Help! Our Piles Were Poured in the Wrong Spot

The versatility of helical screw piles is unparalleled in the world of deep foundations.  For this reason we are often called upon to help customers out of tricky situations.

A great example is the project below where the design was revised but the foundation plan was not amended to accommodate the revisions, the result was concrete piles for teleposts which were several feet from where they needed to be.  To compound the issue, the error was not noticed until the foundation was poured and the framing process was getting started.

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Using extensions and reaching through floor joists, Postech’s Certified Installers were able to install screw piles to satisfy the design loads.  The result  was a solution that satisfied the timeline and that was a fraction of the cost when compared to traditional concrete piles.

Visit http://www.screwpiling.ca or call Dale Plett, Director of Customer Consultation at Postech Screw Piles Manitoba and NW Ontario – 204.793.0653 to get things back on track when a project has you scratching your head.

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Cottage Lifted and Leveled On Surprising Budget

The traditional process for replacing a shallow foundation like post and pad with a deep foundation such as screw piles includes either a lift of the structure at least 6′ high or the temporary removal and then replacement of the structure on the new foundation.

A lift to 6′ of a typical cottage will range from $20,000 to $30,000 and will vary based on size and landscape.

Once a cottage is lifted or moved off the original foundation, a deep foundation can be installed.  Because the cottage was built with X amount of original supports (likely posts) the same number of piles is typically required.

With a typical deep foundation ranging from $6,000 to $20,000 for a cottage, very quickly the overall cost of a foundation stabilization project can hit $30,000 or more.

Always looking for a better way to serve customers, Postech Screw Piles Manitoba and NW Ontario proposed an underpinning method involving I-beams and that eliminates the need for an extensive building lift or move as well as reduces the number of piles required.

This strategy does involve additional costs such as I-beams as well as labour and could include custom brackets but generally you will come in well under traditional budgets.

Below is a slideshow of a project completed in 2015 where the customer’s cottage was lifted approximately 2 feet from original height and where the foundation was replaced with heavy duty screw piles installed from the perimeter of the building and two through the floor of the cottage.  We have included before, during and after pictures.

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If you have a cottage where you’re tired of Band-Aid solutions or where the foundation outright scares you, visit www.screwpiling.ca and complete or free quote request form or give Dale Plett, Director of Customer Consultation a call directly at 204.793.0653.

 

 

 

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Are Galvanized Screw Piles a Gimmick?

Competition: “We offer no gimmick screw piles.  Don’t pay for things you don’t need such as hot-dip galvanizing.”

What else is the competition going to say when they can’t offer hot-dip galvanized screw piles at an affordable price?

Postech Screw Piles has made a commitment to quality and one area we push heavily is hot-dip galvanized screw piles.  As a result they send a lot of our helical screw piles (like 98%) for hot-dip galvanizing.  You can likely appreciate that the volume discount received is substantial and therefore Postech dealers can offer a top-quality hot-dip galvanized screw pile at an affordable price.

TIP:  Compare pricing before assuming you’re paying too much for hot-dip galvanized screw piles.

Here is a chart demonstrating the difference in screw pile with 1/4″ wall thickness life expectancy between black steel (untreated) and hot-dip galvanized steel.

Corrosion of Screw PIles Chart

1st value in Italics = Minimum Life Expectancy   

2nd value in Bold = 98% Probability of Life Expectancy

3rd value Normal = Average Life Expectancy

Source:  “Helical Piles: A Practical Guide to Design and Installation”, Howard A Perko (2009)

As you can see, hot-dip galvanizing will more than double the life expectancy of a screw pile.

In Manitoba, most soils will fall under high or moderate corrosivity.

Well doesn’t the galvanizing just scratch off?

