Specifying Metal Building Systems

by Paul Deffenbaugh | June 1, 2022 12:00 am

 

Even though there has been a significant increase in sophistication and complication of metal building systems, still they are often misunderstood by the design community and dismissed or ignored. Part of the reason is lack of familiarity. As Matt Stone, vice president of sales for Schulte Building Systems, Hockley, Texas, says, “Architects do not have curriculum related to metal buildings in their degree programs. Methods and materials are the closest subject.”

Consequently, learning to specify a metal building system requires on-the-job training, which can be fraught. Unnecessary difficulties and errors creep into the process because of incomplete knowledge or a lack of experience.

Know the System

The start of the research begins with understanding the manufacturers and what they offer. “Don’t assume that all manufacturers offer the same system,” says David Dowell, AIA, partner at el dorado Inc., Kansas City, Mo. “In our experience, I would say each company has evolved their system in their own particular way and you have to get to know the system. You really have to get to know it thoroughly, because it’s not like you build a wall system and then a roof system. It’s a whole building system and you really have to understand what are the components of their system. Where are they inflexible? Where can they be flexible? What is required to keep their system intact because you’re generally buying a warrantied system. Depending on what you want out of it, the more you know the system, the more you can play with it and manipulate it.”

Not only can there be confusion about the types of buildings offered by different manufacturers, there are also differences in their approaches. Tim Wybenga is principal at Portland, Ore.-based TVA Architects. “Because many architects spend much of their time in non-metal building construction, there’s a good deal of mystery about what services the metal building manufacturers provide and how the design and engineering process for these buildings differs from more familiar building types.”

That lack of experience translates into a difficulty in communication and understanding. Sean Slattery, AIA, LEED AP, is also a partner at el dorado. “[Knowing the differences in manufacturers] gives you a head start when you engage their engineers and the shop drawing process,” he says. “It kind of gives you a little street cred with them when you’re using their vocabulary and they can tell you’ve spent some time with it.”

His solution is to really dig into the manufacturer’s catalog and familiarize himself with the system. “If you really show that you’ve given their system the time and that you’re respecting it,” he says, “with all of the R&D they’ve already put into it, you’re not trying to reinvent their wheel for them. Frankly, it gives us a running start at coming up with a project that we all could be proud of. When we understand their system right off the bat, and know something like the 12-inch-deep girt only comes in 18-foot lengths, whereas the 14-inch one comes in this length, it can really help get a tight set of shop drawings quicker from their end.”

There is an additional advantage to familiarization with the catalogs. “If you approach them with a set of informed questions rather than open-ended questions, you can really dig in quickly, and I’ve found their engineers are actually excited to do something a little different, you know rather than just repeating a project over and over again.”

Why Customize?

Doing something a little different doesn’t necessarily mean customizing a metal building system. Tucker Cope, PE, is president of C. Tucker Cope & Associates, a design-build contractor that offers metal building systems. “Customizing costs time and money,” he says. “When an architect forces customization on the metal building, you take away the advantages of using a metal building. We try to keep customization to a minimum or do hybrid structures.”

He offers the example of adding hips and valleys to a roof system for metal buildings. “Hips and valleys are great on your house,” he says, “but not so much on a metal building because there’s no substrate underneath the standing seam roof.”

Dowell agrees about customization. “When you ask a metal building system to do something that that particular system isn’t really good at, it can get hairy pretty quickly,” he says.

Not surprisingly, metal building system manufacturers would prefer to avoid customization because it slows their process and opens up other issues. “More complicated cladding and/or structure requirements always lead to more time required,” says Stone.

There is a middle ground between customization and an off-the-shelf product that often includes a hybrid system, and some architects have found ways to push the limits of the metal building system design. Wybenga is one of them. “We are generally pushing the limits of customization possible with metal buildings, and it’s really important to find a trade partner that is interested in collaborating on that kind of thing.”

More on the importance of collaboration and a team approach in a moment, but a caution first about customization beyond just time and cost. Using a metal building system, many architects are able to achieve sophisticated, exciting designs that serve their clients well, including saving money. But trying to do so without a full understanding of the constraints of the system can lead to unintended consequences such as a warranty violation.

“You have to really under understand how the warranties work,” says Dowell. “You might think supplementing a building system wouldn’t be a big deal, but sometimes if you put a screw in an existing system, you void the warranty. You have to know where the warranty is voided in this manipulation of the system. And you would think a manufacturer would be able to come right out and tell you that, but the truth is sometimes they don’t know until you propose something.”

Work with the Team

Dowell and Slattery tend to work directly with the manufacturer, but many architects work through a metal building dealer or contractor. That company orders the building and provides engineering services. (Those services don’t mean there shouldn’t be a structural engineer of record for the project.) The company ordering the building may or may not erect the structure. It might subcontract that work to a steel erector.

“Dealers that know metal building systems can spot issues during the conceptual design process and head off costly design features by discussing these concerns with the architect,” says Larry Heckman, district manager, Chief Buildings, Grand Island, Neb. “In other words, it’s one thing to draw it, but another to build it.”

