Adjustable Steel Columns
A few facts about adjustable steel columns:
- They are usually found in basements.
- In some parts of North America, adjustable steel columns are called lally columns, although this term sometimes applies to columns that are concrete-filled and non-adjustable.
- They can be manufactured as multi-part assembles, sometimes called telescopic steel columns, or as single-piece columns.
The following are potentially defective conditions:
- The post is less than 3 inches in diameter. According to the 2012 International Residential Code (IRC), Section R407.3, columns (including adjustable steel columns)…
“shall not be less than 3-inch diameter standard pipe.”
Poles smaller than 3 inches violate the IRC, although they are not necessarily defective. A 2½-inch post may be adequate to support the load above it, while a 4-inch post can buckle if the load exceeds the structural capacity of the post. Structural engineers — not inspectors — decide whether adjustable steel posts are of adequate size.
- The post is not protected by rust-inhibitive paint. The IRC Section R407.2 states:
“All surfaces (inside and outside) of steel columns shall be given a shop coat of rust-inhibitive paint, except for corrosion-resistant steel and steel treated with coatings to provide corrosion resistance.”
Inspectors will not be able to identify paint as rust-inhibitive. In dry climates where rust is not as much of a problem, rust-inhibitive paint may not be necessary. Visible signs of rust constitute a potential defect.
- The post is not straight. According to some sources, the maximum lateral displacement between the top and bottom of the post should not exceed 1 inch. However, tolerable lateral displacement is affected by many factors, such as the height and diameter of the post. The post should also not bend at its mid-point. Bending is an indication that the column cannot bear the weight of the house.
- The column is not mechanically connected to the floor. An inspector may not be able to confirm whether a connection between the post and the floor exists if this connection has been covered by concrete.
- The column is not connected to the beam. The post should be mechanically connected to the beam above to provide additional resistance against lateral displacement.
- More than 3 inches of the screw thread are exposed.
- There are cracks in upstairs walls. This condition may indicate a failure of the columns.