Saving rotted off poles, pole barn

[zkdiesel]

What are you guys using to save rotted off
Posts? Buildings been rettined once but now poles all shot

Poles
Measure a true 6”. Anybody have a solution other than our home brew idea that we are going to try?
Plan is to sleeve them in 20” metal at the base, weld rebar sticking out 3 directions to each once, through bolt metal through upper part of good wood, then Pour concrete slab trapping the rebar and the sleeve in concrete to retain it

Barely anything holding it up at this point at the 50 year mark and it hasn’t fallen down in the microburst we had this spring, so this should be a big upgrade

 

[Firebrick43]

Around here they dig down aside the post(typically the out side) support the header with jacks on either side, cut the post off above ground level with a sawzall lifting with the jacks as they do slightly, and slide/tilt a permacolumn into place and drill/bolt it fast to the portion of the original post. I have seen some guys that worked together well could do a building in a day. They use a mini excavator to dig and pull old post/lower new ones into place.

Some do every other post and fill the holes with concrete, some tamp dirt around the new post. In this area it’s mostly clay so there is not much dirt collapsing into the hole if the excavator operator is good. In sandy areas up north some have a slab jacking company come in and use lime slurry under the slab near the post to deal with dirt collapsing from under the slab.

How are you getting the sleeve around the existing post? Only 20” down? A pole building relies on the post set 4’+ for shear strength. Also it considered to be a bad idea to couple the slab to the post especially in area that freeze and thaw and building that are not heated full time as it leads to frost jacking.

 

[DennisK]

we did one about 7-8 years ago, The owner found precast anchors for 6x6x4ft post. jacked up w/screw house screw jacks about 6ft apart, dug 1 ata time, set precast and back filled w/coarse rock. Slicker than u know!

 

[jeepinerdeep]

A while back, Tractor Time with Tim had a YouTube video of bringing in a contractor that drove sleeves around the poles with a pile driver on a skid steer. Looked like specially formed galvanized guard rail. That fella is a bit of a goober, but well meaning.

 

[Jeepster04]

How are you getting the sleeve around the existing post? Only 20” down? A pole building relies on the post set 4’+ for shear strength. Also it considered to be a bad idea to couple the slab to the post especially in area that freeze and thaw and building that are not heated full time as it leads to frost jacking.

I dont believe shear is an issue near the groundline. Bending moments and tension (uplift) would be the reason you need the post 4' in the ground.

 

[Fcvapor05]

I dont believe shear is an issue near the groundline. Bending moments and tension (uplift) would be the reason you need the post 4' in the ground.

You need deep posts to resist soil shear from moisture changes and heating/cooling, which will rack the entire building.

If you sleeve a rotted post, it's going to keep rotting and it's going to do it much faster because all the moisture will be trapped inside your sleeve. The sleeve will corrode as well, which eventually is going to crack the concrete and spall off the surface near the posts. When you go to fix that you're going to have to chip out all the concrete around the posts to remove the rotted wood and install proper post bases.

Cutting them at the top of the slab and then using post anchors now is going to be by far the most durable solution.

 

[Firebrick43]

I dont believe shear is an issue near the groundline. Bending moments and tension (uplift) would be the reason you need the post 4' in the ground.

Shear forces of the building as a whole are transferred to the pole(yes as bending moment) in a pole building. They traditionally don’t include a strong diaphragm such as osb/ply sheathing on the roof deck and walls. Instead use a light diaphragm(buildings tin) and the poles themself to save material and therefore money. As a result you can’t just wack off the poles and attach them to a slab; which solves only the uplift portion of the problem.

 

[zippyslug31]

Hearing stories like this makes me glad I paid the extra $ to have permacolums as part of my build a few years ago. I suppose that even with full wood poles the barn will live longer than me, but still... no future owner should have to worry about it which should help with my future resale value.

 

[NUTTSGT]

A while back, Tractor Time with Tim had a YouTube video of bringing in a contractor that drove sleeves around the poles with a pile driver on a skid steer. Looked like specially formed galvanized guard rail. That fella is a bit of a goober, but well meaning.

I watched that video, it was quite interesting.

Found it.

 

[nadogail]

The steel sleeves have saved many posts.