Cope agrees and says dividing up the labor allows individual companies to play to their specialty. “The manufacturers produce a product but they’re not architects or engineers,” he says. “They want to produce a product that a dealer orders. Architects really need to work with a dealer to resolve the problems on the front end so it can go through the ordering process cleanly. Metal building manufacturers will not take in a set of drawings and solve all the problems. When someone submits that quote, whoever signs the order takes all responsibility.”

“Most dealers are willing to give some design service to an architect to make sure the floor plans will work with bracing requirements, preliminary anchor bolt reactions, and frame configurations,” says Dan Halme, owner, Halme Builders, an AC478 accredited general contracting company in Davenport, Wash. “General contractors with metal building dealerships are the best relationship for an architect. They are invested in finding solutions that not only work for the metal building part of the equation, but they make sure that the system works well with all the other potential obstructions and considerations the architect might need. This is especially true if the architect is designing hybrid structures that use other component types that manufacturers and suppliers do not have experience with.”

How can things go wrong? According to Cope, “Where people get a bad taste about the industry is when a GC that specializes in hospitals, hotels, and stores gets a metal building project. They get drawings from an architect for the metal building, they ship them to the manufacturer and they get a price. They have no idea what they’re looking at and then they hire an erector to put the building up. Stuff starts getting screwed up on-site and they go, ‘we got the price from the manufacturer’ and the manufacturer says, ‘but did you read your contract. It says, we didn’t do all this stuff, and you have to clarify all this stuff. The GC will never do another metal building. That’s what gives the industry a bad reputation.”

To address structural issues that aren’t related to the metal building system, Wybenga uses a “direct-to-architect structural engineering consultant for items that are not specifically part of the metal building team’s responsibilities. It’s easy to get into a ‘chicken and egg’ situation with these scopes with things like the engineering for grade beams and floor slabs in particular.”

For manufacturers who have affiliated builders, there is another advantage for architects working with metal building contractors. “If you have the opportunity to work with a contractor and have them lean towards one system or another,” says Dowell, “I would say it has almost a hundred percent chance of influencing a system.”

Common Errors

Familiarizing yourself with the specific elements of different manufacturer systems and putting together a team that handles all the services needing with clearly defines responsibilities goes a long way to heading off any issues that can arise on a metal building project.

But there are problems that might occur that architects should keep their eyes open. Heckman provides a list of mistakes he often sees from the manufacturers’ point of view:

• Brands that are no longer in business or have been acquired by a parent company, leaving a limited list of approved manufactures for the general contracting community to solicit from.
• Conflicting and confusing information.
• Loads and codes that are different from what was listed on the drawings.
  • Hot-dip galvanizing versus G30 or G90 primary/secondary steel.
  • Insulation thickness may be given, but U-values need to be confirmed. Are these installed U-values?
  • Not specifying the collateral load requirements. 95% of the time this information is never presented in the specification and/or drawings.
  • Deflections for purlins, girts, rafters, columns/posts, panels, etc.
  • Weathertightness warranties with limited or no-dollar limit
• Selection of paint finishes. Which is more critical? Warranty duration or paint type? SMP has come a long way and now offers warranty durations that rival PVDF.

Just specifying a metal building system doesn’t complete the design process, of course. “Even though the prefabricated buildings have a sort of turnkey aspect to them once you get through the shop drawing process,” says Slattery, “the thorough coordination of all the other scopes is no different than any other project. So, the lighting and the MEP systems and everything like that is just as rigorous of a process.”

As an engineer, Cope identifies very specific issues he sees with drawings from architects and structural engineers. Perhaps the most common is getting the end wall set back correct. “Architects and structural engineers never get metal building end wall setbacks correct,” he says. “They always specify from the center of a column. On a typical metal building, you have a base plate and architects always want to go from the center of that base plate and a metal building typically is tapered columns so that center varies as the column height goes up.”

Adding to that confusion is every manufacturer has an end wall setback that is a little different. Cope’s solution for architects is, “You have to show where the first frame line is, but you can’t really give it a dimension. End walls are very confusing to architects, and the best solution is don’t try to give it dimensions, just show it.”

In his experience, Cope sees a couple of other issues that arise from drawings. Architects are unfamiliar with the base spacing for particular brands and specify spacings that won’t work, which means you have to use non-standard roof purlins and lose the cost savings. Also, poor coordination of material thicknesses and insulation values.

He recommends that the metal building system be bid out ahead of the main structure, which allows the metal building to get designed and be part of the final design of the project.

A final word of caution from Halme. “An architect should be aware of the effects of using boilerplate specs and references,” he says. “Many boilerplate specifications include outdated references to programs and testing requirements that no longer exist. New programs, accreditations and quality assurances are often lost in old boilerplates as well.”

Source URL: https://www.metalarchitecture.com/articles/specifying-metal-building-systems/

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