Understanding Steel Building Wind & Snow Load Requirements

Sure, it’s obvious that your steel building will be heavy. In fact, the standard dead load of the building itself is 2.5 pounds per square foot. But remember that the weight is not evenly distributed throughout that square footage, rather it is directed into very specific points of contact where the structural beams, attach to anchor bolts and ultimately meet the foundation. So your 40′ x 60′ steel building, let’s say, has 3 tons of weight focused on these footings. Not a small task. Your concrete contractor supplying the foundation slab or piers must be knowledgeable about the loads exacted by your specific steel building snow load, its intended use, and location. Anchor bolt settings and reactions will be supplied from the manufacturer, usually within 2-3 weeks of your building order.

Of course, that’s only the dead load.

Now let’s bring in other factors. Live loads are the forces applied to the building. Depending on the use of your building, you will have people in and out of your building, shelving, furniture, tools, machinery, products, etc. Whatever it is that is applying force to the structure of your building qualifies as the live load. In general, the industry assumes 20 pounds per square foot. It’s good to know that the industry has exacted safety standards to build into the structure, frames, and walls, and reactions to these loads are factored into the anchor bolt plans and foundation work.

Let us not forget about the weather

Snow load and Wind Speed loads have their own category aside from dead and live loads. Snow loads and wind speed load requirements are determined by your ZIP code and also built into the pricing and design software utilized by your metal building broker. Always check with your local building department for specific code requirements so that you are knowledgeable when placing your steel building order. “Some brokers are transparent in their pricing to well-inform the public of what to expect. They will note the snow and wind speed codes which the pricing posted on the website reflects,” says John Barber, president of Factory Steel Overstock. If it’s not clear which codes are being priced, be prepared to supply your ZIP code when requesting a formal bid.

Again, snow loads are their own load specification because of the nature of precipitation. Snow can drift causing depths heavier in some locations on the roof than in others. Wind load, similarly, is determined by patterns of climate. It differs in that it will affect different portions of the building not limited to only the roof. The wind’s effects on your steel building structure will vary depending on your design. The height of your building, the size and number of large framed openings and even the location of those openings will be factored in during the pre-engineering design process, also given by your specific wind load requirements determined by codes associated with your ZIP. From zero mph to over 150 mph winds, you want to be sure that your building is built to last.

Finally, you metal building broker will ask whether your building department has specified Exposure B or C for your building site. It depends upon the natural windbreaks provided by your surroundings. Exposure C will be your request if your steel building will be erected in a wide open area subject to wind.

Understanding loads on your steel building are important to understand as pricing revolves heavily upon them. In addition, you will want to be able to make educated decisions when it comes time to make foundation choices. Your building is only as durable as the foundation upon which it stands.