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Let RedBuilt™ help you with that – A word of caution when modifying or fixing Open-Web trusses.

Posted on August 08, 2012 by RedBuilt


by Wilson Antoniuk, RedBuilt™ Technical Sales Representative for Southern Idaho Did you know that every RedBuilt™ Open-Web truss is custom designed and manufactured for its specific application and loading? Or that we maintain archives of our truss designs and as-built manufacturing reports back to the 1960’s? Or that stiffening a portion of the truss can actually be more detrimental to a truss’ performance than doing nothing? I could go on, but ultimately, all these questions lead to one conclusion:  Repairing or modifying trusses cannot be taken lightly.  So, before you cut or repair a RedBuilt™ product, please take a moment to make certain you're equipped with the knowledge base and information necessary to do it properly keeping in mind that, first and foremost, these structural members are protecting people, and when modified or repaired improperly, can lead to injury or even death of the building occupants in the case of collapse. The best and easiest way for you to tackle repairs or modifications is to get us involved as soon as an issue is identified. This is true whether it is a RedBuilt™ project with Red-I™ i-joists, RedLam™ LVL, or our Red series Open-Web trusses, or an existing Open-Web project originally manufactured by Trus Joist®.  If you are the owner, GC, Architect, Framer, or Engineer, there are mountains of benefits from getting RedBuilt™ involved:

  • We've assisted with the design of thousands of repairs and have the expertise and resources to do it properly.
  • We have over 50 years of archived projects with as-built truss reports as well as a dedicated repair team of designers and professional engineers.
  • RedBuilt™ puts together repair instructions, details, and manufactures repair parts, and special tooling to assure that repairs can be done accurately and with quality workmanship to bring the structural member back to its original design capacity.
  • When RedBuilt™ works with the design professional of record in determining the right fix (if repair is possible), our warranty can remain in effect for the life-expectancy of the structure (Follow this link for more details http://www.redbuilt.com/images/docs/RedBuilt%20Repair%20Memo.pdf).
  • You can be assured that you did the right thing for your customer and the public because you safely solved the problem with the help of RedBuilt™.
[caption id="attachment_437" align="alignright" width="300"] The first web of this truss was removed. Now, the member is supported by 2-2x8 outriggers below top chord in Simpson joist hanger. The roof has dropped and is collapsing (shoring currently supporting structure).[/caption] Sometimes design professionals, contractors, plumbers, or framers take it upon themselves to repair RedBuilt™ products.  After all, they have a ton of experience and can save some time and money by taking care of it themselves.  Unfortunately, this perception is wrong and may have dire consequences. The reason Open-Web trusses are so difficult to fix without our knowledge base is each Open-Web truss is designed specifically for each building.  Designs are based on the clear span, design loads and bearing conditions of the building. In order to get an Open-Web truss to work efficiently, we size each pin and steel tube to carry the load necessary. The next time you see an Open-Web truss, take a closer look at it. You will find that the steel tubes and pins in the middle of the truss are lighter (smaller) than the steel tubes and pins on each end of the Open-Web truss… so, if you cut a truss at any given point, alter the bearing conditions, or stiffen a truss, it will not carry the load the way in which it was designed, which may lead to failure. Real Life Failed Fixes: Improper tension splice connection detailing resulting in bottom chord failure. One simple example of a field alteration that seems harmless but can lead to serious problems is the trimming of an Open-Web tail or top chord.  This can seriously affect the strength of a truss, even if trimming only a half inch of wood material.     [caption id="attachment_439" align="alignright" width="300"] Splice of topchord without factory drilled/routed MSR chord material (gaps/poor craftsmanship along with improper materiall).[/caption] People sometimes ask me to explain how a 2x4 flat chord of a Red-L™ Open-Web truss can span over 30', and my short answer is, "It can't".  It's not possible to span 30', the 2x4 only spans from truss pin to truss pin (approximately 2 to 3 ft.').  That is the beauty of an Open-Web truss, the components have to work together or the member is compromised.  One missing pin, one bent steel web, one split or damaged chord could create a system that is no longer a truss but a 2x4 spanning 30'.   [caption id="attachment_436" align="alignleft" width="300"] This truss was improperly altered by cutting the member to avoid duct and which has turned it into a 2x4 spanning 30’.[/caption] To the left is a recent picture showing the end result of an unknown party that took the liberty to shorten a truss span and get creative with the use of a typical solid sawn joist hanger.  This resulted in a 2x4 spanning 30'.  This system is waiting for a solution to prevent a future collapse.  This entire roof will (most likely) need to be replaced due to the overloading of several truss components.  This situation could have been avoided very easily if RedBuilt had been called in the beginning.   At RedBuilt™, we strive to take care of our customers and provide the products and services to help build their future.  As such, we offer a limited lifetime warranty and the services necessary to maintain them.  So, when you see damage or wish to modify RedBuilt™ products, please contact your Technical Representative as soon as possible.   We look forward to working with you to find the best solution to your problem.  


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