Tag Archives: sonotube

Repairing Rotted Lester Building Poles

Repairing Rotted Lester Building Poles

Reader KEVIN in OELWEIN writes:

“I own a Lester’s (Company name) pole barn machine storage shed on my farm that was built in the late 1970’s. It needs new metal put on the roof. It is 50′ x 80′ with a concrete floor. Some of the poles are rotting just below the soil surface. About 15% of them. So those poles would need to be replaced top to bottom, or perhaps just the bottoms, before doing any other work on the shed. Are there ways for me to replace or repair these rotted pole bottoms on a standing building? I cannot find any contractors who will do the work. Thank you.”

Mike the Pole Barn Guru says:

Sadly, prior to about mid-1980’s, many treatment plants would do what was known as “.60 or refusal” for CCA pressure preservative treating. This resulted in difficult to treat timbers (such as Douglas-Fir) being basically painted green with preservative chemicals, as only minimal penetration would occur. Even with this, many have survived adequately in service for decades.

Provided column holes were not backfilled with pre-mix concrete (they probably were not), you could temporarily support any given deteriorated column above grade, then cut off the column just above top of concrete slab. From outside, excavate around offending column and remove it. Coat cutoff column bottom end with a waterproof sealant, such as an asphalt emulsion. Place a Sturdi-Wall Plus® wet set bracket on bottom of cutoff upper portion of the column. Clean all loose dirt from bottom of excavation. Use an appropriately sized Sonotube® extending down to at least below frost-line and backfill tube with premix concrete. Backfill around exterior of tube with compactable fill, compacting to at least 95%, no less often than every six inches.

For a rough idea of required Sonotube® diameter take roof snow and dead loads (should be 30 psf or less) x 50′ span divided by 2 x post spacing (most agricultural Lester Buildings are posts every 10′) to calculate weight to be supported.

Example: 30psf x 50’/2 x 10′ = 7500#

Most soils will support 2000 psf, so 7500# / 2000# = 3.75 square feet (required area of sonotube).

A 24″ sonotube has an area of 3.14 sft, 28″ would give you 4.27 sft.

A Registered Professional Engineer should be retained to verify adequacy of soil bearing capacity, as well as diameter of tube.

For extended reading on Sturdi-Wall Plus® brackets: https://www.hansenpolebuildings.com/2019/05/sturdi-wall-plus-concrete-brackets/


And some thoughts about Sonotubes®: https://www.hansenpolebuildings.com/2013/11/sonotube/

Rock Letters

Hansen Pole Buildings’ Designer Doug recently sent this message to company owner Eric and me:

“I’m getting the question regarding rock letters from Clients and builders in central and eastern Oregon. 

Have we, or do we ever send the building department a rock letter regarding buildings where optimum post hole depth is not achievable?”

When I was building, a Volkswagon sized rock was generally parked and could be found in any given project’s last hole to be dug.

With all other holes dug – moving the building to avoid a rock just never felt like a viable option. I hated digging holes to begin with as they always entail dealing with unknowns, what is lurking beneath the ground’s surface. RMS Titanic’s Captain Edward Smith must have had some of these same feelings about icebergs, you never know what is below the surface until you hit it.

I used to take a steel stake used for anchoring concrete forms and a sledge hammer to investigate job sites prior to digging. Once building hole locations were laid out, said stake could be driven in at each hole location to determine if there were challenges ahead which could not be seen on the surface. At least by doing this stake test, we could determine with some degree of accuracy where challenges might lay, and if we thought we were going to have one, negotiate with our new building owner about shifting building location to avoid isolated rock.

My first choice for a solution would be to dig said rock out. Even if it leaves a crater numerous feet across, a sonotube can be placed at this column location, properly backfill around and column can be placed in the sonotube. This excavation is probably going to involve some heavier equipment, like a backhoe.

Behind door number two – rent a jackhammer. Unless you have hit solid granite, most rocks can be broken apart by use of a jackhammer and physical exertion to operate it.

Or a third choice (and often most practical) rent a “ram hoe” (aka concrete breaker) attachment for a skid loader or backhoe. This Hydraulic Breaker makes quick work out of a tough job. With a smart and efficient design it provides a workhorse with only two moving parts. Vibration and shock are controlled by shock absorbing polymers, minimizing machine wear and sound while improving operator comfort level. One can easily smash through concrete, even on an incline, with hardest hitting breakers in their respective impact energy classes. It has only two moving parts, one grease fitting. Also features low recoil and minimal hydraulic pressure spike, as well as unique trapezoidal shock wave for greater breaking power.

