Just thought I would pass along a tip and discovery..... I needed to install a grab bar in a FG shower - and discovered this item which is carried at Lowes. http://www.amazon.com/Moen-SecureMount-Wall-Anchors-SMA1001CHSMA1001CH/dp/B003DQQYVC It's a neat system for both this application and just about anything heavy you need to fasten to walls when you cannot use studs. I think the carrying weight is 150 lbs per connector, which gives the bar 300 lbs. However, when installed correctly, Moen says it meets the ADA requirements (500 lbs). I ran into a little snag, but I think it's still fine. My plan was to drill through the FG and then through the sheetrock which was maybe 3/4" behind it (the shower enclosure bows out a bit) and then fill the heck out of the space around it with Great Stuff Foam - to stiffen up the wall/shower connection. Well, lo and behold, they didn't install sheetrock or any wall finish (just studs and insulation) behind the FG - but the FG was quite thick, so I still sprayed a bunch of foam behind it in the direction of the studs (maybe it would adhere the two) and then installed the anchors and bar. It certainly seemed more than strong enough when I finished.