 

[zkdiesel]

Building saved

 

[TractorJeff]

Nice Pour!
At least pouring concrete inside a double door building would be cooler than outside in the hot weather We have had lately

 

[mustangcrazy77]

Shear forces of the building as a whole are transferred to the pole(yes as bending moment) in a pole building. They traditionally don’t include a strong diaphragm such as osb/ply sheathing on the roof deck and walls. Instead use a light diaphragm(buildings tin) and the poles themself to save material and therefore money. As a result you can’t just wack off the poles and attach them to a slab; which solves only the uplift portion of the problem.

You can if you use wet set brackets that have are engineered to resist a moment. I believe Simpson makes one or two.

 

[NUTTSGT]

Building saved

That will last your lifetime or atleast to the age where you no longer care.

 

[zkdiesel]

Yep. Next building

 

[zkdiesel]

Getting doors to work

 

[Firebrick43]

You can if you use wet set brackets that have are engineered to resist a moment. I believe Simpson makes one or two.

https://www.permacolumn.com/downloads/327/sturdi_wall_design_and_use_guide_2020_with_calculations.pdf

Again, they are meant for loads that the poles are not bending, see bottom of page 4.

“ wood columns need direct bearing on the bottom to transfer axial loads directly into the concrete foundation. The Sturdi-Wall brackets are assumed to have no moment capacity. The building must be designed to resist lateral loads through diaphragm action or other bracing means.”

So you can NOT just install these brackets as a replacement for rotted post. You MUST retrofit a full diaphragm or significant diagonal bracing if you use this method. With permacolumns no changes are necessary. Just dig out the old in ground portion and replace with the concrete post/bracket unit and backfill

 

[mustangcrazy77]

https://www.permacolumn.com/downloads/327/sturdi_wall_design_and_use_guide_2020_with_calculations.pdf

Again, they are meant for loads that the poles are not bending, see bottom of page 4.

“ wood columns need direct bearing on the bottom to transfer axial loads directly into the concrete foundation. The Sturdi-Wall brackets are assumed to have no moment capacity. The building must be designed to resist lateral loads through diaphragm action or other bracing means.”

So you can NOT just install these brackets as a replacement for rotted post. You MUST retrofit a full diaphragm or significant diagonal bracing if you use this method. With permacolumns no changes are necessary. Just dig out the old in ground portion and replace with the concrete post/bracket unit and backfill

You are mistaken on a few different points.

The brackets that have moment capabilities are the permacolumn sturdy wall plus. You can see the design manual here.... https://www.permacolumnnw.com/downloads/pdf/Sturdi-Wall Plus Design Maunal 2-22-07.pdf

Notice that these DO have moment capacity.

The second part you are mistaken on is that even permacolumns require diaphragm action to resist lateral loads in the weak direction. Notice the assumptions they use before drawing a FBD for calculations...

"Full lateral bracing and major axis bending only; no loads acting on weak axis; no knee-braces; no splices in laminated wood portion of Perma-Column assembly"

For both the perm column and the sturdy-wall plus brackets, weak axis bending is assumed to be resisted by diaphragm action via the roof. Luckily, most typical pole barns with purlins and properly screwed ag panels will give you this.

So yes, you can install these brackets as a replacement for rotted posts....assuming you meet the design requirements (concrete PSI, soil bearing etc.) listed in the design manual.

 

[Firebrick43]

Thank you Mustang for showing that. I stand corrected that there is indeed wet set brackets that will work for moment loads.

The few that I have been exposed to are not and I guess my “***”umption made me one.

I guess the take away for everyone else is make sure what your buying can take moment loads by the technical docs. Similar appearances doesn’t mean similar performance.

 

[mustangcrazy77]

Thank you Mustang for showing that. I stand corrected that there is indeed wet set brackets that will work for moment loads.

The few that I have been exposed to are not and I guess my “***”umption made me one.

I guess the take away for everyone else is make sure what your buying can take moment loads by the technical docs. Similar appearances doesn’t mean similar performance.

Hey, I once thought the same. It's tough to keep up with some of this stuff when you're not working with them or going to trade shows.

With that said, you're right about the takeaway. I'll add to that, anyone that doesn't understand what a free body diagram is or a moment...you're best bet is to talk to the manufacturer first. Many licensed/bonded contractors don't know this stuff...and I'm not aware of many other brackets out there that have been designed and are certified to take moment loads.