When the soil has debris or rocks in it, that is where the key advantage of galvanizing is realized.  Galvanizing provides a tough, impermeable coating. Physical damage is still possible (pile hitting or rubbing on rocks), but even when the coating is scratched through to bare steel, it will continue to provide cathodic protection to the exposed steel.  Even a 1/4″ wide scratch to bare steel  will be protected by the surrounding zinc until such time the zinc coating has corroded off the steel.  That doesn’t happen with paint and non-treated metal corrodes faster when scratched.

“Coating damage is most likely to occur at edges and often corrosion begins in the interior of hollow structures, so these areas are where added protection is needed.” – American Galvanizers Association

A hot-dip galvanized screw pile is coated on all surfaces including the interior of the shaft and at the edges.

It is also important to note that Manitoba’s clay soils are typically free of debris and galvanized coatings are usually fully in tact after installation.

If you would like to know more about corrosion of Postech Screw Piles, please contact Dale Plett, Director of Customer Consultation at Postech Screw Piles Manitoba and NW Ontario and request a copy of a technical brief – 204.793.0653 or dale@screwpiling.ca.

Visit our website at www.screwpiling.ca.

 

 

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Torque Monitored Installations – A Best Practice in Screw Pile Installation

“The empirical relationship between installation torque and capacity is considered to be the greatest attribute of helical foundations.” – Helical Foundations… What an Engineer Needs to Know, Structure Magazine (June 2004), Gary Seider, P.E.

In studying the general approach to screw piles across many jurisdictions in Manitoba one could be mistaken that not much has changed or improved with regards to screw pile technology in 185 years.

A trip outside the province or across the border to the US or even overseas would demonstrate that in fact, many advances have occurred and that screw piles are considered a reliable, predictable and suitable foundation solution for residential, cottage, commercial or heavy/light industrial applications.

Based on the sample engineering below, Manitoba building authorities have approved the full capacity rated use of screw piles to support decks, three season sunrooms, ramps, additions, etc.

Sample of Groundhog EngineeringNotes 3 and 4 clearly indicate that the engineer has limited the stated allowable loads to soil with a 1,500psf bearing capacity.  If soil is other, the engineer is not accepting liability unless retained to re-engineer the pile capacity; the common term used by engineers for these notes is weasel clause.

The ground anchors above can be bought and installed by anyone in Manitoba either by hand (walking in a circle with a bar for leverage) or machine (generally with a posthole auger drive), there is no method for accurately determining if the soil is in fact 1,500psf; commonly described as “blind installation”.

Today, across Canada and beyond, engineers and building authorities have moved away from blind installation methods towards the best practice of torque monitored installations.

“The torque required to advance a helical pile can be correlated to soil shear strength.  Torque should be measured on all projects since it provides such an important verification of capacity.” – Helical Piles – A Practical Guide to Design and Installation (2009) by Howard A. Perko, PhD, PE

The National Research Council has extensively reviewed testing performed on screw piles which validates torque monitored installations and has proven screw piles installed in this manner to meet National Building Code (NBC 2010).

Hoyt and Clemence, in conducting 91 full-scale tests, concluded the standard deviation of the predictions using capacity to torque ratio was less than the standard deviation of calculated capacity using various accepted formulas.  (Installation Torque as a Predictor of Helical Pile Axial Capacity (2007) – helicalpileworld.com)

There are several accepted methods for measuring torque which include but are not limited to shear pins, mechanical dial indicator, digital device such as Digga Align, Intelli-Tork or Torque-Pin, anchor drive refusal, hydraulic pressure differential, etc.  Methods for determining torque do vary in levels of accuracy and allowable loads charts may be adjusted by engineers for safety.

A company equipped with torque monitoring abilities generally works with brand specific engineered allowable loads charts which provide allowable loads for the piles based on torque values achieved.  The engineer providing the stamp on the allowable loads charts does not limit their liability to one specific soil value assumption but rather the entire range of torque to capacity values included on the chart; such values might range from 2,000lbs to 50,000lbs or greater.

Comparing two scenarios below, it is possible to see how the two approaches to screw pile installation differ based on liability for failures.

