Extensive green roofs require comprehensive waterproofing at the roof deck level to ensure reliability. At PermaRoof Commercial’s green roof division, we understand the importance of waterproofing and how critical both the choice of system and the installation process can be to the longevity of the project.

Specifying with RubberGard EPDM on extensive green roofs gives contractors greater flexibility as it can be installed in larger sheet sizes than other systems, minimising seams and increasing the overall integrity.

Should seaming be necessary when installing RubberGard EPDM on an extensive green roof, there is a specific process that should be followed. Please find our step by step guide below and get in touch if you need further installation or specification assistance.

How to seam RubberGard EPDM for an extensive green roof

Make a standard seam with QuickSeam Splice Tape and QuickPrime Plus as per the Elevate Technical Guidelines. On top of the finished QuickSeam Splice Tape seam, prepare the seaming area with QuickPrime Plus.

According to FLL/EN 13948 testing, the field-fabricated seams of a RubberGard EPDM roofing system for extensive green roofs must be covered with Pourable Sealer S-10. This product is a two-component sealer. Pour part B in part A and mix thoroughly using a drill with a mixing blade. Mix until the material is uniformly black in colour. Pourable Sealer should be used within 30 minutes after mixing.

Carefully pour the mixed Pourable Sealant centrally over the seam. Coverage rate: app. 20-25 lin.m per gallon

The Pourable Sealer must be spread equally and centralized over the seam edge ensuring a min. width of 50 mm and a min. thickness of 5 mm in the centre, above the exposing tape.

A specially designed tool can be used to facilitate the installation. This way a coverage of approx. 20-25 lin.m per gallon of Pourable Sealer may be achieved.

Installation Notes – important

Note that T-joints don’t need to be covered with a QuickSeam FormFlash patch, as the Pourable Sealer will close the capillary. If a QuickSeam FormFlash patch is installed, its entire surface needs to be covered with Pourable Sealer as well.

Pourable Sealer must be installed on horizontal seams only (up to the QS FormFlash angle-change patch). At roof perimeters and around details a green-free zone (min. 30 cm) should be maintained using e.g. rounded gravel.

Prior to the installation of the extensive green roof, we strongly recommend performing a water test of the EPDM Roofing System. Install the green roof as soon as the waterproofing installation is completed. Please note that the Pourable Sealer may begin to crack when exposed to sunlight for too long.

Extensive green roof systems only require basic maintenance, such as periodic removal of undesirable plants (weeds etc) and removal of any leaves or debris which could cause blockage of gutters and drains. Notify the building owner to establish a periodic maintenance.