A homeowner might start to worry about costly repairs if a home is suffering from structural problems such as sagging floors. These thoughts are understandable given the importance of a home’s foundation. For minor foundation issues, it is possible to install a few lally columns in crawl spaces and basements.
What is a Lally Column?
When performing major repairs such as wall remodeling or the installation of new windows and doors, Lally columns can be temporarily used to support extremely heavy structural weight.
Sometimes permanent lally columns can be installed to fix structural problems. Lally columns can often be left in place by local building codes.
A non-adjustable, steel column that is cut to size and filled in with concrete is the oldest type of lally column. The term now encompasses many other types of mobile steel columns such as teleposts and adjustable steel columns.
Two telescoping steel tubes inside adjustable columns can be used to support a beam or joist that is not supported.
This post is often mistakenly called a “lolly columns” because it was designed by John Lally, Waltham, Massachusetts in late 1800s to provide fireproof and insect-proof support for buildings at their lowest points. It was designed to be filled with concrete and used for structural support for loads of up to 44.600 pounds.
Permanent vs. Temporary Lally Columns
Lally columns are either temporary or permanent. Workers often use temporary columns to brace the floor joists above while removing walls. Sometimes permanent columns are used to support the structure in crawlspaces or basements under houses.
Lally Columns Adjustable Range
Lally columns are typically between 3 and 14 feet high. The column’s height determines how much weight it can support.
A 6-foot-long, 4-inch-diameter column can weigh up to 21300 pounds. The column’s weight rating drops to 10,200 pounds by increasing its length.
Non-Adjustable Lally columns
One type of lally column cannot be adjusted so the steel column must fit into the space.
These columns are typically made from 11 gauge steel and have a diameter of 4 inches. However, smaller diameters may be available. These columns can be used in a basement with drywall and wood or left open.
You can paint exposed columns. Many lally columns are in prime condition and ready to be painted.
How to Install a Lally column
These instructions assume that the adjustable steel lally column will be installed on a concrete floor footing, and underneath a load-carrying beam like laminated veneer lumber (LVL), beam.
Take a measurement of the space
The vertical distance to be covered is measured. Each lally column has an adjustment range that allows for the machine screw assembly to be adjusted. The typical adjustment range for the machine screw assembly is four inches. A lally column can span from 7′ 9 to 8′ 1. This is for support of a beam eight feet high. A column can be adjusted but you should minimize the height of the screw portions as it adversely affects its strength.
Install the Upper Plate
Attach the metal plate included to the underside the LVL beam. Because the bolts required to attach the plate are too large to crack the beam, pre-drill the holes in the LVL beam. Once you’ve determined the location of your metal plate, remove it.
Attach Plate to Lally Colum
Attach the metal plate to top of lally column
Raising the Lally Column
Turn the machine screw so that the column is approximately 1/2 inch shorter than the distance between the floor and the base of the load-carrying beam.
Move Column Into Place
Place the column. For placement instructions, consult the manufacturer’s instructions. Some adjustable lally columns can be placed with the machine screw at the top while others can be placed at the bottom.
Continue to Raise the Lally column
Turn the screw until your lally column is snug against the beam. It is important to secure the column in place, but not to raise the beam.
Take out the Lever
Slide the adjustment mechanism out of its place if it is removable. Keep it safe. For any adjustments, keep the lever close by.
Projects for Lally Columns
- To keep the house structurally sound, a contractor or builder will install a series lally columns to replace the wall. These columns will be removed later when the wall is rebuilt, or another type bracing (such as a beam) is installed.
- To correct sagging floors, short jack posts can be placed in crawlspaces or basements.
- Temporary projects which require quick and easy removal.
Lally Column Safety Measures
Lally columns, simple tubes of metal that are often installed incorrectly, can become very dangerous. If a lally column has been installed incorrectly, it can explode like a rocket when it is subject to the enormous weight of a housing structure.
- The majority of lally columns should not be used to jack up the item. To raise the item, a hydraulic or screw-house jack is used. Then the steel lally columns are inserted. Once the column has been installed, the column can be adjusted with the screw-jack portion to adjust the elevation.
- Columns are rated according to their verticality. A column that is not perfectly vertical can lead to serious injury or death. The weight of the columns above could cause them to tip over and force them out of their place. To ensure the column is vertically level, use a laser level. To ensure that the column is perfectly balanced, use a bubble level.
- To prevent the ends of the steel columns’ cylindrical ends from biting into wood, the columns must have steel plates at their top and bottom.
