"Green Roof' over SPF system | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

Q&A Forums

Author	Comments
D. Backes Posted: Mar 21, 2008 05:14 PM	"Green Roof' over SPF system Hi Mason, I am looking for any info regarding SPF roofs covered by a planted 'Green Roof' system. Has this been done yet? If this has been done I would guess that possibly the only coating that could handle the constant moisture would be a Polyurea of some kind. I really don't know cause I haven't found anything yet. Thank You, Big D
mason Posted: Mar 22, 2008 10:30 AM	Yes, to install a "green roof" (ie, plants, shrubs, etc) you require, a waterproof membrane under the "green roof assembly" and a drainage system incorporated into the green roof assembly. SPF is water resistant not waterproof. A polyurea coating, asphalt coating, EPDM membrane etc are examples of waterproof membranes. You could use SPF as an insulation under the water proof membrane, but it is not going to take the place of the waterproofing. Contact RCI or NRCA about green roof designs.
D. Backes Posted: Mar 22, 2008 05:25 PM	Thanks for the reply. I'm aware of the need for a waterproofing membrane needed over the foam. The question is what's best in this particularly extreme, constant moisture circumstance; a polyurea? and if so what kind. Or is something better. I know acrylics won't work. Most importantly is there a track record yet with this sort of system used under the live plant medium. I know this is a fairly recent building technique. Has anyone tried this? I have done research and I haven't found a single example of this approach in use. Thank You
D. Backes Posted: Mar 26, 2008 04:36 PM	Well how about it? Is there an example of a green roof built over an SPF system of any kind out there?
Mike McGaughey Posted: Apr 10, 2008 08:20 PM	I would suggest staying away from EPDM and asphalts as the waterproofing membrane-EPDM seams are going to fail-regardless if they are taped or glued or both, and unless you have a seperate root barrier above the epdm roots will grow into the seams. Asphaltic products are susceptible to microbe and root growth into the material-and also require a seperate root barrier. I can not comment on the polyureas. Heat welded PVC membranes are well suited for use as the waterproofing membrane for green roofs-the thicker the better-minimum 70 mil membrane.
mason Posted: Apr 12, 2008 06:47 PM	I know green roofs have been installed over SPF covered with a waterproof coating, (such as a polyurea, but I don't have any field history reports of the applications. Let me know if you find something that we can share with our readers.

Author

Comments

D. Backes

Posted: Mar 21, 2008 05:14 PM

"Green Roof' over SPF system

Hi Mason,
I am looking for any info regarding SPF roofs covered by a planted 'Green Roof' system. Has this been done yet? If this has been done I would guess that possibly the only coating that could handle the constant moisture would be a Polyurea of some kind. I really don't know cause I haven't found anything yet.
Thank You,
Big D

mason

Posted: Mar 22, 2008 10:30 AM

Yes, to install a "green roof" (ie, plants, shrubs, etc) you require, a waterproof membrane under the "green roof assembly" and a drainage system incorporated into the green roof assembly.

SPF is water resistant not waterproof. A polyurea coating, asphalt coating, EPDM membrane etc are examples of waterproof membranes.

You could use SPF as an insulation under the water proof membrane, but it is not going to take the place of the waterproofing.

Contact RCI or NRCA about green roof designs.

D. Backes

Posted: Mar 22, 2008 05:25 PM

Thanks for the reply. I'm aware of the need for a waterproofing membrane needed over the foam. The question is what's best in this particularly extreme, constant moisture circumstance; a polyurea? and if so what kind. Or is something better. I know acrylics won't work. Most importantly is there a track record yet with this sort of system used under the live plant medium. I know this is a fairly recent building technique. Has anyone tried this? I have done research and I haven't found a single example of this approach in use.
Thank You

D. Backes

Posted: Mar 26, 2008 04:36 PM

Well how about it? Is there an example of a green roof built over an SPF system of any kind out there?

Mike McGaughey

Posted: Apr 10, 2008 08:20 PM

I would suggest staying away from EPDM and asphalts as the waterproofing membrane-EPDM seams are going to fail-regardless if they are taped or glued or both, and unless you have a seperate root barrier above the epdm roots will grow into the seams. Asphaltic products are susceptible to microbe and root growth into the material-and also require a seperate root barrier. I can not comment on the polyureas. Heat welded PVC membranes are well suited for use as the waterproofing membrane for green roofs-the thicker the better-minimum 70 mil membrane.

mason

Posted: Apr 12, 2008 06:47 PM

I know green roofs have been installed over SPF covered with a waterproof coating, (such as a polyurea, but I don't have any field history reports of the applications. Let me know if you find something that we can share with our readers.

You need to login to reply to this topic. Please click here to login.