Final Report Summary

Test Procedure

Green Roof Membranes/Root Barriers were tested for root resistance to Pyracantha and Quack grass in a 2 year greenhouse study based on procedures described in "Investigating resistance to root penetration at green-roof sites" (FLL, 2002) modified as stated in the full report.

Materials Tested

1. HYPROOF waterproofing with Hyload Cloaks in corners. All seams were hot air welded. Hyload Structural Sealent was applied over edges of welded seams.


  1. The HYPROOF waterproofing membrane tested had no adverse affect on growth of the plants over the course of the 2 year test.

  2. Roots did not penetrate through the waterproofing or the heat welded seams over the course of the 2 year test period. One superficial instance of root penetration though a very thin surface layer between apparently contiguous surface imperfections was observed.

  3. Roots did not adhere to the surface of the waterproofing.

  4. There was no evidence of damage to the surface of the waterproofing from exposure to roots, water, fertilizer at normal concentrations, or media over the course of the 2 year test.

  5. Roots penetrated, and root hairs appeared to adhere to the sealant applied over the exposed outside edges of the seams. Roots grew between the sealant and the waterproofing, through the sealant, and appeared to be able to attach to the surface of the sealant. Significant damage to the sealant was evident at the conclusion of the test. The sealant material used (HYLOAD Structural Sealant) should not be relied on to provide waterproofing in a green roof environment.


9976 Rittman Rd.
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