Eric’s response to Doug was, “When they can’t achieve designed depths required as shown on plans they would need an engineered fix.  No simple letter resolves the fact they could not get down to depths shown on plans. If they don’t go to use of wet set brackets a fix can be a variety of solutions depending on the rock’s size and depth. Previously our engineers have had clients who hit bedrock epoxy rebar into hole bottom bedrock to connect to concrete column encasement. Shale or other easily chipped rock doesn’t work for this solution, so it really depends on individual situations. In each case our engineer of record has to review circumstances, arrive at a design solution and client will incur costs to do so. “

This last option is not one to undertake on your own without an engineer’s involvement. You don’t want this to become a weak link resulting in failure of your beautiful brand new building.

Tipping Up Post Frame Walls

Reader JIMMY in ROCK HILL writes:

“I want to get your opinion on the pole barn building method seen in the linked video. (RR buildings) https://www.youtube.com/watch?v=fVwUl4cm8fQ I am impressed at the built in efficiency of his process. Is there a benefit to his post ground connection, (i am aware that his method will use lots more concrete. and I assume those brackets aren’t cheap)
I know you don’t recommend attaching the girts till after trusses are on…
I’d appreciate your thoughts.”

Rural Renovators has done a fabulous job of producing videos – if nothing else it is helping to make awareness of post frame construction more widespread. There have been over a million views of this particular video alone!

Things to consider with this method of mounting columns, rather than embedding them – cost of sonotubes (an 18″ diameter tube 4′ long will run around $20), a little over twice as much concrete will be needed for holes (roughly $15 on an 18″ diameter hole), brackets (roughly $50 plus shipping) and mounting hardware. This will be offset slightly by columns being four feet shorter in length. Due to soil bearing capacities, there are many instances where larger diameter holes will be needed, but for this discussion’s sake – probably $75 per hole in minimum added investment is not unrealistic.

As to a structural benefit, I personally prefer to avoid creating a hinge point at grade. Embedded columns take away needs for this connection and connections are a wink link in any structural system. Let’s face it, placing a relatively small column in a relatively large hole and shifting it to where you want it is pretty low tech and fairly forgiving.

Rural Renovators accurately sets all column bases to an equal height, allowing for walls to be framed on ground and tipped up. This does require the use of one or more pieces of equipment – ones your average DIYer does not own, so would have to borrow, or in most cases rent. Due to end and sidewalls sharing common corners, it precludes being able to frame up two walls completely on the ground.

In most cases 2x girts placed wide face (barn style) to wind do not meet Building Code requirements, making bookshelf style girts a common structural solution. On buildings without eave overhangs (extended truss tails) trusses can still be raised straight up column sides with barn style girts, however bookshelf girts take this option away. This means lifting equipment would be necessary to get trusses into place successfully.

For Rural Renovators, they have built themselves a niche in their geographic service area by doing things differently than any possible competitors. This is at the very least brilliant marketing – as when everyone constructs things identically, it forces price to become a defining difference!

How to Re-level a Garage

Auntie Em, Auntie Em My Garage Has Lifted 

Well, it wasn’t from a twister and this article has nothing actually to do with Auntie Em or actress Clara Blandick who played Auntie Em in 1939’s film classic The Wizard of Oz. For trivia buffs, Blandick also played a part in 1937’s original A Star Is Born.

Reader GEORGE in LAGRANGE might be wishing a twister had hit his garage, so insurance would pay for a replacement. George writes:

“Due to the freezing and thawing cycle my pole garage has lifted about 7 inches since it was built 12 years ago. You can now see the outside grass from inside the garage. And it has not lifted evenly so the garage is unlevel.”

George’s post frame garage has some challenges, none of them ones with an easy fix. How did his garage get this way? There are three possible major contributors to this garage’s current situation. These would include:

Inadequate site preparation

At a minimum, site preparation includes:
· Remove all sod and vegetation.
· For ideal site preparation, remove topsoil and stockpile for later use in finish grading. In frost prone areas, remove any clays or silty soil
from within future building “footprint”.
· Replace subsoil removed from around building with granulated fill to help drain subsurface water from building.
· Distribute all fill, large debris free (no pit run), uniformly around site in layers no deeper than six inches.
· Compact each layer to a minimum 90% of a Modified Proctor Density before next layer is added. Usually, adequate compaction takes more than driving over fill with a dump truck, or
earth moving equipment.

For more details on proper site preparation please read: https://www.hansenpolebuildings.com/2011/11/site-preparation/

Column Depth

Bottom of column encasement needs to be below frost line. This is a no-brainer.

Water

Read more about what causes frost heaving here: http://www.hansenpolebuildings.com/2011/10/pole-building-structure-what-causes-frost-heaves/.

There is going to be no easy or inexpensive fix to George’s situation. An investment into a geotechnical engineer who could provide a thorough site evaluation along with solutions might be money well spent.


