The Forestry Forum

I'd like to get some suggestions for truss design for a shop I am planning.

I'd like the width to be 24' to 26' without any support posts.  But, I'd also like attic storage...nothing heavy (<2 psf).  I've looked at a King Post design using a 12/12 slope, but I think the struts would be too intrusive to be used for storage.  I'm reading up on Queen posts as they seem promising.

Should I give up on the storage and 'show-off' the King post/struts?

Thanks.

  I don't think simple queen posts will work in this application as they work in compression (propping up the roof) and do nothing to support the attic floor.  My engineer's barn has a very cool canted queen/scissors arrangement which allows clear span on the first floor and enough load bearing capacity on the second floor for his workshop.  I wish I'd got a couple pictures before they enclosed it.

  The king post works in tension holding up your spanning beam and giving your attic floor the support it needs.  As a majority of attic floor space is between the king posts the actual space loss isn't too excessive.

You can review the pictures of king post trusses at Fox Maple in the thread about king post, and Fox Maple pictures in my gallery.
You might need to have a king post truss with small queens as well.
Any design should be built for future use as well as current use. If you sell the property will the new owners know that the floor load rating is only 2 psf?
You maybe should build it to standard loads now, the right way or no load at all, and forget the attic storage idea......

Jim Rogers

The Fox Maple barn looks like a real nice project.  It is similar to the Hall School Storage Barn described/built by Sobon and Martin in 'Timberframe Construction'.  This was sort of my inspiration.  It looks like the FM barn has two-piece tie beams, which would work better for me as I can only saw 20' on my bandmill.  It seems a bit wider, too.  Can you remember the dimensions?  Are these plans available anywhere?

You make a good point regarding the attic storage...do it right or make some pretty trusses enjoyed from the floor.

Thanks.

Quote from: stilloggin on November 09, 2006, 09:41:34 PM
It looks like the FM barn has two-piece tie beams, which would work better for me as I can only saw 20' on my bandmill. 

I am currently constructing a shed with splined tie beams.  Look at the thread on "tractor shed" and the thread on "king posts".  Personally I would be Leary to use a two piece tie beam if you are going to have any additional loads in the attic.  Then again the only way to know is do the engineering.
I would not let your band mill bed length be the limiting factor.  I have not done it yet but you can cut longer than you band mill bed by sliding the log down and making a second cut.  Do a search on the entire forum, you will find several posts on the subject.  Could be fun to try ;)
max