DIY trusses?

jklingel

Has anyone run any of the readily available residential truss design software? I am just wondering if any of the programs require less than an engineer's or architects training to operate them. I have no idea what info they require one to enter. I've got a double-Howe, 4:12 pitch, drawn up in my CAD program, and it looks like such a truss is a pretty simple object. However, I am not naive enough to think a truss is simply a matter of Xeroxing what you see in literature. Though I have very few joints and I THINK 2x6 is big enough for top and bottom chords, I'd like to have that, and other questions, verified. I know I could hire an engineer or truss shop, but then I won't be learning much. My clear span is 39', with 4' beyond the 2x6 wall the truss sits on, so I will have some cantilever activity to compound things. Too, the truss needs to be 34" high when it hits the bearing wall, so it will have an energy heel boot. I don't need to program to explain which non-chord members are in compression/tension and what any moments on them are, I just need to know if what I have will support 80 psf, etc. If software is out of the question, how about books I could buy and run my own numbers? I'm not an engineer, obviously, but numbers are my friends. Thanks for any info. john

joecaption

Whole lot of work and time for something you may not even be able to use.
May want to spend your time designing the layout.
No idea what your local area requires but I'd never get away with DIY trusses or my own design on something like this.

titanoman

Me neither. I leave that to the guys that build them every day. Plus they're is somebody besides yourself that must answer to a failure.

Gary in WA

Not really. I have a few sites on gussets. pp. 178: http://books.google.com/books?id=bwt...page&q&f=false

http://docs.google.com/viewer?a=v&q=...6fTirapfPwoKzA

Sorry.

Gary

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jklingel

Thanks for the opinions and info. We built the trusses for my present house (27' clear span) and garage in '80 and '75; no code requirements, etc. I had an engineer design the house trusses, and my dad and I just built trusses from our heads (mostly his) for the garage. (Those were real simple though; 30' span w/ a beam in the middle.) I'll keep poking around, as I really think it is doable. Yes, there is a lot of time in building trusses; no doubt about it. But, constructed ones are about $300 each and the materials are about $150. As this would be my day job, any money I make will be after taxes and not too shabby. Once you get the first one figured out (we did it by T&E on the house), you can mass-produce the boards fairly quickly..... if you like monotony.... Besides, I know those PA plates they stamp onto the trusses work, but they look rather wimpy.

titanoman

Have you ever tried to rip a PA plate off? They're there for good.
But you're right in the sense that plywood gussets are just as good, and I would build my own trusses for my own house (at least the simple ones).

Daniel Holzman

You seem to be suggesting that you plan to build trusses for sale to the public. At least I think that is what you are saying, based on the comment about making money after taxes, this would be your day job etc. You may be able to build your own trusses for your own use, especially if you live in a county with no building code, and/or no enforcement. To build trusses commercially is a whole other kettle of fish, you would almost certainly be violating multiple statutes to do that, as you are not a licensed engineer, and you probably lack the standard equipment (specialized air gun) to put on the gusset plates, meaning you would have to design and install plywood gussets.

I hope you are not suggesting you want to go into business building home made trusses for sale to the public. That would be a truly bad idea.

jklingel

Sorry about the confusing statements. I would be making money solely by saving money, hence the phrase "after taxes". People sometimes forget that to pay Bubba $20 you have to earn $2X. I am retired, so my time is cheaper than when I worked for The (Wo)Man, and I am more interested in learning stuff "cheap" (buy software, read books) for that reason, and I usually only want a thin sliver of the knowledge base. Yes, building a plant, getting licensed, let alone spending years learning what I'd need to know, is a whole different world. For a couple of reasons, I have no interest in another REAL day job. Now, as an engineer, do you think it is even reasonable for a DIY-cat to utilize software for truss designing? (I've posed that to a couple of software co's, but have not heard back yet.) As I said above, if the program is going to ask for nitty-gritties, I'm toast. thanks. j PS: All that said, I would still take the finished product to an engineer for verification. I mean, does this face look stupid? ----> PS: I just got an email from one of the software companies. In short, forget it. You really need to have engineering knowledge to operate the software. P, EOS. Scratch that one off the list.