So what comes to your mind when you hear one or more of the following words?
- lally / lally column
- adjustable support columns
- steel columns
- lolly / lollie column
- jack posts
- floor jacks
- screw jacks
- structural columns & piers
- teleposts
- red-I-Posts
Although it can be confusing, they all describe a type of weight bearing support column that is permanent or temporary in nature.
They are usually a round, steel-walled structural column that is used to support weight-bearing beams carrying significant weight/load.
Lally columns are usually deployed under long stretching beams to prevent sagging.
I needed to support about 21 feet so I ended up using four adjustable jacks to be placed approximately 6 feet apart to support a tripled 2×12 support beam.
THREE DIFFERENT TYPES OF “LALLY” COLUMNS
LALLY COLUMN
- Also referred to as a lally, steel column, lolly, lollie column, fixed length column or structural columns & piers
- A lally column is a non-adjustable, concrete filled support column. Due to its monolithic design, it is the strongest out of all three.
- It can be used in a situation that is permanent or temporary but due to its fixed size, it would be more suitable in a permanent support projects.
- If a lally column is used as a permanent support, it has to be meet certain requirements such as tubing thickness and filling it with concrete. You need to check with your local building inspector.
- A concrete filled lally column can be cut. The steel can be cut with a special tool (“lally column cutter), a circular saw with an abrasive blade or a Sawzall with an abrasive carbide blade (not as accurate as the circular saw). In all cases, The concrete core is snapped with a hammer blow.
- A beam plate or saddle plate is required at the top to secure the column to a support frame
- An adjustable base set (check with your bldg inspector) or end plate (a.k.a. springfield plate) is required at the bottom to eliminate lateral movement.
MONO POST
- Also referred to as an adjustable building support column, steel column, structural columns & piers, teleposts or red-I-Posts
- Designed to be a permanent building column but check with your local building department
- Fully assembled, self-contained unit
- Usually adjustable in lengths up to 12 feet
- Poured concrete or spot weld locks post adjustment permanently
- According to ICC-ES reg, the adjustment nut and screw must be placed at the footer
- A beam plate or saddle plate is required at the top to secure the column to a support frame
- An adjustable base set (check with your bldg inspector) or end plate (a.k.a. springfield plate) is required at the bottom to eliminate lateral movement.
FLOOR JACKS
- Also referred to as jack posts, floor jacks or screw jacks
- Designed to be a temporary support column
- Needs to be assembled
- Fully adjustable with double carriage nut and bolt for added strength and safety.Usually adjustable in lengths up to 12 feet
- Weakest out of all support column types. It loses a percentage of load rating due to localized loading
- To reduce the chance of crushing the lumber or breaking through the concrete floor, a minimum of 1/2″ steel plate (3/4″ or 1″ is better) should be placed the under the ceiling joist (on top of the post) and on top of a 6×6 or 8×8 post (on the bottom of the post or bottle jacks).
LOAD RATING
Check with the manufacturer for specific load ratings as they are dependent on such factors as steel tube thickness, steel grade, screw height, etc. (here is a sample load rating table from Lally Corp)
FLOOR JACKS FOR REPLACING ROTTED RIM JOIST AND SILL PLATES
What I wanted was a strong adjustable column (i.e. thick tubing) with minimal to no lateral movement to ensure that the support will stay in place while I worked. There are lots of cheap brands choose from but keep in mind, they are cheap for a reason (like having thin tubing or the inner tubing with excess sleeve gaps).
I ultimately chose the Tiger Brand because they have extensive information available at their website.
Also, floor jacks come in variety of heights so make sure to factor the height of ALL components (i.e. thickness of the metal plate, height of the bottle jack) before buying them.
WHICH SIDE UP?
Most, if not all manufacturers state that it does not matter if the screw side is up or down when using floor jacks (when using mono posts, adjustment nut and screw must be at the footing).
However, Inspectapedia.com had this to say (actual link is here)
…Some installers place screw jacks or teleposts with the screw down against the concrete floor or pier top.
