Am sure yesterday’s blog posting on moments left a few folks scratching their heads. There actually was a method to my madness, as it leads into today’s topic.
Many may have seen various column bases at their local lumberyard or big box store. Manufactured by either Simpson or USP (similar to Simpson CB66), these products have some serious, and perhaps fatal consequences if used to support posts in a pole building.
These bases are not designed to resist overturning (moment) loads. Now this poses a challenge – how to connect post frame building columns, to a concrete foundation?
There is a solution…..
Sturdi-Wall concrete brackets are a heavy duty anchor system designed to connect post frame structures to traditional concrete foundations such as: monolithic slabs, formed walls, and existing concrete pads.
There are two types of Sturdi-Wall concrete brackets. When drill setting is preferred, the standard Sturdi-Wall is used. When setting into wet concrete, the Sturdi-Wall Plus is used.
One challenge, not directly mentioned by the product manufacturer, is the standard Sturdi-Wall concrete bracket is not designed for moment loads. Post frame buildings want to overturn; they do induce moment loads, which leads me to discourage people from using the standard bracket for this application.
Wet set installation with Sturdi-Wall Plus brackets provides the highest ultimate strength connection to a foundation, but requires being installed while the concrete is still wet. This technique avoids time consuming drilling with a masonry bit and expensive concrete anchors. Sturdi-Wall Plus concrete brackets require less concrete coverage than normal Sturdi-Walls, allowing them to work well in pier foundations.
A pier foundation would be one where isolated holes are augered or dug, then poured full of concrete.
For cases where, for whatever reason, it is desired to NOT place pressure preservative columns into the ground to support a pole building, the Sturdi-Wall Plus concrete bracket provides an solution which is capable of resisting uplift, shear and moment forces.
See, it was worth struggling through yesterdays’ blog on “bending moment” to make you “in the know” for today!
Nice! But I need 4×4 brackets for my garden gate posts. Any ideas?
Tony – For a simple garden gate project they make some light gauge steel U Brackets that can be concreted in or fastened to concrete that would work well. Stick with a galvanized product to prevent rust. I would recommend the Simpson Z-Max 4×4 post base for such a project found online/at The Home Depot. https://www.homedepot.com/p/Simpson-Strong-Tie-Z-Max-4×4-Standoff-Post-Base-ABA44Z/100374999#BVRRWidgetID
Wow. Good stuff.
Let me ask you, in the article you say that sturdi wall plus brackets can be used in concrete piers. I am considering using them in sonotube piers to build a two story shop building (24×32). Do you have any suggestions about depth and diameter of piers, and post spacing with this arrangement? The info on their website is simply too skinny.
Thank you very much for your kind words.
Typically columns on a 32′ wall would be spaced 10′-12′- 10′ and endwalls every 12′, of course with appropriate variations for door locations. In order to determine depth and diameters, it would take a complete engineering analysis of your buildings as dead loads, wind speed and exposure and soil bearing capacity all need to be appropriately factored in. If you are ordering a Hansen Pole Building, then all of these are accounted for after your order has been placed.
I am going To put up a patio roof structure I need concrete brackets for posts that are being made from hundred year old barn beams they are 7 to 8 in.² where do I find brackets for that.
We source brackets for Perma-Column. I would suggest contacting the Pro Desk at your local Home Depot or lumberyard to check availability in your area. I would also advise using a registered design professional to confirm the posts and other materials will meet your local design criteria.
Do you have brackets for a 12×12 column.
The largest available bracket is for an 8 x 8 column. You may need to have your engineer design a bracket and have it welded up to meet his or her specifications.
Where can I obtain info on purchasing about (twenty) 8 inch by 8 inch heavy duty anchors to connect post frame structures prior to pouring my garage floor?
Please contact Materials@HansenPoleBuildings.com and include your ship to address.
What about Simpson Strongtie MPBZ bases? Would using these or the Sturdi-wall bases eliminate the need for knee bracing?
Brackets for post bases will have nothing to do with knee braces. Knee braces can (and should) be eliminated by utilization of the steel skin. https://www.hansenpolebuildings.com/2019/03/fight-knee-braces/
Wouldn’t that only be the case for diaphragm buildings? For non-diaphragm buildings (structures without girts and siding), knee braces and wye- or x-bracing are used to prevent the post from twisting.
Roof only (non-diaphragm) buildings should have columns designed as cantilevers. Knee braces are generally highly ineffectual (https://www.hansenpolebuildings.com/2012/01/post-frame-construction-knee-braces/) and Y or X bracing is unlikely to prevent a column from twisting.
The install of my pole barn talked me into the Sturdi-Wall concrete bracket not the plus, now i know they are not as good after reading your blog. my question he is putting a 5.5 slab with fiber mesh and wire is that good enough or is a footer needed it is a 44×24 pole barn enclosed.
There should be a concrete pier under each bracket, edge of slab should be thickened, or have a continuous footing. Reach out to the engineer who sealed your building plans as to his or her recommendations (it should have been called out for on the sealed plans).
We install the bolt down brackets on foundation walls with absolutely no issues. We have taken a 18’ post that’s bolted to the bracket and pulled the top of the post over to see if the bolts would shear off the foundation. Post snapped 3 feet above the bracket. Bolts were still tight fastened against the wall. Whoever is telling people those brackets are not good enough doesn’t work in the field everyday. Here in Illinois, many folks have seen post sucked out of the ground. Brackets all day people and don’t listen to this geriatric who posted this “research”.
The bolt down (dry set) brackets specifically state (by the manufacturer) they are not designed for moment (bending) loads. Wet set brackets are an entirely different story, as they will resist bending loads (provided they have an ICC ESR approval).
6×6 treated wood column:
what is the bending moment value when using a sturdi wall plus wet set bracket vs the column set in concrete below grade?
how much more resistant to moment is the column set below grade?
Moment forces on a bracket set column, as opposed to a properly constrained embedded column (https://www.hansenpolebuildings.com/2018/11/importance-of-constrained-posts/) are 1/3rd greater