled with gravel. When it comes to modern sealing products, it is often said that, for example, you could do without the gravel when using liquid plastic. That is not right. The gravel serves as a moisture storage, protects against high temperatures and UV radiation and often serves as deliberate weighting of the roof.

Depending on which roof seal is installed on your roof, a potential water entry point inside the building does not necessarily mean that the water gets into the seal just above it. For example, water can travel many meters under bituminous sheets before it seeps into cracks.

Video Board: DIY: How to fix, repair, protect and seal a felt roof and flat roof using Everbuild Black Jack