Scenario 1:  A home owner buys 5,000lbs ground anchors at the local building supply store; the brand is pre-approved by the building authority for use in the jurisdiction.  The approval is based on engineering for 1,500psf soil.  The structure, which has loading upwards of 5,000lbs fails.  The engineer points to notes 3 and 4.  An expensive geotechnical investigation concludes the soil capacity was less than 1,500psf; the engineer is not liable.  Looking to hold someone responsible, the home owner looks to the building authority asking how they approved the capacity when soil values in their jurisdiction sometimes are less than the assumed 1,500psf and where it is not possible for most DIY installers to verify their soil’s bearing capacity?

Scenario 2:  A home owner engages the services of a trained professional screw pile installation company.  Using equipment capable of monitoring torque and referencing engineered allowable loads charts, the installer confirms the required capacities are achieved.  Although the torque monitored installation greatly reduced the probability of pile failure, in this extremely rare circumstance a failure occurs.  The engineer references the piling installation report, the torque values achieved indicate the required loading was met, for reasons unknown or that are extremely rare, a failure occurred for which the engineer assumes liability.

Entering jurisdictions where screw piles are accepted for residential, commercial or even industrial use, engineers work with torque values and building officials verify that piling reports with torque value are provided.  If a geotechnical investigation has been completed and soil bearing capacity indicated, design engineers may use such information to pre-engineer screw piles, however they will still reference the torque achieved during installation to verify each pile achieved the desired capacity.

Torque monitored installation of screw piles has become a norm and is considered a best practice which greatly improves the probability that screw piles installed will perform as required.

Building authorities insisting on torque monitored installations using engineered allowable loads charts endorse a best practice, greatly reduce occurrences of pile failure in their jurisdiction and limit their liability.

Customers insisting on torque monitored installation of screw piles greatly reduce the probability of a pile failure and best protect the money invested in piling.

For more information, please contact Stan Higgins, Master Dealer for Postech Screw Piles Manitoba and Kenora at 204.793.0653 or toll-free 1-855-4-PILING or visit www.screwpiling.ca or email stan@screwpiling.ca

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Professional Screw Pile Installation VS DIY Screw Pile Installation

“I have a skid steer post hole auger that should be able to get one of those in the ground.”  A common statement by aspiring DIY screw pile installers.  But… is this a good idea?

Common auger drives mounted to skid steers, back hoes or excavators and that are sold at retailers like Bobcat, New Holland, John Deere, Etc. are quite different from anchor drives which are only available by special order.

What is an auger drive?  A high speed motor designed for earth augers to churn and disturb earth so that a hole can be easily bored.

What is an anchor drive?  A high torque motor designed to slowly and continuously advance a screw pile causing as little disturbance to and shearing of the soil as possible.

Don’t you just need to simply get the pile in the ground?

Alan J. Lutenegger, John Erikson and Nocholas Williams, Departemtn of Civil and Environmental Engineering, University of Massachusetts in their report titled “Evaluating Installation Disturbance of Helical Anchors in Clay From Field Vane Tests” reported on a very interesting experiment which compared a screw pile installed professionally against a screw pile installed in a manner to mimic a DIY installation.  Graph for Screw Pile Settlement

The results provided a very interesting insight with empirical data demonstrating that difference in capacity between professionally and poorly installed screw piles could be up to 2 times higher (see figure).

The report concluded that the quality of screw pile installation effects the disturbance of the soil and thus the performance of a screw pile.

For a professional screw pile installation backed by a performance guarantee contact Postech Screw Piles Manitoba and Kenora at 1-855-474-5464 or 204-793-0653 or visit www.screwpiling.ca.

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Flag Pole Anchored Without Concrete!

Gimli’s beach was recently awarded Blue Flag certification, a voluntary eco-label awarded to select beaches across the world – learn more here:  www.blueflag.org

This meant they needed a flagpole on the beach from which to proudly fly the Blue Flag.  The problem is finding a solid foundation base for the pole in sand soil where it is very difficult to bore a hole for traditional concrete bases.

