What is used to waterproof a chimney?

Leaking chimney flashings are among the most common causes of moisture damage to roofs. The challenge is that the junction between the chimney masonry and the roof covering is constantly moving due to wind loads, temperature changes and settlement.

ALLESDICHT is suitable for this application because its elastic, crack-bridging rubber membrane permanently accommodates these movements. It adheres to typical chimney substrates such as brick, concrete, sheet metal and fibre cement, provided they are clean, dry and sound. At the junction between the chimney and the roof surface, reinforcing scrim is embedded into the liquid-applied membrane to strengthen this highly stressed detail. The waterproofing is carried sufficiently high up the chimney and connected to the roof waterproofing at the abutment.

As a rubber-based waterproofing, ALLESDICHT is surface-resistant up to about 100 °C. On the outside of a chimney, especially near the top, these temperatures are usually well below this level with conventional heating systems, so waterproofing is generally possible without difficulty. The actual surface temperature is the decisive factor. If in doubt, a chimney sweep can advise.