Tag Archives: post frame foundation

Post Footing and Site Leveling

Post Footing and Site Leveling

Reader KEVIN in PAOLA writes:

“I’ve been working with Cory on my building design and had a question regarding leveling my site and setting my posts. The plan is a 40′ x 60′ building with a 17′ eave height. On the south side, there will be a 12′ attached shed that is open. Based on the elevations I’ve shot, I’ll have to add approximately 4′ of fill on the east end of the building and it gradually tapers all the way to the west end. Now, rock on the property is rather shallow. I dug a test hole on the east end which will require the most fill and the rock is about 2′ below native ground level. I’ve encountered solid limestone that is approximately 2′ thick when digging corner posts and I’ve found locations where the rock is fractured and can be dug out with an excavator. The county requires poles be installed at a minimum depth of 4′, but will allow 30″-40″ if due to rock and if the holes are backfilled with concrete.

· How would you design the foundation for the poles?
· Does the 4′ of backfill count when measuring post embedment?
· Would you set the posts first and then add the fill?
· Do you change post foundation design as you move from the deeper fill for elevation on the east end to fill on the west end that is replacing the top soil?
· Does the post foundation design change for the open shed on the south side?

I’m attaching the design doc from the county. Foundation information is listed on pages 8 and 9.

I hope all of this makes sense and thank you for the help.”

Thank you for reaching out to me. With your permission, I would like to treat your building as if it was my own (in other words, What Would the Pole Barn Guru Do?).

Project# 05-0211Starting with your door end (which I will assume is uphill), I would add enough fill so this end could have holes dug to 40″, filling balance of site accordingly. All fill should be compacted in no less than six-inch lifts to a minimum of 90% of Modified Proctor Density (you may need to invest in a Geotechnical Engineer to verify compaction).

Foundation would be embedded columns to 40″ depth and would be same for all areas (our engineers will seal holes at 40″ depth) Properly compacted fill can be relied upon to be equal to undisturbed soil Fill first – it is so much easier than trying to work around columns.

On door end, you will want to grade away from doors, so water coming down hill does not end up running into your building.

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.



A Basement Foundation, a Leaky Roof, and Raising Bays

Today’s “Ask the Guru” tackles reader questions about erecting a kit on a basement foundation, how to find and repair a leaky roof, and some advice on raising bays to add height to a structure.

DEAR POLE BARN GURU: Is it possible to erect one of the pole barn kits on a basement foundation? LUCAS in LANDISBERG

DEAR LUCAS: Fully engineered post frame buildings adapt themselves very handily to being erected over a full, partial or walkout basement. We can engineer to have wet set brackets placed in concrete, concrete block or ICF foundation walls, or can provide post framed Permanent Wood Foundation walls. We encourage our clients with basements to utilize clearspan wood floor trusses, to create wide open spaces in basement levels, as well as to allow for utilities to be run through floor trusses, resulting in flat finished ceilings.


DEAR POLE BARN GURU: My pole building is 35 years old, the roof is leaking, how do you find where the water is coming in, it is nailed, should I replace the nails with screws? PETE in DU PERE

DEAR PETE: Older steel roofs most usually develop leaks at eave lines, closest to endwalls first. This is where greatest wind shear stresses occur.

Always wear appropriate safety equipment when on a roof.

You should replace all nails with screws of a larger diameter than nails and 1/2″ greater in length. Look for screws with EPDM washers (not neoprene rubber). If you find a location where water leaks have caused wood deterioration and screws are not “biting” place a wood ‘filler’ in hole – we’ve heard of people using wooden match sticks for this purpose, however would recommend ripping some small squares (roughly 1/8″ square) out of Douglas Fir using a Table Saw.

Once all nails have been replaced, you can test for leaks by using a hose and running water on roof. Start with eaves and work your way towards ridge line. It does take an observer inside to advise if any water is coming through.


DEAR POLE BARN GURU: I am considering buying land with an existing 36×96 pole barn on it. The building has 10′ doors and the trusses are 12′ height. I have one truck that requires a 12′ door and clearance. It was suggested to me that i could raise one or two bays on the end of the building by sistering to the existing poles and lifting the roof two or four feet to make clearance, reuse the trusses and roof and add metal to the sides. My questions are is this possible and what should I be aware of to make sure the job is done correctly. Snow load is not a concern here and the building has a concrete floor. No heat or AC just storage. Thank you CRAIG in INDEPENDENCE

DEAR CRAIG: While it might be possible to raise a portion of the roof, it should only be done with involvement of a Registered Professional Engineer who can make a determination of adequacy of what you have, and what would need to be done to insure structural adequacy. Chances are good columns in area to be taller will need to be larger in dimension to properly withstand wind loads.

Foam Boards, Foundations, and Rat Walls

Today the Pole Barn Guru answers reader questions about adding kraft-backed insulation to rigid foam boards, if posts go in the ground or a foundation system, and if a pole building needs a “rat wall” poured.

DEAR POLE BARN GURU: I have an existing pole barn, the front portion being 30×30 with 11′ walls. The walls have R tech faced rigid foam board between the girts with the reflective side facing the shop interior. The shop is only heated when I work out there by a vented propane unit heater. The walls will be finished off with steel liner panels. My question is can kraft faced fiberglass insulation be placed over top of the rigid foam board that is “foil faced” with the kraft paper backing facing the interior of the shed (back of liner panels)? JACKSON in COLEMAN

DEAR JACKSON: You should use unfaced batt insulation to avoid creating a situation where insulation is being trapped between two vapor barriers. It may prove necessary to dehumidify your shop space due to wall drying to interior, especially if your concrete slab on grade does not have a vapor barrier beneath it.


