Will bougainvillea on my roof be a bad idea?

I have a coup0le of huge bougs growing that I'd like to train up onto the roof so they cascade over the side of my home, but I'm worried they could damage the shingles. we have asphalt shingles up there. Would bougainvilleas do any damage or is it an okay idea? Thanks for any tips!

Anything on your roof other than roof is a bad idea especially with asphalt shingles .. plants can actually lift them up.

X

If the vines made it on the roof, they would catch debris and possibly start rot. It will hold water in place which instead of running off of the roof, the water has more time to work into spots that would normally not be a problem.

yet another problem would be that when the wind blew, it would cause the bougie to "brush" and scrape against the shingles, and remove the grit

You could build some sort of "Rack" that you could attach to the roof that would hold the bougie without allowing it to rest on the rooftop itself? Something out of 2x4s and chicken wire or something?

this is a great picture showing HOW you could do it (popular with a lot of Nantucket cottages), but as X, and Dan have said, it can try to grow under and lift your shingles, and also hold debris and rot.

http://www.flickr.com/photos/paulschw/423358569/

Exactly what i was thinking! Except maybe add some legs of some sort and attach it to the roof (with lots of tar) Just to get it off of the roof about a foot. At least the debris could flow underneath the mass instead of get caught up in it.

oh wow - that roof trellis is a great idea! i think we might try it. thanks so much! :)