That allows the larger-diameter post “bottom” to be placed up against a steel plate and against the underside of the beam. This “upside down” installation reduces the chances of bending the steel supporting plate and it also places the thick steel screw down on the (often wet) basement or crawl space floor. The thicker steel screw is slower to rust through to the point of collapse than is the thin-walled hollow steel pipe that forms the body of most teleposts.
In my limited personal experience, I found it to be much easier if I had the screw side “up” at the top and here are the two reasons why:
- Center of gravity – With the screw side down, all that steel tube mass is now up high, making it much more difficult to maneuver to plumb the darn thing
- Screw turning – I found that it was physically easier on me to be standing up and turning the screw, rather than being hunched over (talk about a lower back killer!)
LESSONS LEARNED WHEN INSTALLING LALLY COLUMNS / FLOOR JACKS
- Support column must be truly vertical. That means taking two plumb measurements with a 6 ft level, 90 degrees apart. Skewed support columns have increased likelihood of “kicking out”
- Use at least 1/2″ thick (or thicker available) at the base and top to spread the load.
- Duct tape works wonderfully when holding top steel plates in place
- Make sure to label the existing height of the ceiling joists BEFORE lifting them
- Take your time when lifting. A week or more is not unheard of when lifting 1″ or more in height
- Bottle (hydraulic) jacks and floor jacks are NOT THAT HARD to turn. Take quarter turns on each jacks and listen for the telltale pops and cracks
- WEAR A HARD HAT!!!!
BUY OR RENT?
I initially considered renting these floor jacks but most rental places asked too much money.
For example, Fusco’s Rental in NJ wanted $25 per day for an 8 ft long floor jacks columns (or $100 each for a week). Since I planned on incrementally lifting the floor over a period of several weeks, I did not want to spend that kind of money.
In comparison, Home Depot sold Tiger Brand Super “S” 8 ft. 4 in. Jack Post for $46.87 each so I decided to buy instead of renting them.
Well, I hope you found this article to be useful for your DIY project and sign up for my newsletter. The signup form is found on the upper right hand corner of your screen.
Thanks and good luck!
REFERENCES LINKS
- Retrofitting a Lally Column – Mike DeBlasio (PDF file from JLC Online)
- Lally Colums at About.com ( http://homerenovations.about.com/od/toolsbuildingmaterials/g/LallyColumn.htm )
- Tiger Brand Jack Posts (link)
- Installing Lally Columns ( http://www.kwaree.com/blog/2006/09/05/installing-lally-columns-and-footings-for-girder-beam/ )
- Steel Tube Institute
Jkae
Friday 7th of November 2014
I'm curious - you used bottle jacks under your floor jacks on the rim joist project. Is it possible to raise enough using the threaded adjustment in the floor jack itself?
kevin
Saturday 27th of December 2014
@jkae
You would need to contact the manufacturers for that question but I used hydraulic bottle jacks because they are much easier to lift
Brenda
Tuesday 1st of October 2013
Once the screw jacks are in place, what is the issue with leaving them there permantly? As a Realtor, I see them in countless properties, and the home inspectors always point out that they are a temporary fix, and should be replaced with the permanent ones.
kevin
Wednesday 16th of October 2013
@Brenda-
I could not find any specific performance data on permanent vs. temporary support jacks, but my common-sense guess is that temporary jacks are labeled as such because they consist of hollow steel tubes which I would think is considerably less sturdy than a concrete-filled monotube.
I believe certain localities do allow temporary jacks as long as the threaded portion is either welded, cross-threaded or buried in concrete base.
Alase
Thursday 29th of November 2012
I need adjustable support for granite kitchen sink. Please advice including pricing.
kevin
Thursday 17th of January 2013
I am not a retailer.
You would need to take into consideration:
1. size of your floor joists and spans 2. approximate weight of the granite counter
good luck
David
Friday 5th of October 2012
This is a very good article. Most people have no idea about the lally column. You can find more info on lally columns at our website www.DeanColumn.com. Great work.
John Lally Column History
Thursday 16th of August 2012
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