Concrete Foundations and Metal Buildings

by Mark Robins | 2 September 2019 12:00 am

Offering a complete, bolt-together package, with little to no cutting or welding of structural members, a metal building can be constructed quickly and efficiently. The efficiencies do not stop there. Based on a designed systems approach using cold-formed, secondary framing members along with the specially designed tapered columns and rafters, only the right amount of steel is used making for a very efficient use of this raw material. This article will explore every contractor’s worst nightmare, but hopefully shed some light on how to avoid it.

The concrete foundation is one of the first steps in every metal building project. Whether that means piers only, perimeter beams with enlarged footings, a full monolithic slab, or more complicated multi-pour foundations, this important phase of construction will set the pace for all trades that follow. Concrete foundations and anchor bolts, which are so closely related to one another that we’ll lump them together for this discussion, lie on the critical path to getting a project underway and ultimately done on time.

Speed is a benefit of using a metal building and there is a constant push to get anchor bolt drawings from the metal building manufacturers as fast as possible. Often times a preliminary bolt pattern and estimated column base reactions can be provided as soon as a designed quote is provided. Thesepreliminary values are almost always stamped “Not For Construction,” and with good reason.These preliminary values have not been sealed by a licensed engineer, but, aside from that very important point, there may still be some fine tuning needed to the design that will potentially alter these values. Until the final seal is attached to the building erection drawings, there is risk involved in using those values to design and install a foundation.

Metal building manufacturers employ licensed engineers, but these engineers are not the Engineer of Record for the overall construction project, nor do they design the foundation. A metal building is an engineered product, and the engineers that design and ultimately stamp the drawings for those products are limited to the oversight of those products only. This manufactured product does, however, directly affect the design of the foundation. Good communication amongst all parties involved is paramount.

Anyone who has been in the industry for any length of time knows it is not uncommon for issues to arise once building materials show up and installation begins. When those issues are related to the concrete dimensions not matching up across the foundation drawings, the metal building drawings and the physical concrete that is in the ground, those problems stop everything. Sometimes it is an easy thing to get hung up on the blame game, but it really is in everyone’s best interest to work together to find a solution as quick as possible.

Avoid these Problems

• Do not use preliminary anchor bolt drawings provided by a metal building manufacturer to design a foundation. Reserve this information for estimating and budgeting purposes only.

• Always reconcile the erection drawings provided by a building supplier against the drawings provided by a foundation engineer before proceeding with any field work.

• Check foundation dimensions and anchor bolt locations against drawings as often as you can, such as when concrete forms are installed, and when anchor rods are initially positioned. Spot check as the concrete pours and do another thorough check after the concrete pours, but long before the steel arrives. Always use a competent member of your team to oversee these activities.

• For the more complex or high-profile projects, hire a third-party surveyor to double check the work once the concrete is poured.

• Ensure embedded bolts and rods are set vertical and at the correct embedment depth, taking into account grout thickness, if specified. There are typically remedies in instances where something is off, some easier to swallow than others.

• Build templates for each base plate location. Simple plywood templates can be easily made on site and then discarded later.

• Be proactive. Time is a limited commodity. Some problems can’t be avoided, so uncovering problems earlier is always better than later.

• Communication is key. Addendums and change orders are a given. Be diligent. Changes have to be documented and made available to all of the parties involved.

Brian Shelton is marketing manager at Chief Buildings, Grand Island, Neb. For more information, visit www.chiefbuildings.com[1] or call (800) 845-1767.

Source URL: https://www.metalconstructionnews.com/articles/concrete-foundations-and-metal-buildings/

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