Building Workshop 30X48

I live in New Jersey and have not broken ground yet but will need a cutter or two before July

I have a flat ground and will put in the slab soon. I have a new 236 Hudson mill and the lumber is basically procured. I have a nice home with a bed and bath and need about a months worth of labor. Cut, join and SIPs.

I need to have some advice on my 30x 48 workshop. I need to have the barn free and clear of posts. Four bents but no post in the middle two bents of the frame. Is it possible to have a large beam without a truss or post with a dovetail mortice joint?

Can someone give me advice on footings for a monolithic slab for my 30 x48 barn. Each end is 4 posts and 2 on each on the side. I am the owner and can sign off on my project. That said I would like to get some engineering advice cash or free no stamp needed.

Why do you want to avoid a truss? Spanning 30 feet with a single beam is unreasonable. A truss would give you a set of rafters which would carry the load of bays into the wall post, via purlins. You would not have as big a load on the top plates. And greatly reduce the thrust of common rafters. Use a english tying joint at the tie, post, top plate connection.

55 gallon drums set into the ground at the post locations, and form your slab on top of 'em. Perhaps doing this you may avoid the monolithic slab formation. Unless it is needed for other reasons than supporting the wall system. Are you heating the shop space?

I was going to put radiant heat in the floor.

Tim appreciate your help. If I use 12X12 posts how large in dimension would I need for the tie beam and would I do king post truss? What type of dimension would those particular rafters be and the truss need to be that ties into the Tie beam? What type of joint would I use for truss to tie beam or maybe use steel plates?

Thanks
Jim

Check this out, good evening reading. I am most familiar with Fig. 1-3 but have diddled with some of the others. Pay attention to the building sizes and timber used. I suspect if engineered today the timber sizes would be increased some what.
http://www.tfguild.org/joinery/part2.pdf

To answer your question in any reasonable sense goes beyond reasonable guise of the forum. And so your education begins.....

As for post sizes 12" x12 " post may be over sized, but I do not have all the facts. I have a 30'x60' clear span, king post building, w/ 16' tall post. They are all hard wood of various species. They are fan tailed posts, meaning they taper from the bottom to the top(see link provided) most are 7x9 at the bottom to 7x12+ at the top. This was built about 10-14 years ago. Today they would all be 9"x 9" at the foot and 9"x14" at the tops. The change is due to learning as you go. It is not a structural issue but more a joinery driven change.

The tie beams are 7"x 9"x 30', there are no joist cut into them. I have lodged joist on top of some for minimal storage in the truss roof system.

Rafters similar size but have 2x's let into the faces for purlins.

Joint for the king to tie connections...... No need for plates. I can't link it but it is found here. Historic American Roof Trusses A extra long through tenon with a wedge on the under side of the tie beam, for a dutch flavor, would be on such connection possibility, pegs in the face as well.
http://tfguild.org/pubpg.html

You live in an area where your could easily find an engineer schooled in timber framing to assist in proper sizing of your post and beams. Search the Guild site for a list of engineers.

And greatly reduce the thrust of common rafters. Use a english tying joint at the tie, post, top plate connection.