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What Is a Lally Column?


Jack Post, Adjustable Steel Column, Lally Column

Adjustable Steel Column

© Tiger Brand
Definition: In popular usage and typically used incorrectly, a lally column, often called an adjustable steel column, is a telescoping steel tube that adjusts upward or downward to temporarily support a weight from above.

One example of a lally column's usage: when a builder or remodeler removes an interior, load-bearing wall, he will insert a lally column in place of the wall to keep the house structurally sound. This lally column will later be removed when the wall is rebuilt or other bracing is installed (such as a beam).


  • A true lally column, according to David Brindle at Dean Column Co., is "actually a concrete filled steel column for permanent structural support. It was invented in the late 1800's by John Lally in Waltham MA."
  • Lally columns are meant to be temporary.
  • However, this doesn't mean that some homeowners and remodelers don't use these jack posts or lally columns on a permanent basis.
  • Lally columns are often used in crawlspaces or basements to support sagging floor joists.
  • Lally columns cannot be used for jacking up any kind of weight. A jack should be used to elevate the item, after which the steel column is inserted.
  • The entire spectrum of lally columns ranges from about 12 inches to 12 feet tall.
  • Within each class of adjustable steel column, there is an adjustment range. A typical adjustment range may be 7 ft 0 in to 7 ft 4 in (84"-88").
  • Steel plates at the top and bottom of each steel column are necessary to prevent the cylindrical ends of the columns from biting into the wood.
  • The shorter lally columns have a greater maximum weight rating - up to 18,000 pounds.
  • While lally columns can be rented by the day, they are so inexpensive that it is usually more cost effective to purchase them.
Also Known As: Adjustable Steel Column, Jack Post
Common Misspellings: lollie column, lolly column
After he removed the exterior wall, Jim put in a series of lally columns to keep that side of the house structurally sound until he could rebuild the wall.

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