Building could be brought back to level by excavating at each raised column to well below frost depth. Cut off columns at base of splash plank (while supporting building from falling), then remove embedded portion of column. Place an appropriately sized sonotube in excavation with top of tube at grade. Pour premix concrete into tube and place a wet set Sturdi Wall bracket – expertly placed to receive upper portion of column. https://www.hansenpolebuildings.com/2013/11/sonotube/

If all of this sounds daunting (it would be to me), a consideration could be demolition and start over from scratch.

The Case of the Frost Heave and a Pole Barn Porch

Allow me to preface this post about a frost heaved porch with a reference to Sherlock Holmes.

Sir Arthur Conan Doyle’s Holmes and Watson solved fictional criminal dilemmas with deductive reasoning. In my cases, nearly 40 years of experience (plus knowing and relying upon input from many brilliant engineers) allows me to recommend solutions with a fair degree of certainty as to their outcome.

Reader RICHARD in WOOD STOCK brought to me this interesting case:

“My concerns pertain to my 50 foot by 72 foot pole barn which was built in 2008.
The barn has a brick paved porch that wraps around the length of the barn on the south side of the building. The interior of the barn has a cement floor, poured at the time of construction.

The barn has been very stable and sturdy since it was built, that is until this winter.
Shortly after the subzero weather we had in northern Illinois back in January, I was checking the barn for any issues and noticed that the pavers at the end of the porch had heaved up and the soffit of the porch was no longer level. Upon closer inspection I found that the two last support poles for the porch appeared to have heaved up causing the porch to lift and pull away from the barn to the point of wrinkling the steel siding. I have been closely monitoring the situation and have noted that the porch continues ton move up and farther away from the barn. M

Mike the Pole Barn Guru responds:

I’d say Richard is probaby correct as to heaving cause. His building might get some degree of return to normalcy after Spring thaw, however probably not back to straight and level.

Without involving services of a geotechnical engineer, who could actually do an onsite evaluation – about best I can offer will be how I would probably attack this challenge. I’d temporarily support the porch in the heaved column area. Cut both of these columns off at grade. Excavate ground below columns to remove embedded portions. Excavation needs to be deep enough so bottom of hole will be 1.5 times frost line depth below grade (probably around six feet). Place an appropriately sized Bigfoot® (https://bigfootsystems.com) in excavation bottom with a Sonotube® (https://www. sonotube.com) above. Use Sturdi-wall Plus wet set brackets (https://www.hansenpolebuildings.com/2017/05/sturdiwall-brackets/) in top of concrete poured in Sonotubes® to attach remaining portion of columns. All of these above suggestions, as well as proper sizing of Bigfoot and diameter of Sonotubes®, should be confirmed by a Registered Design Professional (RDP – architect or engineer), ideally whomever designed your building originally. Moving ground water away from your building will also prove to be an excellent idea to reduce or eliminate future challenges from frost heaves.

 

For extended reading about Bigfoot® Systems and Sonotubes® please see https://www.hansenpolebuildings.com/2018/05/bigfoot-systems/  and https://www.hansenpolebuildings.com/2013/11/sonotube/

Miracle Truss Concerns

One of the great things about being the Pole Barn Guru is helping people who have construction challenges of all sorts – even those who do not have post frame buildings.

Here is a recent one:

Hi Pole Barn Guru, and thanks for your informative website and blog. I’m using email rather than the website question portal so I can include pictures. I’m a contractor, but my normal specialty is finish carpentry. I wouldn’t normally take on a pole building job, but this one is for my father so I’m helping him build it to try to save some money.

We’ve acquired a 51 x 120 ft building package made by Miracle Truss, a company which is apparently out of business, hence the lack of manufacturer support. The building was purchased years ago by a businessman who never put it up and finally decided to donate it to a church for a write-off. Long story short it eventually made its way to us, still palletized as new, for an incredible savings. So off the bat I’ll apologize for not buying a product from you, as we already have one. But I’m hoping I can use your expertise and perhaps do business in the future.

In case you’re unfamiliar with Miracle Truss, their design uses open-web steel trusses with owner-provided wood purlins and girts. Clips are welded to trusses to receive wood members. The design gives the strength and span benefits of metal with some of the economy of locally sourced lumber. It seems like a good design, but we’re still only in the planning & groundwork stages. The package includes Metal Sales siding and roofing.

My question relates to the use of “splash planks” on a metal-sided building. I know the purpose of the splash or skirt board in typical construction, but I’m doubting its necessity in this particular design. As you can see in the attached pictures, their plans call for a treated 2×6 splash plank which is used as the outside form board when pouring footings, with anchor bolts pre-installed, and then simply left in place and attached to the sill purlin. This places the outside plane of the wall 1-1/2″ outside of the concrete footing. There’s nothing wrong with this design of course, I just wonder if it’s necessary. I’m considering eliminating the permanent mud board, removing the concrete forms and using the sill (bottom) purlin to attach both the flashing and sheet. The last picture is a quick drawing of what I have in mind.

