Successfully sealing a roof

Roofs protect the buildings below against all external influences. While the sealing of roofs with a clear roof pitch angle is usually less complex, it is flat roofs in particular that repeatedly cause problems with sealing. In the following, we will introduce you to various options for roof sealing.

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

The roof primarily protects the building against weather and climatic influences. A roof is extremely exposed to the effects of the weather. Depending on the roof construction, temperatures of 90 degrees and more can occur in midsummer. In winter, low temperatures, frost and water eat away at the roof fabric.

  • Also read - Sealing holes in the Eternit roof
  • Also read - Sealing the roof connection
  • Also read - Roof terrace: seal the transition between roof and wall

Flat roofs and roofs with a low pitch angle

Roof constructions with no or hardly any roof pitch angle are particularly problematic. The sealing of roofs that are covered with roof tiles or fiber cement panels is also relatively easy. You only have to remove the broken plates or. Replace roof tiles. These roof structures usually form a roof that cannot be walked on or cannot be greened. So the most difficult roofs to seal are mostly flat roofs that can be walked on.

Old and modern sealing techniques for the roof

The classic roof sealing is done with bitumen sheeting (€ 13.99 at Amazon *), which are fused together. But technological progress has not stopped at roof waterproofing products either. This means that you have different techniques for sealing your roof.

  • Bitumen sheeting
  • liquid plastic with reinforcement fabric
  • EPDM rubber film

Seal the roof with bitumen

Sealing the roof with bitumen sheeting is relatively easy. However, you also need a basic knowledge of physical and thermal material properties here. Bitumen, for example, expands very differently than sheet metal. However, they are often used on roof finishes such as walls or chimneys.

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

The bitumen sheets themselves are laid twice. First they are laid lengthways and glued together with the Bunsen burner and bitumen, then bitumen sheets are laid across them 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 correspondingly easy to process. These plastics bond firmly to the subsurface, which can consist of bitumen sheeting, for example. The preparatory work is particularly important for this type of roof waterproofing.

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

EPDM products for roof sealing

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

  • as sealing rings for high thermal loads
  • as hoses for hot water and steam
  • as a roof waterproofing material

Among the products that are suitable for roof sealing, there are not only conventional EPDM foils but also foils that are coated with bitumen on the outside. The EPDM foils have excellent properties as they are required on a roof. They are also laid in a single layer, as they are not connected to each other.

  • they are ozone respectively. UV-resistant
  • high thermal loads are not a problem
  • they are very elastic
  • weather and moisture resistant

Not every roof sealing technique is suitable for every roof. Therefore, you should definitely examine these possibilities with a professional when sealing your own roof.

Tips & Tricks Numerous bitumen roofs are filled with gravel. When it comes to modern sealing products, we hear again and again that, for example, you could do without the gravel when using liquid plastic. That is not right. The gravel serves as a moisture store, protects against high temperatures and UV radiation and is often used to deliberately weigh down the roof.

Depending on which roof waterproofing is installed on your roof, a possible water entry point inside the building does not necessarily have to mean that the water gets into the waterproofing exactly above it. For example, water can move many meters under bitumen sheeting before it seeps into cracks.