METAL BUILDING 101
What we recommend for a building and how we design it depends upon what the building will be used for. An un-air-conditioned warehouse building can be a bare bones type of structure. An air-conditioned retail building, office or manufacturing facility will require different considerations. Some things that may affect our design approach are:
Will the building be air-conditioned? This is important for a couple of reasons:
- Corrosion protection. We highly recommend the use of G-90 galvanized secondary framing for most buildings in South Florida or the Caribbean. But if the building will be air-conditioned it may not be necessary.
- Insulation – What will the usage be? How much will electricity cost to air-condition the building? What U factor or R factor is required? Will the building be a LEED certified building?
- We can provide from R10 on up to R40 insulation in roof and wall systems.
- We have a lot of experience for cold storage warehouses. It is a niche market that we know well.
Where is the building located?
- Close to the ocean or in a corrosive environment, we recommend G-90 galvanized purlins and girts. Sometimes, we will recommend hot dip galvanized structural steel.
- Within 1,000 feet of the beach, over uninterrupted terrain requires different design criteria (exposure) for hurricane zones.
- Is seismic design a consideration? We can help with the correct building code.
Standing Seam or screw down roof?
- Screw down roof systems are less expensive but more prone to leaks as the building ages.
- Standing seam roof systems are superior for high performance buildings (offices, retail, air-conditioned buildings).
- We can provide a variety of beautiful exterior facades that are cost efficient. Think the look of pre-engineered metal buildings is too industrial? We can provide the cost benefits of pre-engineered construction with the architectural sizzle of a conventionally built building. Let us help you build a beautiful office or retail building.
- We like to provide KYNAR paint on roof and wall panels, especially for buildings with ultimate destination in South Florida or into the Caribbean.
- We can provide the standard polyester paint finish and are comfortable doing this.
- Roof systems can be supplied as bare galvalume. Galvalume will typically last 20 years before any type of corrosion is evident.
- It is possible to space columns and frames up to 60’-0” apart, however, the sweet spot for economic reasons is somewhere between 25’-0” and 29’-0”.
- Bay spacing typically depends upon the interior layout of the building. We try to bury frames and columns inside interior partition walls, or at minimum place them so they do not interfere with window and door openings or equipment placement.
- Expanding bay spacing can eliminate frames and may save money.
Clear span or interior columns?
- An important advantage of rigid frame and pre-engineered metal buildings is the large clear spans possible.
- The point at which the use of interior columns will save money over a clear span building is generally for a building that is 80’-0” in width. Below that width there is typically not any appreciable savings. But even above 80’-0” in width, the cost savings may be minimal because you have to excavate and pour additional foundations for the interior columns.
- Unless the building is 120’-0” in width, we do not recommend changing the usage of your building in order to save money by putting in interior columns. The value of a clear span building will typically be more than what you can save by using interior columns.
- Will there be any roof mounted equipment? We can design the building to meet any requirement, and can design stands and platforms for the equipment too.
- Suspended equipment inside the building? Tell us so we can design the roof to carry any collateral loads imposed by electrical, mechanical or refrigeration equipment.
Lateral bracing. All buildings require lateral bracing perpendicular to the direction the frames run.
- X-Rod bracing is less expensive but you may not be able to put all of the door and window openings that you require.
- Portal frame bracing is more expensive but it leaves the building side walls open for windows, doors and accessories.
- End wall bracing is required if the end walls are framed in typical post and beam type construction. We can get around this by providing a half load frame at slightly more cost. If you require a lot of door or window openings in the end walls we can provide a half load frame that will not require bracing.
Will the building be expandable in the future?
- If so, we need to know this so we can provide an expandable end wall frame.
- This could add a couple of thousand dollars to the building cost but save a lot more than that when the building is expanded in the future.
Long life fastener / stainless steel cap screws.
- Important in the corrosive environments of South Florida and the Caribbean.
Will the building have a mezzanine?
- CSS / APTEC have a huge advantage in that we typically design our own mezzanines independent of the pre-engineered metal building manufacturers. We can almost always save money by doing this.
- We provide the stairs as part of our mezzanine design.
- Will there be any masonry walls? If so, designing the walls to carry the mezzanine will save money.
Will the building have an overhead crane?
- You tell us what you require, we can design the building to carry a crane and provide the crane too.