Frequently Asked Questions
about Green Roofs
4. Will the waterproofing be damaged by the plant roots over time?
No, not if appropriate measures are taken. There has been a long standing bias against green roofs due to belief that plant roots will grow into the roof and damage the construction.
Protection: Special root barriers have been designed to prevent damage to the waterproofing and the roof construction. The rootproof layer is integrated into the green roof build-up over top of the waterproofing.
The quality of the root protection layer is extremely important since any leaks or roof damage caused by roots will mean the entire roof will have to be checked, or even replaced, in order to repair the damages.
Reliable root barriers will have a certificate of ‘root proofness’ in accordance with German FLL regulations. The investigation of root protection was established by the FLL as early as 1984 and today the certification is widely accepted by specialists as an authority.
N.B. Root barriers are not the same as waterproofing. In most cases these two elements are completely separate; on occasion suppliers integrate a root barrier into the waterproofing itself.