Did you know that screw piles were invented in the 1830’s as a deep foundation solution for lighthouses which were generally built on sand?  It’s true!

Quickly and easily, Postech was able to install a screw pile into the sand soil.

Gimli Screw Pile Flag Pole Base

Gimli Blue Flag Pole on Screw Pile

For a solid foundation in any soil, including sand, call Postech Screw Piles Manitoba and Kenora at 1-855-474-5464 or 204.793.053 or visit us at www.screwpiling.ca.

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A Screw Pile Failure in Manitoba

Going into our 4th year, Postech Manitoba and Kenora got an opportunity to put our money where our mouth is regarding our 7 year performance guarantee.

Some companies might try to hide the fact that their product performance hasn’t been flawless but we are proud to share a story about a recent screw pile failure in our customers’ own words:

“We could not be happier or more pleased with the service we have received from your company. Given how rocky and wet the soil conditions are at our cottage we knew it would be a challenge to get screw piles down any great depth when we originally had you install them in 2013 under our screen-room. When all four piles made it down 6 feet or more we thought we were home free. As it turned out we were not and the screen-room was raised by the frost this past winter. Your reaction to this news was nothing short of exemplary. Your immediate offer of multiple possible solutions including the option of a full refund confirmed for us just what a class act you and your company are. We chose to have you reinstall each of the piles after taking a long carbide rock bit to the holes in the hope of getting deeper. Your crew worked hard to get the piles down further than they were before, spending about 2 hours on each pile and I believe that all the piles are now 7 feet plus down. Your crew were also very careful not to create any more collateral damage then necessary to complete the task. We are very grateful to you and your guys for all your effort and perseverance given a very difficult situation.

Sincerely,

Jim and Susan Shannon, Steep Rock, MB”

Don’t get us wrong by any means, the overwhelming majority of our customers experience zero performance issues.  But reality is that we don’t live in a perfect world and Manitoba is especially known for extreme weather and soil conditions; although very rare, this likely won’t be the last time we have to honour our guarantee against frost heaving.

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Postech Screw Piles – Extensively Tested in Winnipeg, MB Clay (Famous Gumbo)

In August of 2014 Postech Screw Piles undertook extensive third-party engineer led and supervised testing in Winnipeg’s famous gumbo / clay soils.

The testing site was not ideal, in fact the soil was downright terrible at ~30kPa, highly moist and plastic soft clay soil. The soil content was 83% clay, 15% silt and 2% sand.

Testing Site Geotech

Some companies might have chosen another test site to ensure their products performed at an optimal level, however, we were thrilled to have found less than desirable soil for our testing. It’s one thing to prove your product works in ideal conditions, it’s another to ensure your data remains true when the soil is less than ideal.

One of our goals was to determine the relationship between the torque applied during installation and the overall capacity of the piles. The result was that torque was a reliable indication of capacity to a certain point. Once torque exceeded 4,000lbs-ft it the relationship was less predictable.

Once all the data was crunched by another ISO certified third party engineering firm, it was submitted to the National Research Council for review and consideration in revising the Postech Screw Piles CCMC report 13102-R.

In March 2015 we received our revised CCMC report 13102-R which now includes the data collected, reviewed and verified from the testing conducted in Winnipeg, MB as well as other testing conducted in Eastern Canada. Below are some key points from our new CCMC report:

– New torque installation chart for clay soils up to 9,500lbs; we involve geotechnical investigations when capacities exceed 9,500lbs.
– Expanded torque installation chart for cohesionless soils (sand, silt, granular, etc.) over 28,000lbs.
– 45% more torque is applied when installing in clay vs. cohesionless soils.
– A need for engineering of buildings only, other structures such as decks, sunrooms, gazebos, sheds, docks, etc. do not require an engineer to determine spacing, capacities, etc. unless specifically required by the building officials in the area.
– No need for an engineer stamped piling report on most projects; a certificate of conformity from a Certified Postech Screw Piles Installer is all that is needed.
– Inclusion of piles with shaft sizes ranging from 1-7/8″ to 6-5/8″.
– The addition of double as well as triple helical designs.
– Inclusion of helical sizes from 8″ to 26″.

