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D. Backes
Posted: Mar 27, 2008 12:15 PM
SPF under green roof
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 and possible root damage would be a Polyurea . I really don't know cause I haven't found any examples yet.
Thank You in advance,
Big D
Gerry Wagoner
Posted: Apr 03, 2008 07:22 PM
I wouldn't do it, unless the roof was very well drained indeeed. After that, I still wouldn't do it. :)

D. Backes
Posted: Jan 21, 2010 10:14 AM
Well almost 2 years later, still wondering if anyone has seen, heard of, or better yet installed one yourself. I've seen spec's by VFI though I don't know if it was actually installed.
Dennis Davidson
Posted: Jan 21, 2010 02:45 PM
There are some specialized urethane coatings designed for continuous submersion but they are very expensive and must be installed correctly. You won't find these coatings at the roof material suppliers. I had a foam roof on a school coated with a urethane coating that was damaged during construction of a large addition (long story). The damage caused the roof to sag bad. It left a pond about 10' X 15' and was 12" deep in the middle. It stayed that way for almost 10 years, never dried out and never leaked. They finally hired me to fix it last year. So even the standard urethane roof coating is capable of full time moisture. Coatings are my specialty so let me know if you find someone willing to have one installed. There's only one building I know of with a "planted" roof, but it has an EPDM on it.
D. Backes
Posted: Jan 21, 2010 04:41 PM
Thanks for the reply Macs.
My thought has been a polyurea coating, and this has been born out by the fact of VFI's spec for 100 mils applied over the foam. It makes perfect sense to me but I don't see any movement in that direction. I have'nt seen any examples yet. I don't think I'm that far ahead of the curve.
Posted: Feb 16, 2010 11:07 PM
Well at least one has been done and it seems Dow has a product for it.


Dancey explains, “After several months of research and evaluating comparative systems, Dow’s Verdiseal polyurea membrane was chosen for this project.”

Dow’s website describes Verdiseal as “an elastomeric membrane developed for use in verdant roof gardens, such as green roofs and plaza decks that help improve environmental aesthetics and urban air quality. It provides a waterproof, seamless coating that can be quickly and easily applied and readily accommodates complex roof configurations and protrusions.”
Dennis Davidson
Posted: Feb 17, 2010 08:54 AM
There are plenty of "coating systems" that can be used for planters and recreational or pedestrian roofs. These systems have been around for a long time. But none that I know of have been used over spray foam for an actual "Green Planted Roof". However, there are SPF coated roofs for pedestrian use like walkways and outside recreation areas, but they have extensive drainage systems and special traffic bearing surfaces. The typical roof structure of this type is installed using foam board stock, EPDM rubber and concrete pavers. Until there's more interest in "Green Planted" roofs I don't think any foam suppliers will be willing to get involved in it.
Tim Wojnarski
Posted: Feb 17, 2010 02:14 PM
If you take a look at what a green roof is, it's nothing more than a really fancy IRMA. In my market (MD/VA), the king of green roofing is hot rubberized asphalt. No matter which system you look at, they are all pretty much the same from a waterproofing standpoint. The membrane is fully adhered to the deck with various layers of slipsheets, protection boards, drainage mats, root barriers and insulation on top of the membrane. Then you finally get to the "green" part with the dirt, plants, irrigation, pavers, etc. Personally, the only place I would see this with SPF as an even remote option would be a renovation project where the existing hot rubberized asphalt would not have to be removed. Could be enough of a cost savings to justify the SPF. Have I ever done one? No, but it's fun to think about.

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