We recommend the using the Black Liquid Rubber Waterproof Sealant.
In this Video, you can see the process of building up a ply system. I'd recommend doing a 2 ply (each ply perpendicular) and building your final membrane on top.
Basic process will be:
- Ensure a clean , dry surface.
- Bridge seams, joints, gaps, vents.... with Liquid Rubber Seam Tape
- Build your ply doing the 3 Course System of applying Black Liquid Rubber Waterproof Sealant, then 40" Geo-Textile and Black Liquid Rubber Waterproof Sealant. Do the next ply the same way but perpendicular.
- Apply the rest of the material on top to build your final thickness.
- Apply a weed barrier before installing your Green Roof.
For 400 sq ft, materials: