Tag Archives: embedded columns

Full Foundation, Hurricane Proof, and Drill-Set Brackets on Slab

This Wednesday the Pole Barn Guru answers reader questions about a village or township requiring you to put a full foundation in for a pole building, whether a pole building is “hurricane proof,” and the potential use of drill-set brackets to set 6×6 columns on an existing slab with thickened edge.

DEAR POLE BARN GURU: Can a village or township require you to put a full foundation in for a pole building? CHRISSY in CHANNAHON

DEAR CHRISSY: Our country has two model Building Codes – IRC (International Residential Code) for one and two family dwellings and their accessory structures, and IBC (International Building Code) for all other buildings. Neither code has a requirement for full foundation to support pole (post frame) buildings. I would encourage you to reach out to your local Building Official to ask for further information – it is possible your village or township may have enacted a specific ordinance, to this case, if so – request a written copy of the approved document and please forward it to me for review. In most instances, no such ordinance exists and, if so, this ‘requirement’ cannot be legally enforced.



DEAR LINDA: I don’t know of any structural system other than maybe a reinforced concrete building underground and above any flood stage affording 100% hurricane protection. We can engineer to design wind speeds in excess of 200mph.


DEAR POLE BARN GURU: I have a new monoslab with 20″ footer all around. Slab is also reinforced with 1/2″ rebar. I want to build a 40’x46′ pole barn. Walls are 14′, roof trusses are 5/12 pitch. Can I use Simpson brackets and place 6″x6″ posts on top of the concrete every 8′ with 2″x6″ girts? Or should I have builder put posts in the ground around the slab? Thanks-ERIC in REXFORD

DEAR ERIC: There is no dry set (bolted down) anchor (including those from Simpson) capable of handling even minimal moment (bending) loads. So no – you should not use any type of bracket on top of your slab. Your best bet will be to build around slab with posts properly embedded in ground.



Posts Out of Ground, Brackets Wrong Orientation, and a Rebuild

This week the Pole Barn Guru delves into reader concerns over use of a thickened edge with brackets instead of embedded columns in and area of northern Minnesota with heavy snow loads and lots of rain, the issues with wet set brackets set in the wrong orientation, and the prospect of rebuilding over current slab with existing building that is too small to fit needs.

DEAR POLE BARN GURU: Hello, I see your communications on here a lot so figure I would take a shot at asking you some questions. If you’re not interested in wasting your time I understand and disregard. I am trying to plan out a future build for a pole building probably 36x46x16 to heat and store a RV in. My area in Northern MN gets heavy snow and lots of rain so I think posts out of the ground would be best (mounted to slab). So we would do a thickened edge like we did with our home. Is there any semi-basic logic to what kind of thickened edge would be required or does it need to be calculated by an engineer? SHAINE in DULUTH

DEAR SHANE: Always happy to help. Thickened edge slabs are most often used in areas of little or no frost. It most instances, it is going to prove most cost and performance effective, to use embedded columns. Properly pressure preservative treatment (UC-4B rated) columns will outlast your grandchildren’s grandchildren, even in areas with profuse rainfall. If you do opt for a thickened edge slab, then it will need to be properly insulated (or extend downward to below frost line) to prevent heaving. Whoever provides engineer sealed plans for your building, can properly detail foundation depending upon route you ultimately pick.

Sidebar – if you have the space, consider building 36′ x 48′ as it will be nearly identical in investment due to efficiencies of material usage.


DEAR POLE BARN GURU: Builders put wet sets in wrong set 2×8 4ply glu lams columns now the laminated side is running with the face not the trusses. How much strength did I lose how can I fix it without demolition? 62ft trusses 80 ft long 10 ft post spaces in front (it’s open) back is 12 ft spacing with an additional 18ft lean to. Main building is 14ft high. KURT in HAGERSTOWN

DEAR KURT: Do-it-yourselfers just do not make mistakes such as your ‘professional’ builder just has, because they will actually look at plans, follow instructions and use common sense. 4 ply glulam columns measure 5-3/8″ x 7″ Column strength in bending is based upon Section Modulus (Sm). As designed, Sm – 5.375″ x 7″^2 / 6 = 43.896, as placed by your builder 7″ x 5.375^2 / 6 = 33.706, so you are losing over 23% of your bending strength. You have a bigger problem than strength of column – wet set brackets are not designed to take a load when rotated 90 degrees. Sadly, sounds to me like your builder has an expensive demo on his hands.


DEAR POLE BARN GURU: I am looking into a property with an existing pole building on a 24×40 slab (construction history unknown, it’s old so there might not be any). The building is too short for my needs, and is also pretty worn out overall. My question is would I be capable of taking down the current building and reconstructing my own on the current slab? Would it be possible to have the slab inspected as to know it’s exact structural capabilities? Would it be best (or even possible) to have a 2′ skirt with footings poured and tied in around the entire perimeter, and just build a larger building on that as to avoid the structural limitations of the current slab? Thanks! BEN in ZIMMERMAN

DEAR BEN: As no building is ever too big, I would look to build outside of existing slab, then infill.

Rather than pouring footings – use properly pressure preservative treated columns, embedded in ground. Will prove structurally superior, easier to build and far less costly.

Continuous Foundations, Column Spacing, and Inside Closures

Let’s finish off the week with one more day of Ask the Pole Barn Guru. Today Mike takes on reader questions about connection with a continuous foundation, benefits of 10′ or 12′ column spacing, and replacing inside foam closures.

DEAR POLE BARN GURU: Hello. We are located in Ohio. We would like to build a 24×40 pole building. Zoning says it needs to be attached per their rules so we plan to attach with a simple fabric awning to meet zoning. The county says we need a continuous foundation if it is considered attached. Stupid right? The only thing touching both building will be a fabric awning. I have been told we can have an engineered foundation, or a 6″ by 38″ deep concrete wall poured, wood foundation or a traditional block foundation. Where would I begin to find details for an engineered foundation? I am struggling finding the info and where to start. RALPH in POLAND

DEAR RALPH: In a typical fully engineered post frame (pole) building isolated columns embedded into your ground would be complying and meet Building Code requirements. We would like to see your jurisdiction’s written requirement for mandating a continuous foundation, as often times these ‘requirements’ are just one person’s own feelings of how things should be done, rather than having an actual basis.

Should this indeed be an approved statute, we can have your new building engineered with your continuous foundation of choice. One of our Building Designers will be reaching out to you to discuss further, or dial 1.866.200.9657 for immediate service.


DEAR POLE BARN GURU: Are there any benefits going with 10′ centers over 12′ centers? I was thinking about going with 10′ centers because in my mind it seems like that would be a stronger building and would have less purlin sag over the years but rather go with 12′ centers to gain more parking space for a leanto? Any recommendations? Thanks BRIAN in PARRISH

DEAR BRIAN: Regardless of spacing of columns or trusses, a fully engineered post frame building will be designed to meet or exceed a specified set of wind design criteria – speed and exposure. You are better served to increase design wind sped, so your entire buildings is capable of supporting higher loads, than to merely move columns closer together. Provided Code required deflection limitations have been properly engineered for, any purlin sag, over time, should be relatively imperceptible.


DEAR POLE BARN GURU: Greetings, My metal roof is 15 years old and the inside foam closures have deteriorated.  1.  Are they necessary, and 2. if so, how does one replace them?

I hate to remove the screws along the eaves (or maybe even more screws farther up each panel), but see no other way to get replacement closures under the metal panels.

I’d appreciate any advice


DEAR SHERRY: Properly manufactured inside closure strips are UV resistant and should outlive your building’s steel roofing. Personally, I find them essential, as without them small flying critters have a clear path to enter your building. In order to replace them, you will have to remove screws along your eave line. Once remains of old closures are removed, new ones can be put in place. Old screws should be replaced by both larger diameter and longer screws, to maintain integrity of connections and prevent leaks.

For extended reading on Inside Closures https://www.hansenpolebuildings.com/2015/12/the-lowly-inside-closure/



Build on a Slope, Joist Hangers, and the Future of Post Frame

This Monday the Pole Barn Guru answers questions about building on a slope with use of embedded columns or brackets on piers, the proper installation of joist hangers, and the Guru’s vision of the future of post frame construction.

