Adjustable “split” jack posts or “split” steel columns are improperly used in many homes in New York and are a structural defect. When any of these split type or telescopic adjustable post or columns are installed with the intention of permanent use for the support of main beams in homes it is an improper and unsafe application for which they were not designed. All “split type” adjustable posts are for temporary use only.
What I am addressing in this article is the “split” type hollow steel posts or columns; where the steel column is two or more pieces that telescope, one fits inside the other and they are pined or bolted together. It’s confusing because they go by many names, most of which are used interchangeably to describe different types of split and non-split columns. There are many adjustable steel columns that are not split; they are a solid one piece steel tube with a threaded adjustable end. Many non-split adjustable posts are suitable for permanent use.
Adjustable “split” jack posts are also known as:
“Split posts or columns,” “steel posts or columns,” “split-pinned posts or columns,” “Lally columns,” “lolly columns,” “jack posts,” “jacks,” “screw jacks,” “adjustable floor jacks,” “floor jacks,” “house jacks,” “tele posts,” “sectional columns,” or “double-sectioned columns.”
Originally a lolly or Lally Column was a proprietary name for the concrete filled, solid steel column invented by John Lally. Many people feel that the term should only be spelled “Lally” and that it should only be applied to concrete filled steel columns. “ For more on the Lally Column see: John Lally History.”
So what makes up an adjustable “split” jack post?
They usually come in two (but sometimes more) hollow steel tube sections with a threaded adjustment rod at one end and two small steel bearing plates one for each end. The smaller diameter tube(s) fit into the larger diameter tube(s) lining up the holes for the rough length adjustment. The sections held in place with steel pins or bolts which pass through the holes of both tubes. Then the threaded end section is placed at the top or bottom and is screwed for fine tune adjustment of height with a steel bearing plate at top and bottom.
No “split” jack posts are manufactured for permanent use in the USA. All home inspectors and code enforcement personnel should deem the permanent use of split jack posts or telescoping adjustable columns as a structural and safety defect in any home in the USA. This is a defect because no split jack post or telescopic adjustable column has been evaluated by a U.S. evaluation firm and none of their manufacturers cite an engineering report to prove these columns’ ability to carry a specific load. Also, according to the International Residential Code (IRC), a steel column has to be at least 3 inches in diameter. All split jack posts or telescopic columns are less than 3 inches in diameter.
Dangers of long term use of split jack posts
Rust, catastrophic structural failure and collapse are the potential dangers of using split jack posts or telescopic columns. When used in long term or permanent use there is the potential for loss of life and property. Should a sudden column failure occur, as sometimes happens, it could start a chain reaction of catastrophic failure of the floor structure and partial building collapse. The thin metal hollow tubes of these columns are not designed to withstand long term exposure to moisture and heavy pressures.
These temporary supports in long term use most often fail due to rust deterioration. These hollow tubes, especially at the bases are prone to rust, often buried in concrete or resting on cement floors or footers in damp or wet basements or crawl spaces. They are typically thinner gauge steel and cheaper quality than solid steel columns designed for permanent use and vulnerable to rust.
Their intended purpose is easily mistaken. With these adjustable split jack posts so readily available at most do-it-yourself big box, and hardware stores, home owners or the typical handyman can easily miss their intended use is only for temporary supports. Some manufactures don’t help matters with advertising on the boxes with claims of “give[s] lifetime support” and “For Remodeling and Additions” and “Corrects Sagging Floors, Supports Basement Beams” etc.
“As a home inspector I have a personal responsibility and a duty to my client to report the improper use of split jack posts or telescopic steel columns.”
My Home Inspection Report description of this defect
“Observed split-pinned or telescopic jack post(s) /column(s) in a permanent use application. All “split” type jack posts or telescopic posts/columns are designed for temporary use only; I recommend and strongly urge, for improved safety and structural integrity reasons, that the improperly used split-pinned or telescopic adjustable post(s) /column(s), those which have been installed as permanent supports, be replaced with proper cement filled “Lally” columns or approved adjustable solid steel columns designed for permanent use; Additionally…
… it should be ensured that the new columns have appropriately sized footings under each column or beneath the floor under the column if the column base penetrates the concrete floor slab; In such case where the floor was poured around the column base we can’t see if a proper pier or footing was installed to support the column base. Also note that when improper use of temporary split column(s) is present it could indicate the construction may not have been properly designed or that it may have been done without the proper permit or code enforcement.”