This means I would have to form my foundation 1-1/2″ outside of the stock plans, but save me 340 LF of AWW 2×6. Any thoughts on eliminating the outside splash board?

I’m also trying to decide the dimensions of my footings. Each post will sit over a buried Sonotube pier with a Bigfoot base, which will bear the weight of the building. The footing is really just a concrete”tie beam” and provides a sill for the walls, without really bearing anything. The total thickness of the wall is 17.5″ at the posts (our posts are W12″ I-beam, plus 5.5″ girt.), but only 5.5″ in between posts. I could form a continuous 17.5″ footing over the top of the Sonotubes (my original plan), or form an offset 8″ w footing to match the outside of the wall. I also am not sure how to choose footing thickness, since it’s not bearing. No guidelines are given for foundation in the package instructions, since climate makes a big difference. We are in southern Alaska, our code frost depth is 4 ft, which is where the tubes will sit. But I’m not sure what the footings should be. Any comments?

Thanks again for any advice you can give. I really appreciate the resources you offer. KADIN in KENAI

Dear Kadin:

Thank you for your kind words. We strive to be informative and entertaining.

IMPORTANT DISCLAIMER: The response below is only in regards to the now defunct Miracle Truss which produced the building package you now own. The Miracle Truss brand name is now held by Spider Steel Buildings, LLC. The current Miracle Truss was formed in 2015 and has no connection with the prior company or its products. According to their attorney, Kevin R. Coan of Hinshaw & Culbertson LLP, the current Miracle Truss can and does provide the lumber package as part of its services. Find out more about the new Miracle Truss at https://miracletruss.com/.

My objections to the defunct Miracle Truss system has always been how does one go about finishing the inside of the building with the steel frames in the way and (very important to most) the having to source one’s own lumber which can end up in a sticker shock situation.

Your Miracle Truss building’s outside 2×6 splash plank is there for a reason, and should be used. The bottom of it is the point at which level grade is on the exterior of your building. If it is not present the steel base trim will probably end up in contact with the ground outside of your building – which will result in premature deterioration as it slowly rusts away.

As to your footings, the best advice I can give would be to contract with a registered professional engineer in your area who can do an analysis of the forces upon your building, wind load, snow load, seismic, exposure, et. al. Also the engineer will need to take into account the bearing capacity of the soils at your site.

Good luck and let me know how it all turns out!
Mike the Pole Barn Guru

Dear Guru: Should I Use Concrete Sonotube Foundation?

Welcome to Ask the Pole Barn Guru – where you can ask questions about building topics, with answers posted on Mondays.  With many questions to answer, please be patient to watch for yours to come up on a future Monday segment.  If you want a quick answer, please be sure to answer with a “reply-able” email address.

Email all questions to: PoleBarnGuru@HansenPoleBuildings.com

DEAR POLE BARN GURU: I am planning to build a post-frame house 32×40. I built a 16×16 post-frame barn last Summer as practice and found that I hit bedrock at 2 to 2.5 feet. I know that most post-frame buildings require a 4 foot hole with a concrete footing to keep the post from settling, while also providing lateral strength. I don’t seem to need the depth for settling issues since I’m building on bedrock, however, I lose the lateral strength of a deeper hole. Is there a way to add lateral strength? Also, since I’m not getting that support from a deep enough hole, would it be better to use a concrete sonotube foundation with sturdi-wall brackets to mount my posts?

Thank you – DIGGING IN DOVER

DEAR DIGGING: If you think about it, a sonotube filled with concrete and a bracket on top, is going to provide less lateral resistance than a column in a hole filled with concrete. Depending upon building dimensions, exposure to wind and soil conditions above the bedrock, it is very possible increasing hole diameter and using a complete concrete encasement could do the trick.

As you firm up your plans, we can provide a preliminary hole layout. From this, you can dig the holes and give an exact measure to what point solid bedrock is encountered. This will allow for a design to be created which will minimize the amount of digging and concrete, without negative effect upon your structure.

DEAR POLE BARN GURU: 30×48 pole bldg. was just completed. The 4×6 posts were set on cement cookies 16″ x 4″ every 8′ and then packed with dirt. Is it too late to remedy this situation? Should I dig down to each cookie and pour some cement to encase each post?  The bldg. was just completed last week, so dirt is still freshly packed. What do you suggest? EVENTFUL IN EVANS CITY

DEAR EVENTFUL: It is not too late, but it will involve work which could have easily been avoided. The concrete cookies are not going to be adequate to prevent settling and they do nothing to prevent uplift.

I’d start digging. Make sure the bottom of the hole (directly above the cookie) ends up larger in diameter than the area closer to the surface. You should probably go to two foot diameter and then pour at least 18 inches deep of premix into the hole.