Saltbox Question on Roof Truss

Started by MichaelM, February 09, 2008, 03:05:23 PM

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MichaelM

Howdy,
I've been taking my first close look at the roof truss design.  It seems real easy to work with (small - only 12ft long, simple, lightweight). 

My question: Can I fabricate these myself, rather than a truss manufacturer?

I have no experience in housebuilding, but the design seems pretty easy.

Thanks, michael

MountainDon

Generally speaking self built trusses will not make it through any permitting or planning department. If you need approvals to build trusses need an engineers stamp to be included in your project. The alternative is to use regular old rafters.

However, if rules and regs are not in place or to be ignored  Shocked there is information available for self built trusses. A quick side note; those metal plates you see used in commercially produced engineered trusses can not be installed by hammering them in place. Truss manufacturers us large presses and thousands of pounds of pressure.

The University of Missouri, has information on glued wood trusses

These use plywood gussets in place of metal plates. They are glued and nailed. Waterproof glue recommended. The designs do not meet current code and are sold with a disclaimer to that effect. There are a great number of farm buildings that are decades old still standing today tho' as well as a garage I built a long while back.


You mentioned a 12 ft... rafters aren't all that difficult for that size
Just because something has been done and has not failed, doesn't mean it is good design.


John Raabe

When I built the solar saltbox the inspector OK'd the site built trusses since the rafters alone would have met the span requirements. We built them on the deck and lifted them into place. They are overbuilt but make for a strong attic.

But, especially for longer span trusses, the truss company engineering is needed in many jurisdictions.
None of us are as smart as all of us.

MichaelM

Alrighty, it sounds like I can make my own trusses (as long as building dept. is ok with it).

So if metal plates can't be hammered on, and wood plates (as in plan) are not allowed by codes......I wonder what options I have for making my own?

Any ideas?

michael

MountainDon

That's what your discussion with the bldg. dept. will resolve.

See if they will go for plywood gussets, 3/8 or 1/2 thick , nailed and glued, both side of any joints.

If they will I'd suggest that book previously mentioned as it does have lots of design info. (copyrighted publication) Or maybe they'd have info you could use, or suggestions
Just because something has been done and has not failed, doesn't mean it is good design.