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40'x40' mezzanine / loft in my shop

ercrwe's picture

I have an extremely small project that is probably a waste of of an engineers or architects time but maybe someone here can refer me to someone or someplace with my info. I have a small shop that I want to add a good size loft or mezzanine. The shop is a free spanning 40x40x25’ tall, and I would like to build a loft that maintains the same free spanning design down stairs. I am unsure what the best way to approach this to have a load minimum of 50psf uniform, and a concentrate of 1000psf. The upstairs will just be for storage and office space so we want to design the floor to be easy to install and inexpensive material wise. I am tryng to pull my permits but they need to know about every nut and bolt and how far apart they are spaced first. I want to use steel beams that can make that 40’ span by 40' long. I plan to use plywood for the top sheeting followed by carpet and maybe some tile. So design ideas other people have offered up were to run heavier duty length wise on either end of the shop followed by smaller beams width wise reting on the 1st beams then to use this lighter gauge steel stamp in a sort of U shape that runs back the opposite direction of those beams to attached the plywood to. I am not sure of the terminology. Another person said I should run a 3rd heavy beam length wise down the middle of the shop which would be free spanning but allow the beams I place on top to only need to be 20' wide so they would not need to be as heavy duty as beams that span the entire 40' width of the shop. I really don't care how it is constructed just as long as it is the best use of my money and can meet the code requirements without bouncing as you walk across the floor. I was considering making the floor 2000psf concentrate just to give extra support but IDK if that means doubling the cost of materials for no particular reason besides a "just in case" sort of thing. I wish there was some sort of program I could find that could figure out my load requirements and help with my design. Ifthere are any engineers out here that want a small side job please let me know. I assume for anyone that does this for a living my jobs is almost so small it's not worth a professionals time, but I figured I would try to leave a post here and see if I get lucky. Thanks in advance for any real help someone has to offer.

Be aware. (post #215891, reply #1 of 5)

As soon as you talk steel beam, you are in need of engineering.

As soon as you talk 40' span you are in need of engineering. 

As soon as you talk storage you are no longer talking about a 50# uniform load. 

As soon as you talk second story, you are talking about latteral loads and engineering. 

1600 sq. ft. is by no means an "extremely small project". This is not a small engineering "side job".

well aware and the whole reason I am asking for help (post #215891, reply #3 of 5)

You were so quick to jump to the conclusion I was trying to do something wrong you clearly didn't read my whole post where I specifically asked if there was an engineer that saw my post who was willing to take on my project for hire even though it wasn't an entire building design project.

well aware and the whole reason I am asking for help (post #215891, reply #2 of 5)

You were so quick to jump to the conclusion I was trying to do something wrong you clearly didn't read my whole post where I specifically asked if there was an engineer that saw my post who was willing to take on my project for hire even though it wasn't an entire building design project.

If you learned what a (post #215891, reply #4 of 5)

If you learned what a "paragraph" is then people would be more likely to read your entire post.


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

This is a BIG project. (post #215891, reply #5 of 5)

My point was that this IS essentially an entire building design project. It will involve footing design, gravity load design and most significantly lateral load design. It involves modifications to your existing building as well as new construction. An engineer is going to have to stamp the plans which puts his butt and insurance on the line. As I see it this is a bigger project than the building itself was. It wouldn't supprise me if it costs more to build than the shop did. 

I read your post well enough to see that you considered this an "extremely small project" and a "small side job". It is neither.