Chris Bronze Star Construction Lags are what I use. I usually use the 5/16" and 1/4" with the most thread I can into the truss without popping out the other side. I have dropped to #7 with more penetrations if the truss warranted it.
http://www.screw-products.com/star-drive-construction-lag-screws.htm Here is their strength tests for 5/16", very comparable to lags. I tend to be pretty conservative and use a 2x - 2.5x strength tests safety factor with almost all my fasteners, especially blind attachment to trusses. Full test results are available. http://www.screw-products.com/specs.htm I have had luck with Cannon gasket for butyl or EDPM washers, use .75 dia outer with dia of fastener inner about .25" thick. About $.15 each for 1000, about half that for 2500. Can order direct online. Buytl to me works better since it flows well when tightened. http://www.cannongasket.com/ I believe there are several manufacturers making these types of screws now, so there may be other sources. Hope that helps! Bill On Tue, Jul 3, 2012 at 6:43 AM, Chris Mason <cometenergysyst...@gmail.com>wrote: > Bill, > Can you provide a link to the product you are using - I found a lot of > screws on that site but none called "structural". > > Thanks > > Chris > > On Mon, Jul 2, 2012 at 7:08 PM, Bill Hoffer <suneng...@gmail.com> wrote: > >> Mark >> >> Lags for me are old hat after using the newer structural screws. I get >> them local from www.screw-products.com although I know there are more >> companies out there that make them for the Structural Insulation Panel >> industry. Thinner than lags with comparable strength, they drive easy with >> no predrilling, and are less likely to blow out a truss. Come in many >> different lengths and use a special star head with a built in washer. I >> use thick butyl tape on the foot and a small rubber washer on the screw >> head , together they work great! If you want a little more security a dab >> of the appropriate sealer in the foot slot before finally tightening it >> down works too. Only way to go on corrugated metal roofs where there is no >> real option for flashing. >> >> Bill >> >> >> On Mon, Jul 2, 2012 at 3:40 PM, <m...@hurshtown.com> wrote: >> >>> My 18V Milwaukee cordless hammer drill has no trouble driving a 5/16" >>> lag into anything I've ever encountered. >>> If you put the lag anywhere near the middle of the rafter it won't >>> split. If it splits, it must be some cheap stuff from Home Depot. >>> Only an engineer with no practical experience would insist on a pilot >>> hole and the resulting reduction in holding strength. I'm assuming the IBC >>> consists of a bunch of bureaucrats that value control over common sense. >>> In this instance flashing offers no benefit, and may even be >>> counter-productive if incorrectly installed and it causes rain to collect >>> under it. My experience is in northern Indiana where it does rain and the >>> wind does blow. (Record 91 mph winds last Thursday.) Less severe weather >>> than Michigan, but close. >>> I use the best silicone caulk Menards has to offer. I've never worried >>> about compatibility. It definitely won't dry up and crack away like the >>> black roof cement some swear by and insist on. 15+ year old silicone caulk >>> is yellowed a bit but that's the only change. >>> If the silicone and shingle aren't getting along, I've never heard them >>> complain. >>> >>> Mark >>> (Disclaimer: Portions of the preceding are the opinions of the author.) >>> >>> -------- Original Message -------- >>> Subject: Re: [RE-wrenches] L feet no flashing in shingle roof >>> From: Dave Click <davecl...@fsec.ucf.edu> >>> Date: Mon, July 02, 2012 10:29 am >>> To: re-wrenches@lists.re-wrenches.org >>> >>> I always thought that installing lag screws was tough enough with pilot >>> holes- I should hit the gym. I'm not a structural PE, but I think that >>> not drilling pilot holes violates the American Wood Council's National >>> Design Specs and therefore violates the IBC too. I would imagine that >>> you'd be much more likely to split your trusses. IBC also requires >>> flashings be used but at least around here inspectors never ask for it >>> (which makes sense- as you all know, Florida never sees wind or rain, >>> and definitely not at the same time). What silicone do you use that's >>> compatible with asphalt shingles? >>> >>> DKC >>> >>> On 2012/7/1 21:13, m...@hurshtown.com wrote: >>> > In my 20 year experience of lagging down L feet on shingle roofs in >>> > Indiana with a good dollop of silicone caulk under the foot, I've never >>> > had an issue. No pre-drilling, just drive the lag home. Drilling a hole >>> > first is not necessary, and reduces holding strength. No reason to make >>> > a science project out of it and increase cost and labor. >>> > >>> > Mark >>> > >>> > -------- Original Message -------- >>> > Subject: Re: [RE-wrenches] L feet no flashing in shingle roof >>> > From: Drake <drake.chamber...