Split posts could indicate additional defects
If split or telescoping adjustable columns were installed when the home was built, it’s possible the builder may have cut corners else where such as the lack of sufficient foundation or load bearing support under the columns. So when I observe split jack posts being used in a permanent fashion I recommend they be replaced by a qualified contractor with proper supports and to ensure they are resting on proper footings. In some situations it may be wise to refer the matter to qualified structural engineer if additional issues are also involved.
Why is improper use of split jack posts so widespread?
With the with improper use of split jack posts or columns in so many homes, it does seem they were “allowed” practically speaking, at least locally and in many areas, for many years. It seems implausible that countless numbers of building code enforcement personal in different geographical areas could have missed such an easy to see defect in so many homes. I’m not certain why, if anyone knows and would like to weigh in on this it would be appreciated.
8 Reasons I blame for the widespread misuse of adjustable split posts
- Money. The telescopic or split adjustable posts or columns are less expensive.
- Time. They are faster to install.
- Laziness. They are easier to install.
- Availability. The telescopic or split adjustable columns are readily available at big box stores and small hardware stores nearly always as compared to the solid adjustable and Lally columns which are not as readily available, not stocked or by special order only.
- Lack of integrity, honesty and work ethic. I believe many builders have and do misuse split jack posts knowingly for a combination of the above four reasons, plus the next reason.
- No consequences. Many builders have gotten away with this, without consequence for the most part because code enforcement has overlooked this problem in many instances.
- Lack of Code enforcement. From my experience in the greater Syracuse area I know in many cases it seems the code enforcement personal are so over tasked, they simply cannot do all the inspections they should be doing. Only some things get inspected some of the time.
- Ignorance. I believe the average do-it-yourself homeowner and many handymen and beginning small time contractors simply are not aware of this problem. They see the improper use of the split posts all the time, thinking its normal use; and that’s what is available at the corner store. They don’t think twice about using them properly or not and most often split jack posts end up being used improperly.
Home buyers and the Home Inspection Report
In older homes there are usually many recommendations for components or items that can that can be improved, upgraded, replaced, or repaired for reason of improved safety or efficiency etc. However such recommendations are usually not required for the sale of the home or to be performed after the home is purchased. And such is life; many of these recommendations go unheeded, especially if they are expensive or complex.
The proper use of split jack posts
For all the bad press split jack posts have gotten here, they do have a good and purposeful function. The proper use of telescopic or split adjustable columns in construction is to adjust or level a structure before installing a permanent column; or, they may be used as temporary supports during the course of a building repair project but should be removed once the project is complete. You can actually rent split jack posts at some rental stores but it is usually cheaper to buy them if used for more than a day or two.
The picture to the left shows split jack posts being used temporarily for a sagging joist repair job until the permanent wood posts are in place. Now they can be easily removed. This is an example of proper use for split type jack posts.
Are the one-piece steel posts with the screw out bottoms safe for permanent installation? It seems that the screw out bottom, although set in concrete, would not be a proper support for a main beam. Would the post itself have to be set in the concrete to be sufficient? (I want to make sure my contractor did this properly!)
The screw out bottom placed in concrete is the preferred method of many builders and architects and should be perfectly safe as long as it is properly sized for the load. This is how I chose to install the support posts on an addition I’m currently building. The solid steel threaded rod is actually stronger than the larger hollow tube part of the post. Hope this helps.
The screw-out bottom placed IN or through concrete of the poured floor is done that way not for strength (below the concrete floor it’s likely also touching the very top of a strong footing) but to prevent tampering as the concrete of the poured floor after install on top of the footing inhibits turning of the screw. One other way is to place the screw at the top and when done turning, to finalize it the installer may purposely damage the threads to prevent tampering (thread damage inhibits turning of the screw.) Hope this detail helps, -TK
PS great article, in particular the rundown of the 8 reasons was easy to understand and well thought out. I wish everyone considering these at the Big Box stores would read this article first. I blame the sellers for this, as at my local Big Box store the descriptions of the telescopic posts has no indication “not for permanent use” or “doesn’t meet IRC requirements”. So unless the shopper goes online and drills down / opens the install guide .pdf they never find any mention of temporary use only, or that they are not designed as primary means of support, so most shoppers miss those facts. If one compares to the non-telescopic adjustable building columns, one would see these are IBC, IRC, ICC compliant right there in the description… compared to where the telescopic heavy duty steel floor jack description silently omits that line of the description and that’s the only clue. So if a shopper was only looking at the latter they wouldn’t know it. If one was only going by rated load being the same and price then you’d install the wrong one for sure as the telescopic jacks are cheaper.
Appreciate that insight Timothy.
