There are products for connection to sheathing/decking only. It might not answer your question directly, but...
Check out the Eco-Fasten Eco-44/65. It was designed for SIP panels and low-slope membrane roofs. We have fastened these to wood and steel decking only. They have 6 or 8 holes for fasteners. If flashed properly, it's a plausible option on composite roofs even through the manufacturer does not market it for that use. There is plenty of data out there for screw pull-out strength in OSB and plywood from fastener manufacturers. Maybe Eco-Fasten can point you to the right fastener type recommended (required?) for their product in a variety of substrates. Another good example is the VersaBracket from S-5!. On a 5V metal roof with vertical trusses there is no way to hit trusses that land under the V crimps, so blocking would be necessary for other methods (like the EcoFasten SimpleSeal). If you can't access the attic, you are out of luck for blocking, so the Versabracket is an option we have used, even in the high velocity hurricane zones in Florida. S-5! even publishes load test data in 1/2" OSB for Versabrackets using the fastener (14 x 1.5" TYPE 17 w/washer 3/8" HWH). The Versabracket-67 has an allowable load normal to the deck of 181 pounds. That usually requires 12"-32" spacing depending on roof zone around here. It's a lot of brackets, but they are pretty cheap. For tile roofs, tile hooks usually allow an easy way to find a truss, but if the trusses go the wrong way, blocking is the only option I am aware of. Comp roofs - I can't imagine why it couldn't be done from an engineering standpoint, but the flashing is the more difficult question in my mind. Jason Szumlanski Florida Solar Design Group On Tue, Apr 28, 2015 at 4:50 PM, <[email protected]> wrote: > Friends: > > > > I’d like to bring up the subject of fastening roof mounts directly to roof > sheeting. We have occasionally a need to do a roof mount on tile or comp > roofs where we cannot guarantee finding rafters in a useable locations. We > researched this in 2013. > > > > We discovered the DPW EZ feet product. When we researched further, the > manufacturer of the screws being used told us that the screw had not been > tested with standard roof sheeting materials. The need has occurred again > and we want to renew our search for options. > > > > Are there any direct-to-sheeting attachment options that have been > certified for suitability in North America? > > > > Thanks in advance. > > > > William Miller > > > > > > [image: Gradient Cap_mini] > Lic 773985 > millersolar.com <http://www.millersolar.com/> > 805-438-5600 > > >
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