DEAR POLE BARN GURU: Do all your post go directly into the ground?  Do you have any type of foundation system? Thanks TONY

DEAR TONY: Our most common design solution utilizes properly pressure preservative treated columns (UC-4B rated) embedded in ground, with bottom of column hole below frost line (or 40″ below grade, whichever is greater). If potential decay of columns is a concern (https://www.hansenpolebuildings.com/2020/09/pressure-treated-post-frame-building-poles-rot/) we can provide plastic sleeves to isolate columns from surrounding earth. We can also design using columns mounted to wet set brackets to either be set in piers or atop of a foundation wall or thickened edge slab. We have also had clients utilize concrete Permacolumns, however this is rarely a cost effective choice https://www.hansenpolebuildings.com/2018/04/perma-column-price-advantage/.


DEAR POLE BARN GURU: Building a barndominimum what or how do you get a foundation or rat wall with pole construction do you dig out between the poles and pour it? LLOYD in ONSTED

DEAR LLOYD: There is no structural reason to pour a “rat wall” between columns (https://www.hansenpolebuildings.com/2012/06/rat-wall/).

My recommendation (and we can show this on your engineer sealed plans provided with your building) would be to use 19 gauge, 1/2″ x 1/2″ galvanized wire mesh around your building’s perimeter to a depth of three feet. This can be done be means of a trench and will be far less expensive than pouring a wall between columns.






Foundations – Post Frame Keeps It Simple

Post frame (pole building) construction affords a plethora of savings for a new building owner, chief amongst these are foundation simplicity. I’ve previously expounded upon foundation savings in post frame construction as compared to stick frame buildings: https://www.hansenpolebuildings.com/2011/10/buildings-why-not-stick-frame-construction/.

Today I will add some graphics to reinforce (pun intended) complexities of non-post frame foundations.

Excavation, rebar and welded wire mesh in place for a thickened edge slab foundation for stud wall construction. In this case slab edges require a double row of rebar where thickness will be 16 inches. This foundation and floor system assumes a light weight building and must be poured upon undisturbed or properly compacted soil with adequate load bearing capability. Shallow foundation and concrete slab on grade are poured concurrently.

For an engineered steel building, foundations are more complex than for post frame construction. There is a continuous footing and foundation wall around the building perimeter, with reinforced piers to support steel column bearing points. Piers have embedded anchor bolts (requiring exact and accurate placement) to attach steel frame bases.

Top of foundation wall allows for attaching steel wall panels as well as support for any masonry veneer, if required for aesthetic purposes. Each steel column base has a rebar hairpin (usually two 20 foot long rebar sticks). These hairpins tie columns into concrete floor to reduce the tendency of column bottoms to move outward when loads are applied to the building.

Post frame (pole barn) construction utilizes a low-tech foundation system able to be successfully completed by even semi-skilled workers or an average DIY building owner. Face it, augering a hole in the ground makes for a fairly simple and affordable foundation system – eliminating any need for extensive excavations, often with a need for expensive equipment.

Looking for a design solution for your new building with flexibility and cost effectiveness? In most cases, look no further than post frame construction!


Poured Foundation or Block: Neither!

What’s better: A poured foundation or block? How about – neither? Try post frame footing design!

Even though my lovely bride and I are now living 98% of the time on the eastern border of South Dakota, I still read the online version of my formerly local newspaper – The Spokesman Review, from Spokane, Washington. This morning’s edition (November 12, 2016) had an article written by Tribune Content Agency columnist Tim Carter titled, “What’s better: A poured foundation or block?” The article can be read in its entirety at: https://www.spokesman.com/stories/2016/nov/12/whats-better-a-poured-foundation-or-block/

The gist of Tim’s article is the strength of either a poured concrete or a block foundation comes from the judicious and frequent use of steel rebar (learn more about rebar here: https://www.hansenpolebuildings.com/2016/01/rebar/).

Tim’s article does ponder somewhat the cost of the two choices presented. Whether the foundation is blocks or poured concrete, neither is for the faint of heart, or light of pocketbook. I’ve elaborated at length on this very subject, as opposed to a far less expensive alternative – post frame here: https://www.hansenpolebuildings.com/2011/10/buildings-why-not-stick-frame-construction/.

When it comes down to foundation costs and what choice to pick, the vast majority of potential building owners are just not aware of post frame footing as being an alternative.

Why is this?

Several reasons – the largest of which is lack of education to the general public, building officials and building contractors about post frame footing design.

The National Frame Building Association (NFBA) has long been the advocate for educating the public as to the Code conformance of post frame construction. This story was published in Frame Building News magazine and is quite appropriate to this subject: https://www.nfba.org/uploads/Advantage_-_Its_Code_Conforming.pdf

To give a perspective on why the message of the NFBA is lost in the shuffle, according to the United States Census Bureau, 2013 construction of all buildings in the U.S. was roughly $930 Billion. The post frame industry was somewhere around $7 billion (or under one percent).

Considering a new low-rise building (in most cases three or fewer stories and a wall height of 50 feet or less) in your future? Give a look at post frame construction – it could very well save you both money and time, while offering some unique design features and advantages!