DEAR POLE BARN GURU: Because of the 16% slope, I will be using concrete piers & posts to support a traditionally framed floor which will have 1-1/8″ tongue & groove plywood decking. My question — can Hansen provide a design for my timber frame shop which will have a loft? The size of the building will be 36′ x 16′ and the loft 36′ x 24′. KEVIN in SHERWOOD

DEAR KEVIN: We can design and provide your new building as a fully engineered post frame building with either embedded columns, or columns mounted to brackets on piers – basically a ‘stilt’ house type design.


DEAR POLE BARN GURU: Hello, I’ve got a question about the proper installation of the LU joist hangers.

I’m nailing them to the trusses through all the holes in the bracket, but when it comes to nailing them to the purlins using the 10d 1-1/2″ nails, it would seem like I should alternate holes as to not interfere with the nail on the opposite side. The holes that allow nails to be placed in the purlin side of the hanger are not directing the nail in at a 45 degree angle like some others I’ve seen, so just wondering if I should just be directing the nail in to slightly offset the other side? Just seems like a lot of nails in a small area if I do that.

Either way works for me. Just want to be sure I’m not mistakenly compromising anything by installing all those nails. BOB in MOSINEE

DEAR BOB: Weirdly enough I have installed probably tens of thousands of joist hangers and had seriously never given a thought to this (or experienced a challenge). Obviously the engineers at Simpson Strong-tie have thought this all through in designing these parts. I would think even if you were able to drive nails in from opposite sides perfectly so as they would hit each other, the point of the nail from one side would tend to deflect the nail from the opposite side. In all reality, because the holes are so close to the truss, the nails are going to be driven in at a slight angle (whether driving by hand, palm nailer or a gun). Installing all of the nails should not compromise the wood.

DEAR POLE BARN GURU: How do you foresee the post-frame market in the next 3-5 years? SCOTT in CHICAGO

DEAR SCOTT: I feel post frame construction will be the largest growth market in construction over the next five years. It is becoming increasingly popular as residences, especially with people fleeing big cities. Post frame buildings afford many opportunities not seen with other structural systems – minimal concrete for footings, easily erected DIY, easy to super insulate, rapid construction, vastly customizable.



Bigfoot Systems

Bigfoot Systems®

Bigfoot Systems® bills itself as North America’s Original #1 Selling Pier Footing Form, which I would say is most likely 100% or more correct.

So, what exactly is a Bigfoot and why would one use one?

Before we get carried away, I have never used a Bigfoot and this is not a celebrity endorsement. This article began with Hansen Pole Buildings’ Designer Greg Lovell asking me what I thought of the system.

Bigfoot is a footing form which is used to form a pier base under a cardboard construction tube (think Sonotubes: https://www.hansenpolebuildings.com/2013/11/sonotube/).

Unless one wants to make a significant investment in concrete filling a very large diameter tube, it is more economically practical to increase the size of the footing (maintaining a smaller diameter tube) in order to properly distribute the downward forces over an adequate surface.

In a previous article we shared why it takes a fairly large footing to spread the weight out (read more here: https://www.hansenpolebuildings.com/2012/08/hurl-yourconcrete-cookies/).

There are some limitations as to the “smallness” in diameter of the cardboard tube. In cases with concrete encasement around an embedded column, Code requires a minimum of four inches of thickness of concrete on all sides of a column. The diagonal measure across a nominal 6×6 (actual 5-1/2 inch by 5-1/2 inch) column is just under eight inches, meaning the smallest possible Sonotube would be 16 inches in diameter.

While Bigfoot comes in 20, 24, 28 and 36 inch diameters. Only the largest size will accept a tube over 12 inch diameter.

I am certain Bigfoot offers advantages for many types of construction, especially with decks. For post frame construction, in most cases it appears as if it would be added effort and expense. In order to be utilized with an embedded column, a 36 inch diameter or greater hole would have to be dug – and rarely are auger bits this large readily available.

The only true practical case I could make for the use would be if one had soil which collapsed as the hole was being dug – thereby forming a crater.