Steel Building Columns – Tapered vs Straight

steel building tapered column illustration

Steel Building Columns - Tapered vs Straight

A common feature of any pre-engineered steel building is utilizing tapered columns and rafters.  This allows the engineers to design the main frame members that support your building with a reduction of steel while still maintaining the structural integrity to meet the design criteria.  Since we get quite a few questions about dealing with the columns when a customer wants to finish and interior, we thought a couple of illustrations might help explain this part of a steel building.
Gable main frame illustration

Rigid Clearspan Tapered Columns

steel building tapered column illustration

Rigid Clearspan Tapered Column

The majority of pre-engineered steel buildings utilize columns and rafters that feature a tapered design.  From the illustrations you can see that the I-beam column is smaller at the base and grows wider as it reaches the connection point for the rafter.  This happens to be the most economical design.

If your plans don't call for any interior build out, the tapered column can yield the most floor space in a clear span design.

steel building tapered column stud wall illustration

Tapered Column - wood stud framing

If you are planning to do any build out for the interior of your building, the tapered design is still a great option.  For instance, if you have a 20' building but only need to build out office space that has a 10' ceiling, you will box out the column to the point at which the ceiling starts.  This typically results in a wall with less intrusion into your room.
steel building tapered column boxed out illustration

Tapered Column - Boxed out interior finish

Rigid Clearspan Straight Columns

steel building column straight illustration

Rigid Clearspan Straight Column

While the majority of pre-engineered steel buildings utilize columns and rafters that feature a tapered design, there may be a need that dictates a straight column.  One of the most common uses is for a monorail or under-hung crane system

Straight columns tend to be the same width from top to bottom as the widest point of a tapered column.  For certain interior build outs, you can see why you might want to go with a tapered column from the tapered illustrations above.

From the straight column illustrations you can see that the I-beam column is the same size from the rafter connection point (called the haunch) down to the floor base plate.  Many people assume that the column will be an average of the width on a tapered column, but that is rarely (if ever) the case.

steel building column straight with stud framing illustration

Straight Column - wood stud framing

In this illustration with straight columns, you can see that the interior build out results in more intrusion into the finished area than that of the tapered column.  Depending on the actual dimensions of the columns and the height of the ceiling, the difference could be up to 12" or more.  Not only does this take up more space, but in the pre-engineered building industry, more steel equates to more money for your building.
steel building straight column boxed out illustration

Straight Column - Boxed out interior finish

Part of the reason we like to talk to our customers is to understand your needs and help you value engineer the building so that you get the most for your money.  There are many options that are available when it comes to the design of a pre-engineered steel building.  From basic steel building information to steel building bracing, building types and so much more.  Give us a call today to see what we can do for you.
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