William For what it's worth, you may want to check with the rafter mfgr and/or Eng as it is possible they will not allow holes being drilled into them and you could open yourself up to liability issues. I have a structural eng who is insisting I squeeze a construction adhesive (such as LePage PL400) into pilot holes before screwing in the lags when attaching to engineered trusses. Yes, an adhesive, not a sealant. It is to reinforce the strength of the engineered truss that you have just drilled into.
Easy feet or other attachments that have multiple lags per attachment point (kinetic flashings have two lags each) are good because they have better/more holding strength if your lag bolt passes thru the structural attachment (a typical lag bolt will stick out about an inch or more past a 2x4 rafter/truss when laid flat, so your lag has less pull-out strength (thread depth). Multiple lags per attachment remedies this. Or consider installing backboards between the rafters and attaching to them. benn Sent from a 'smart' phone, with touch screen keys. Please excuse shortcuts and typos. > On Nov 6, 2013, at 11:14 AM, "William Miller" <will...@millersolar.com> wrote: > > Friends: > > I am designing an installation on a roof built with engineered rafters. > These are wood I-beams with 2X4s (or smaller) on flat, dadoed to accept an > OSB flange in between. On top is sheeting and then sheet metal. I have > never attached to engineered rafters > > I checked on DPW easy Feet and they look like my best option so far. . Has > anyone else done this before? > > Thanks in advance for all the great idea I you professionals are willing to > share. > > William Miller > > > <image003.jpg> > 17395 Oak Rd. Atascadero, CA 93422 > www.millersolar.com > 805-438-5600 voice > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org >
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