Expansion and Repair on Existing Metal Buildings

Part 2 

Part 1 of this topic can be found here: Customizing Your Pre-Engineered Metal Building 

It’s no secret that steel buildings are known for their durability. The lifetime of pre-engineered metal structures can last multi-generations and throughout that time, facility expansion may become an important component for the success and future of the business.

Pre-engineered steel buildings are apt for expansion and customization when done correctly by an experienced construction partner. There are several different ways to expand an existing metal structure and before selecting the method of expansion, it's imperative to understand the constraints of the property, the current structure, and current codes for expansion.

Once expansion has been validated as possible on the property, the next step is to determine which method best meets the goals for the building expansion. Growth by expanding post-and-beam end walls, expansion wall, structural add-on, and second-story additions are some ways to add onto an existing metal building:

• Post-and-beam end walls: This method adds frames to the pre-fabricated steel buildings' end walls. Meaning, the building is expanding in footprint in width and/or length. Typically, this solution is a fairly economical option as they don't have to bear as much weight as other options. Some challenges, however, include that this method does require some bracing and because of that, overhead doors and large openings need to be identified during manufacturing – relocating those openings during a remodel is not possible in bearing end walls.
• Expansion walls: This method is preferred by many contractors as expansion walls are designed to accommodate adding on to your building in the future. Expandable walls are more expensive than post-and-beam end walls as they can carry the weight of half the bay now and half of the future bay if expansion is needed. This method requires ensuring the original building has the appropriate resistant frame for expansion. If not, purlins and grits will need to be shored up, other grits will need to be removed, and the new resistant connections will need to be erected before the addition of bays or new end walls can be executed.
• Structural add-on: This method is simple and cost-effective. A structural add-on is where a new structure is built alongside the existing building and two gabled roofs (new and old) share a common wall. This expansion method, however, comes with risk. The shared common wall is susceptible to overloading in adverse weather – specifically winter weather conditions. 
• Second-story addition: This method is highly desired in situations where the building is locked on all sides. Before landing on this method, be sure to confirm the original structure can support the additional load from the second-story addition. If the current structure isn't built to support the added weight, consider an outer vertical member where it can rest on the foundation of the facility. This will allow the second floor of the metal building to be supported by the new frame and the original structure remains "as-is".