Need Help with Pole Barn Loft Design

[Enracer]

Hello all,

Just joined the forum and looking for some advice on a loft I'm building in my equestrian pole barn. The interior of the barn is 40' x 60', and it will be an end-loft extending out 24' from the back wall and spanning the entire 40' width. I'm planning for a live load of 50 psf, which I think just about maxes out the 2x12s across the 16ft center span. Page 1 of the attached pdf has a floor plan with the barn and loft dimensions and the locations of the interior posts.

My question pertains to the yellow header beams on page 1, which will support a 12' joist to the side wall on one side and a 16' joist across the center aisle on the other. I'm planning to make glulam beams with 2x12s and 1/2" plywood, but I'm not sure of the best/proper method of connecting them to the posts. Can I use this Simpson Strong Tie, or should I add two additional 2x12s and through-bolt the beam through the post...or a combination of the two...or something else entirely? I will not be able to recess the beams into the posts. Page 2 of the pdf shows my proposed glulam beam design and attachment options.

The headers at the side wall will be doubled 2X12s, and all joists will be 2x12s and attached with joist hangers.

Please let me know what you think.

Thanks!!

 

[aczlan]

I would ask your local lumberyard for a quote on prebuilt laminated beams. They can do the calculations and provide a stamped drawing if needed.

Aaron Z

 

[Enracer]

I converted the pdf into two jpg images. Hopefully these will work better if anyone is having issues downloading or opening the pdf.

 

[Woody65]

I believe either method you put forth will be sufficient. The only thing I would add is a 2x6 under each beam that is attached to the post and extending to the floor to act as a shelf. It's nice to have the beam resting on something to carry a direct load to the post and floor. If this is not possible because of something in the way, a 6x6 brace at a 45 degree angle from the post to the beam at each connection would do. Good luck with the project.

 

[s219]

Howdy neighbor! I live down off Forge Rd in Toano.

I echo the previous post suggesting you price up LVL beams, as they will be stronger and lighter than the laminate you propose, and may open up some additional options for brackets to tie them to the posts. When making a glue-lam at home, you really don't get any trustworthy benefit beyond the additive stiffness of the multiple elements as if they were just bolted or sistered with lots of nails. Your home-grown gluing process is not something that can be rated or tested. A commercial glue-lam ends up having better "certified" properties in a thinner beam, and may even come out close in cost.

The real answer to your question about bolting through or using hangers really depends on the lumber and the bolts. A wood structural design handbook will give you numbers for the wood grain's ability to bear and handle fasteners without the grain compressing or shearing/splitting. You can avoid that whole calculation with the simpson hangers, which use lots of smaller fasteners to spread the load so that you're putting much lower stress on the grain. Simpson hangers are also designed to optimize nailing patterns into the grain to avoid shear situations and to cross the grain strategically. As long as the simpson numbers match your load needs, you're good to go. Simpson has very detailed specs on their website that you can trust. Be sure to get hangers with the special galvanized coating if your posts are pressure treated, as standard simpson hangers (although galvanized) are not rated for pressure treated wood. I believe they add a "Z" to the model number of products that are rated for treated wood.

Aside from bolts or hangers -- if you can't notch the posts, I really like to have beams sitting on something, whether it's a bracket or even sistered boards or a sistered beam. For instance, nail a 2x6, or two of them, to the face of the post and that gives you a nice little shelf to rest the beam on, then you can use simple gusset plates to keep the beam in place. The 2x6 would be nailed with lots of smaller nails and resting on the floor, so again you get that benefit of spreading things over a big area in terms of bearing on the grain. (I see Woody65 already suggested that).

 

[TSO]

Here's what my uncle did with his 40x60 he just built... I believe the loft is 16' x 40' plus the 16'x12' landing. He has since finished it but i haven't been over I'm a couple weeks, I'll grab updated pics when i go back.

.

 

[teg]

Here's what my uncle did with....

Is that a potato gun? (sorry for sidetracking )

View attachment 498762

 

[TSO]

No, of course not, we just use it for launching tennis balls for the dogs

 

[Enracer]

Is that a potato gun? (sorry for sidetracking )

View attachment 498762

I need to get one of those added to my plans!!

So after some more deliberation, I think I'm going with option 1: the 5 1/2" glulam beam supported by a Simpson HUCQ612-SDS heavy duty joist hanger.

The hanger is rated for a 5,315lb floor load. If my math is correct (which admittedly is a bit optimistic), that should be sufficient: each glulam beam supports approximately (6'+8')x12'=168sqft of loft. At 60psf loading (50psf live and 10psf dead), that's 168x60=10,080lbs on each beam. With a Simpson hanger at each end of the beam, each hanger must support 5,040lbs...which is less than the 5,315lbs its rated for. Plus, I'll likely add a separate brace beneath the Simpson hanger that's through-bolted to the post...just for good measure.

I've also included a more detailed floorplan of the loft.

Thoughts?

 

[Travelover]

I'm a mechanical engineer, though I spent my career designing trucks. If I was doing it, I'd use the hanger and I'd also bolt a 2x6 parallel to the post under each joist to act as a shelf, as others have mentioned. The hanger keeps the joist in position and the 2x6 acts as a backup if the hanger rusts or fails.