@redwoodalliance.org >>> > <mailto:drake.chamber...@redwoodalliance.org<drake.chamber...@redwoodalliance.org> >>> >> >>> > Date: Fri, June 29, 2012 3:09 pm >>> > To: RE-wrenches <re-wrenches@lists.re-wrenches.org >>> > <mailto:re-wrenches@lists.re-wrenches.org<re-wrenches@lists.re-wrenches.org> >>> >> >>> > >>> > Hi Jay, >>> > >>> > There is no room for flashings. The L feet will go very close to the >>> > skylights and the flashing would hit the edge of them. Plus there is >>> > an existing array that was done by another installer that is done >>> > with L feet only. The new array would be higher. >>> > >>> > >>> >> And given that we have really good off the shelf approved flashed >>> >> feet, why would you use anything else? >>> >> >>> >> My 2 cents, >>> >> >>> >> Jay >>> >> >>> >> peltz power >>> >> >>> >> >>> >> On Jun 29, 2012, at 5:16 AM, Glenn Burt wrote: >>> >> >>> >>> We have used a variety of sealants over the years, and determined >>> >>> simple Henry roofing cement is the best product for use on comp >>> >>> roofing. >>> >>> >>> >>> We also used to bend our own L-foot flashing, which we cut from >>> >>> standard Al coil stock (before all the manufactured options were >>> >>> available). This might be a good option for you in this case. >>> >>> >>> >>> >>> >>> >>> >>> Glenn >>> >>> >>> >>> *From:* re-wrenches-boun...@lists.re-wrenches.org >>> >>> <mailto:re-wrenches-boun...@lists.re-wrenches.org<re-wrenches-boun...@lists.re-wrenches.org> >>> > >>> >>> [mailto:re-wrenches-boun...@lists.re-wrenches.org<re-wrenches-boun...@lists.re-wrenches.org>] >>> *On Behalf Of >>> >>> *Drake >>> >>> *Sent:* Thursday, June 28, 2012 6:40 PM >>> >>> *To:* RE-wrenches >>> >>> *Subject:* [RE-wrenches] L feet no flashing in shingle roof >>> >>> >>> >>> >>> I'm quoting a job that has an existing array with L feet bolted >>> >>> down to a shingle roof with no flashings. I want to match the >>> >>> height of the existing array. Also some modules are being worked >>> >>> in around skylights where it is unlikely that room would be >>> >>> available for flashings to center over rafters. >>> >>> >>> >>> I've always used flashings. Would it be completely crazy to >>> >>> follow suit of the existing array and bolt L feet straight to the >>> >>> shingle roof with good roof sealant? If so, how would you seal it? >>> > Drake Chamberlin >>> > ATHENS ELECTRIC LLC >>> > OH License 44810 >>> > CO license 3773 >>> > NABCEP Certified PV >>> > >>> ------------------------------------------------------------------------ >>> >>> > _______________________________________________ >>> > List sponsored by Home Power magazine >>> > >>> > List Address: RE-wrenches@lists.re-wrenches.org >>> > <mailto:RE-wrenches@lists.re-wrenches.org<RE-wrenches@lists.re-wrenches.org> >>> > >>> >>> > >>> > Options & 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 >>> > <http://www.re-wrenches.org/etiquette.htm> >>> > >>> > Check out participant bios: >>> > www.members.re-wrenches.org <http://www.members.re-wrenches.org> >>> >>> > >>> > >>> > >>> > _______________________________________________ >>> > List sponsored by Home Power magazine >>> > >>> > List Address: RE-wrenches@lists.re-wrenches.org >>> > >>> > Options& 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 >>> > >>> _______________________________________________ >>> List sponsored by Home Power magazine >>> >>> List Address: RE-wrenches@lists.re-wrenches.org >>> >>> Options & 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 >>> >>> >>> _______________________________________________ >>> List sponsored by Home Power magazine >>> >>> List Address: RE-wrenches@lists.re-wrenches.org >>> >>> Options & 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 >>> >>> >>> >> >> >> -- >> Bill Hoffer PE >> NABCEP Certified Solar PV Installer™ >> Sunergy Engineering Services PLLC >> 2504 Columbia Ave NW >> East Wenatchee WA 98802-3941 >> suneng...@gmail.com Cell:(509)679-6165 >> >> >> >> _______________________________________________ >> List sponsored by Home Power magazine >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Options & 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 >> >> >> > > > -- > Chris Mason > President, Comet Systems Ltd > www.cometenergysystems.com > Cell: 264.235.5670 > Skype: netconcepts > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & 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 > > > -- Bill Hoffer PE NABCEP Certified Solar PV Installer™ Sunergy Engineering Services PLLC 2504 Columbia Ave NW East Wenatchee WA 98802-3941 suneng...@gmail.com Cell:(509)679-6165
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