Please help before I spend a lot of money once again. My stone fireplace and roof were not supported when my home was built 12 years ago. I have a 3/4 inch drop in my kitchen/great room floor which has caused cracked moldings, drooping molding on the kitchen/great room wall, walls and moldings.
What is the best and most permanent way to support this weight and raise my floor without causing damage to my stone fireplace and kitchen granite? Thank you gentlemen.
Hello Jan. This is an issue where you “really need” a full evaluation by a qualified, licensed, engineer or architect to determine why the foundation has settled and what your options are to stabilize or repair it. This is going to cost some money. Then you need a qualified contractor to follow through with the plan. That amount of settlement is more than normal and is certainly a concern you should address, sooner, rather than later. You can’t afford to skimp on cost here, a good repair now, will save you money and headaches down the road. Hope this helps.
I am looking for a house. I found one I like. During the inspection, I noticed the homeowner had three Jack posts set up in the basement holding up the joist. I questioned why the homeowner is using these. The husband installed these but he is deceased and the wife could not tell me why. They are using it as, a, permanent solution. I am trying to decide if this is a show stopper and not move ahead and buy the house. What is your opinion?
I have not seen the house so this is just some general information. In most situations I would say this should not be a reason to not buy a house. Normally posts are added to stiffen a section of floor or to correct a sagging section of floor. This is a good thing and not a bad thing. The most important things are to make sure the steel support posts are 1) structurally sound – not badly rusted – and 2) properly secured at top and bottom so they can not be knocked loose. Even if they are rusted and not secured properly or of the split pin type, it is not a big job, and not expensive to correct or replace them. Hope this helps.
I want to thank you for your response. According to my inspector, the I beams are structurally sound. He did mention the I-beam has a crown and if they are installed up side down could sit 1/2 low but from integrity point of view no structural Issue.
The house has two staircases going up to the second level. This is an unusual design in the subdivision. I am not sure if the weight of the second staircase was taken into account when the home was constructed. Two of the three Jack posts are located underneath the second staircase. My concern is when I remove the jack posts the floor will sag and I will have to install permanent posts which could be costly. That is the main reason why I am hesitant to buy the home.
Hello Julie, without seeing the house and what the situation is it is difficult to give any detailed opinion or recommendation. You did not mention if the jack posts were of the split type but I assume they are since you are talking about replacing them. So as I mentioned above, replacement of the jack posts should not be too expensive. I recommend that you get a qualified contractor to give you a cost estimate for the job, (which should not be much compared to total value or cost of the home) then you will know the cost involved and can make a decision.
Thanks for your help. I appreciate it.
This is a super helpful post and comment thread. Just wanted to say thanks!!
You are very welcome, happy to be helpful.
I actually live in the syracuse area and I’ve been at my girlfriends and realized their rental home has these jacks in their basement. I’ve noticed that their land lord is lazy and doesn’t do much to help improve the house or fix problems with it. So I was wondering if this is something that should be brought up to him or an inspector
Hi Shawn, the primary safety issue with these is rust, if they appear to be badly rusted there is potential for failure. But usually they rust little by little and the house will gradually settle very little by very little. However, yes you can bring it up to him or an inspector.
Are you able to bury the whole load bearing post inside a poured concrete foundation wall?
Why would you want to do that? Concrete has significantly more compressive strength that a post.
I agree most concrete walls would be more substantial than a steel column. However, sometimes a cement wall does not go all the way to the joist bottoms. Or for some reason they may want to leave it in place and pour a wall around it? – I’m not sure what the thinking is.
This is an excellent article. I learned a lot from reading it. Keep up the good work.
I am currently preparing to replace many split post jacks in my 147+ year old home. My basement is unfinished and has a dirt/ gravel floor. Most of the split post jacks are currently sitting on HUGE boulders that are deeply imbedded into the ground. The rocks have no evidence of cracking and appear to be bearing the weight of my old home very nicely. Would it be okay to place new adjustable solid column jack stands where the old split posts are? This would allow me to continue using these “colonial footers” which would save tons of $$. The other problem would be trying to remove these boulders from the ground that they used to originally support the home. I would rather not have to tackle that obstacle if it is avoidable.
