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Training 4


Quebec, October 13th 2017


M. Alexandre Charette Produits Pylex

400 Rue du Parc-lndustriel Shawinigan, QC

G9N 6T5


Subject :        Certification update - Pylex Screw Piles - IBC 2015 Our Reference : S17-130

Within the mandate you have given us, you will find enclosed an update of the required documentation concerning the Pylex screw pile certification used primarily in the residential sector following the application of codes and standards in effect today. It is important to mention that a study on the certification of Pylex screw piles with a diameter of 152mm was produced by Gencotech in 2005 following the implementation of the 2000 BOCA National Building Code (BOCA/NBC) by the Building Officials Code Administrators International (BOCA).


This technical opinion is based on the results obtained of static axial compression tests performed according to ASTM D-1143-81 standard conducted in 2002 and presented on the next page. These tests were conducted on a soil characterized by clay and silt with trace of sand with a consistency ranging from medium to steep, and also a soil characterized by gravel with trace of silt and clay of average compactness.


Following the analysis and the application of a safety factor of 2 required for such work, the allowable capacity of screw piles with a screw diameter of 152mm was measured at 16kN (3484 lb) in the clay and 27kN (6070 lb) in the gravel. It is important to mention that using the most recent international Building Code (IBC 2015) has no impact on the results obtained in 2005 using the BOCA 2000.


Indicatively, a live load of 4.8kPa (100Ib/ft*) must be considered when designing an exterior balcony or terrace. Thus, considering a dead load of 0.63kPa (14Ib/ft*) to reflect the wood of the terrace itself, the Pylex pile having a screw diameter of 152mm can support a tributary area between 2.9m* (30pi“) and 4.9m“ (53ft*) for soils with similar characteristics as previously mentioned.


These values are indicative only. There are many limiting factors to take into account when designing screw piles, including but not limited to: the type of structure of the balcony or terrace, the lateral forces applied to the piles, the type of structural elements, the maximum allowable deflection, other geotechnical parameters, and the climatic conditions specific to the site.


We hope everything to your satisfaction and remain available to answer any questions.

Please accept, Sir, the expression of our best regards.

Gino Pelletier, P. Eng. M.Sc.




Allowable loads for a Pylex pile with a screw of 152 mm diameter (B6")


Note 1:    Allowable loads are established with a safety factor of 2 from results of geotechnical static axial compression tests                   carried out according to the standard ASTM D 1143-81 on October 18, 2002.

Note 2:    The screw pile had a 152mm diameter with plate 4.5mm thick and a shaft of 33.5mm with a thickness of 3 mm and a                  length of 1 200mm.

Note 3:    ASTM D 1143-81 trials took place in Alma clay and sand in the municipality of Hébertville, province of Quebec, Canada.


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