Postech Screw Piles do not offer the highest capacity screw piles in clay but we do offer a screw pile and installation process that will perform even in the worst clay Winnipeg, MB has to offer. If you don’t want to leave your clay soils project to chance, Postech Screw Piles are an excellent investment.

Locally tested and nationally approved, Postech Screw Piles Manitoba – 1-855-4-PILING or 204-793-0653. Visit http://www.screwpiling.ca for more information or for a copy of our new CCMC report 13102-R email stan@screwpiling.ca.

Posted in Manitoba Soils and Screw Piles, Screw Pile Engineering, Uncategorized | Tagged , , , | Leave a comment

Winnipeg Deck Plans – Free Templates & Tools

Building a deck in Winnipeg, Manitoba isn’t what it used to be.

Often we give our building officials at the City permits office a hard time for not always making a whole lot of sense in the way they do things. One recent change in deck building requirements however, makes a lot of sense.

Previously you could simply take the area of your deck, multiply it by 50lbs/ft2 and then divide it by the total number of support points to get your loading for permits. This is a quick and easy way to do load calculations but you only are getting the average loading.

The City of Winnipeg has recognized that, pile specific load calculations are much better and have made it a requirement in their Deck building brochure which you can access here – http://www.winnipeg.ca/ppd/permits_deck_reqmnts.stm.

The formula for calculating pile loads for a deck in Winnipeg, MB are below:

Pile Load Formula

The formula isn’t quite straightforward and most of our adult brain’s hurt when asked to do math.  So, your local Postech dealer has created some tools to assist customers with determining pile loads:

  1. For Do-It-Yourselfers we have a How To Video walkthrough for designing a deck foundation for piles:  https://www.youtube.com/watch?v=eKTsjVH37F4
  2. For those who want Plug-and-Play we have Free Deck Templates where all the design work and loads are done for you.  If you want to hit the Easy Button visit:  https://yj191.infusionsoft.com/app/page/deckplans

For those who have a unique deck and who require assistance with the foundation plan, give Postech Screw Piles Manitoba and NW Ontario a call at 204.793.0653 or upload your plans to our Contact Form at www.screwpiling.ca and we will be happy to assist you with an efficient and effective deck foundation and pile layout.

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Fuel 4 School Kicked Off!

Imagine heading to school to learn and grow but your basic survival instincts consumed your thoughts with a need for food you weren’t likely to eat until much later in the day.

Postech Winnipeg Screw Piles would like to thank its customers for the ability to found and continually support the Broadway Neighbourhood Centre’s Fuel 4 School program.

Fuel 4 School piggybacks on the Centre’s very successful Kids Cooking and dinner programs. Youth participating in Fuel 4 School may not regularly have a healthy and filling breakfast or lunch; sometimes dinner at Broadway is the only meal they eat that day. Now, with proceeds donated by Postech Winnipeg and a funding agency grant, youth can not only prepare a healthy and filling dinner but also a bagged breakfast, lunch and snack for the next day.

November 18th, 2014 was the official kick off for Fuel 4 School with 20 jumbo bags full of healthy food to fuel the next school day.

Fuel 4 School Preparing Lunches

Fuel 4 School Bagged Lunches

Check out http://www.thebnc.ca for more about the great things happening everyday at the Broadway Neighbourhood Centre or contact Lawrence Mulhall, Executive Director, at 204.772.9253 to find out how to get involved.

UPDATE – FUEL4SCHOOL MAKES GLOBAL NEWS!

http://globalnews.ca/video/2319362/better-winnipeg-fuel4school-program-helps-kids-get-the-nutrition-they-need

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