Can i just use split floor jack small tube cause its to long for both tubes had to cut small diameter tube
I have a sagging sill beam ( 2×8’s sandwiched together) spanning about 10-12′ from a brick pier to the sill plate. The crawl space is about 24″ from joists to soil, give or take. A string line running that distance in my living room above shows a maximum deflection of 1-1/4″. I live in South Carolina, hours from the coast. The crawl space has a moisture barrier. It might be a good guess that the code may not be as strict as New York, but I don’t want to assume. I see what you’re saying here is the aim of utmost care. Would a run-of-the-mill telescoping post be okay for permanent use in this case? I would much rather use a non-telescoping adjustable, but I’m having trouble finding them. Of course I consider code-compliant footer and proper fastening. Would love to hear your thoughts. Good article.
I might also add to the previous post that there is a wall above the beam, but it is in the single-story sector of the house, dividing the living room-which is in the first stages of remodel-and the office, which is going to eventually undergo the same.
Hi Dwight, I sent you an email on this to explain in detail.
That may be possible depending on application. They make many different sizes of jack posts.
That will probably work, but it is highly recommended to confirm your upgrade plan with a local contractor or building inspector for confirmation.
I have an older house built in 1860. The living room floor is sagging about 2″ in the center. My basement has a dirt floor. I currently have one non-split screw post. It is set upon a concrete slab, probably 1’x1’x2″. This in not where the sagging occurs though. I would like to support the sagging part with a permanent solution. What type of footer is needed so the jack post doesn’t sink into the ground?
Thank you so much for the article. I am buying a 100 year old house with issues. Can you give me your thoughts on what kind of footing I should create in the dirt-floor cellar to properly hold up the IRC compliant solid adjustable collumns . Gravel? Poured in-plave concrete? Pre-formed cement block? Are there guidelines for size and thickness on these footers? The floor is uneven but very packed. Half the work would be done in a 2 foot high crawlspace. Thank you
Hi Luba, I am by no means an engineer or architect and am not a foundation contractor, so please check with your local code enforcement officials before you proceed on your own. The following information is not a suggestion for your job, but general information only. There are many variables involved in footer requirements for support columns, but the best footer is generally poured concrete of sufficient width and depth to support the load. The load and footer size and type for structural supports should be calculated by an engineer or architect to get it correct. This would be especially true if your were replacing a main support in the home or doing new construction. However if you are just adding some additional support to stiffen the floor or to prevent some long term settlement that has taken place in my opinion it is not as critical. Of course I have not seen your home, but if the soil is very well packed often a solid concrete block of 3″ x 9″ x 16″ is sufficient if it is leveled on solid hard packed soil. Many 100 year old and older homes I have seen were built with supports resting on stones no bigger than a standard cement block. Most of the poured concrete footers I have seen are about 12 inches deep and 2 feet by 2 feet in size. You can check with your local code enforcement, footers usually require rebar reinforcement of specified size and placement within the concrete footer. Additionally the footer should rest on undisturbed soil. Hope that helps.
I had inspection done on a 1963 house yesterday in Maine. The inspector noticed that the plates above and below the jackposts column had deflection , curling downwards on top plate and upwards on bottom plate. All 6 jackposts showed the same. the jackposts held up the main beam.
i would like to know more before I go through with house. is this not safe for house?
Sorry that is not enough information. What did your home inspector say? Were the plates steel or are you talking about wood blocks? If home inspector does not know then you should get it evaluated by a building contractor or structural engineer.
I read your column here and I understand why split jack posts may not be a permanent solution, but in your picture of using jack posts to temporarily raise a beam and then making a permanent support using wood posts, I have a hard time believing that the wood posts will not rot before a jack post rust.
Hi Ronald. I have seen many, many, many, rusted out hollow steel support posts in basements and most of those are resting on fairly dry concrete. I installed a couple for my neighbor earlier this year, and guess what, they are so poorly painted, they were already rusted, right out of the box – that is not uncommon. But concrete is quite like a sponge and wicks the moisture up from the ground below and releases into the basement air or whatever is in contact with the floor. If you tape a piece of plastic to most basement floors, floors that appear to be dry from looking at them, it will soon collect water droplets trapped under the plastic. I had three in my basement. They can rust out in as little as 10 years. Most pressure treated lumber is rated for 40 year minimum when buried under damp or wet soil and most will last much longer than 40 years. I have pressure treated posted buried in my fence that are over 40 years old and most are fine. I have never seen a pressure treated support post in a basement that has rotted out. I’m sure it may happen eventually, but am quite certain it will last many times longer than the average hollow steel support post.
On average how far apart should jack post be installed from each other?
Hello Tom! I’m looking to buy a home built in 1955. Near the corner of the stairs on a main support beam is a split jack. It looks to be in good condition. It is the only one in the basement and is about 3 feet from the rear basement wall ( I have pictures). Should I be worried this is a structural issue or just some extra support for bracing. The agent tried to tell me it was used for shimming when the furnace ducts were installed, which makes no sense to me. Thanks!
