Has anyone built a pole building using "bookshelf construction method"?

[PoleBarnGuru]

Don't understand how skirt boards resist shear. They're 6" wide and usually have 2 nails per column. Shear walls need to be large panels to resist shear, like the prefab (usually steel) things they sell for use in California. Or are you talking about some other shear load?

The skirt (or splash) board is merely a portion of a shearwall assembly. A 2x6 with 2 nails at each end is not going to be adequate to carry anything other than the smallest shear loads (it would become the weak link of the assembly). The entire assembly includes the skirt board, wall girts, columns, end truss or rafters, any blocking between wall girts as well as the steel siding or other sheathing. Each member must be properly sized and adequately fastened to be able to transfer the loads.

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[BeezFun]

The skirt (or splash) board is merely a portion of a shearwall assembly. A 2x6 with 2 nails at each end is not going to be adequate to carry anything other than the smallest shear loads (it would become the weak link of the assembly). The entire assembly includes the skirt board, wall girts, columns, end truss or rafters, any blocking between wall girts as well as the steel siding or other sheathing. Each member must be properly sized and adequately fastened to be able to transfer the loads.

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I would say diagonal bracing is what resists shear. Agree that siding, girts, etc contribute something, but I wouldn't consider them a shearwall assembly, and without diagonal bracing it's going to be a leaning barn in 10 years. I consider the skirt board's function to keep dirt, wind and critters from coming under the sides, and in some cases keeping the concrete in when it's poured.

By the way, nice blog.

 

[PoleBarnGuru]

I would say diagonal bracing is what resists shear. Agree that siding, girts, etc contribute something, but I wouldn't consider them a shearwall assembly, and without diagonal bracing it's going to be a leaning barn in 10 years. I consider the skirt board's function to keep dirt, wind and critters from coming under the sides, and in some cases keeping the concrete in when it's poured.

By the way, nice blog.

Thank you very much for the compliment about the blog. I try to be entertaining and informative.

Diagonal bracing is great, in theory, until the numbers start being run in a structural analysis...then it turns out that unless the loads are very, very small, there is no way to get enough fasteners into the ends of the diagonal bracing.

We've actually laboratory tested a post frame shearwall with steel siding in a testing facility and got some pretty significant numbers - so we know it does work.

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[BeezFun]

Diagonal bracing is great, in theory, until the numbers start being run in a structural analysis...then it turns out that unless the loads are very, very small, there is no way to get enough fasteners into the ends of the diagonal bracing.

We've actually laboratory tested a post frame shearwall with steel siding in a testing facility and got some pretty significant numbers - so we know it does work.

Diagonal bracing is secured with fasteners primarily to prevent buckling, not to directly take the diagonal load. If it's done right it resists the compression loading from some structural element at the end, like a vertical column, and it's either blocked or let in so that it transfers the transverse loading to another secure element.

I'm surprised steel siding could result in anything acceptable as a shear wall. It's light guage, fastened with lightweight, non-structural short screws, and the corrugations result in direct shear failure unless they're rigidly fixed on both sides of the corrugation. I have access to structural analysis programs like Ansys, I could make a simple model to see how the wall on a pole barn behaves. Shear walls required by building codes, especially in earthquake zones, look like something designed to resist a direct hit from mortar. I'd be interested in seeing some of the results you got from the test facility, in particular what girts, fasteners, and siding screws were used.

 

[Duffster]

From experience, properly constructed, there is no reason you would ever experience any challenges with columns embedded into the ground.

Maybe you could expalin then how frost doesn't lift on the grade board?

 

[Duffster]

Steel brackets fabricated at a welding shop will not meet the requirements of the building codes.

The one we use pass. Besides not all buildings have to pass.

 

[BeezFun]

Maybe you could expalin then how frost doesn't lift on the grade board?

I already decided to do something different for a skirt board. There's really no reason to attach it to the columns once it's backfilled on both sides. I also can get heavy flexible rubber like they use for stall mats. There's a quarry nearby and they sell their conveyor material once it's worn out. It would be perfect for this because it's tough but flexible and nothing will eat through it.

 

[BeezFun]

The one we use pass. Besides not all buildings have to pass.

Yes, I'm exempt from building codes for agricultural buildings. True in many rural areas.

 

[jimgerken]

Yes, I'm exempt from building codes for agricultural buildings. True in many rural areas.

Regardless, the weak link is going to be the post. I don't care what the steel is made of, or how it is fastened (within the two choices of wet set or drilled expanding anchor bolt) the post will split and break off before the anchors or bolts pull or the bracket straightens out. It takes way less than I would have guessed, before experienceing it happen twice one day, to pull a 6x6 post in two. Certainly once you concentrate all the force of two 1/2" bolts drilled thru the post you have "drawn a dotted line" thru that post right there.

 

[Duffster]

Regardless, the weak link is going to be the post. I don't care what the steel is made of, or how it is fastened (within the two choices of wet set or drilled expanding anchor bolt) the post will split and break off before the anchors or bolts pull or the bracket straightens out. It takes way less than I would have guessed, before experienceing it happen twice one day, to pull a 6x6 post in two. Certainly once you concentrate all the force of two 1/2" bolts drilled thru the post you have "drawn a dotted line" thru that post right there.

What is going to have that much uplift? a tornado? It won't matter then.

The way we do it the sill board/plate/girt (whatever you want to call it) is bolted down as well with all of the side steel screwed to the sill plate so any uplift is spread across more then just the 2 bolts.