Sounds like what you thought most likely some extra support. To be sure you could have a qualified contractor, engineer or architect take a look and give their opinion. IF that is the case, just be sure to maintain to prevent rusting issues that could lead to failure of the support.
Could be anywhere from 6 inches to 20 or more feet, depends on the type of support needed, and many other factors. No way to answer this in a general way, every situation needs to be evaluated and some type of calculation performed. Best to consult with a local contractor, engineer or architect for the best answer.
So insightful. I never knew the different names of Adjustable “split” jack. That was the new thing i got to learn from this article
Not sure if this thread is still being checked but…
With all thing being equal (load capability), do you have a preference in support type/material?
Wood, metal, concrete filled lally, etc?
I am digging out a basement in the pacific north west – it’s wet in general. So rust is a concern.
There are 6×6 wood posts in place now, 40 year old house – I have concerns about new wood posts (more likely 6×8) shrinking over time as its a ‘new’ variable in an already settled house.
Engineer is suggesting wood (for cost) but not sure wood is built the way it used to be!
We recently bought a 1915 house with an attached barn which serves as the garage. The barn/garage has a full-height basement beneath it (odd but not unheard of here in rural NH) with a poured concrete floor and concrete block foundation. According to the home inspector, the concrete-filled lally columns and adjustable steel columns that are supporting the main beams are generally adequate from a spacing perspective. However he did recommend we replace the adjustable columns with something more permanent: either installing new ones with the screws at the bottom and encased in concrete, or wood (as you mentioned in an earlier post). I was also considering building some kind of concrete block pier. Any thoughts or suggestions on which would be preferable?
I found an Akron Adjustable Jack Post on Lowes.com. Their how-to video states “Can be used permanently as secondary support along with the approved primary support.” What is considered secondary support? I added an extra beam only 6′ away from the primary beam (fear of sagging floors with new kitchen), so I would assume mine would be considered “secondary”?
Not sure, best to contact your local code enforcement.
Since there could be a considerable load above I would highly recommend an architect or engineer or qualified foundation contractor to evaluate and recommend, the post or pier supports most likely should have a proper footer which will need to be investigated as to what is present.
Sounds like I would also lean towards wood, pressure treated timbers should do a fine job and will last for many decades especially if placed on a pier or raised footer.
Glad you got something out of it.
Hi my name is lennon, I need some advice. I know you have not seen my house but maybe you can still help. My deed says the house built in 1900. Its older then that. Its the typical style from then,big two story with attic and basement witch is also part crawl space, 2200 square feet, 10ft ceilings on main level with 6ftx9ft door ways and 9ft ceilings on second floor. We also have two chimneys one is where my furnaces(2) and hot water heater (all gas) are vented. The bottom of the chimney fell out as its a corner of the crawl space. I rebuilt three sides with rock and brick but winter came to fast so I finished by boxing itin with plywood. I’m also removing and replacing floors and plaster. When the duct work was installed who ever put it in cut the main support beam next to the chimney witch is starting to twist now witch in turn is causing my house to sink in the middle and the chimney is slowly moving down as well. Someone before me put two adjustable floor jacks in the basement but there only holding one floor Joyce each. Also the wall that separates the crawl space and basement ( all the foundation and wall is limestone) is starting to fall in. How can i stop the sinking fast and temporarily until I can get someone here to fix it properly or fix it my self?
We just had a home inspection for selling and we have one of these laying over in the corner (not being used to hold I beam up). this was removed before we bought by the previous owners and there hasn’t been any issues with foundation, etc, but the inspector said it was supposed to be permanent and wrote it up as a removal and that we needed to replace. I don’t think this is correct…. ?
Someone had previously installed some additional supports under my house, they are 16″ diameter based screw type bottle jacks, they are cast material. as they are not required they were just additional support, how can I justify them to a home inspector? and do they need to be resting on concrete since they have a large base already.
That would greatly depend on who the home inspector was. Some are reasonable and some are not. You could simply say, they are not structural but simple placed to remove a little deflection from the floor when loaded.
Sounds sketchy to me. You could simply ask the home inspector to back up his claim. What does he base that comment on. I also have an extra split jack unused in my basement. They are for temporary work that may have already been completed or for another job, just stored there. Was he a structural engineer.
That us too much to ask without seeing what is really going on. YOu need to get a good foundation contractor or structural engineer in there ASAP to help direct you in the right direction.