Rust damage to steel posts or columns:
We explain how to evaluate rust damage to steel columns, posts, adjustable columns in homes, and we illustrate the difference between harmless cosmetic or surface rust and serious exfoliating rust, splitting columns and risk of building or floor collapse.
This article series explains how to notice defective, damaged, improperly supported, or missing structural columns, and other structural column & pier mistakes.
Our page top photo shows a split, crushed steel column that resulted in the partial collapse of the floor above during an inspection by the author [DF].
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Watch out: Some of these residential column or post defects are dangerous and risk collapse.
This article describes a structural column defects in residential buildings. Larger structures using supporting columns and piers certainly require additional professional design from a civil or structural engineer or similar design professional.
As we also discussed at BASEMENT LEAKS, INSPECT FOR, even a concrete filled steel Lally column can deteriorate enough to lead to building movement or instability. But hollow steel columns such as teleposts and even steel pipes people sometimes think will support a building, heavy exfoliating rust on the columns can lead to crushing or splitting and a structural collapse.
When evaluating the history of water entry in a building we like to look at structural components that have been in place since the building was completed - those are parts that will have been exposed to flooding or recurrent wet floors if water entry has been a problem.
Light superficial rust on a Lally column base is not structurally significant, though it might indicate a history of wet floors in the area. The rust shown at the Lally column base at below left is just a chip, it is insignificant, and we concluded that there was no evidence of a history of wet floors in this basement area. The steel column at below right penetrates the floor slab - we think it may sit on a hidden pier (there was no sign of settling).
But the column surface rust at below right suggests the floor has been wet in this area. We did not think this column had suffered damage that risks it's structural integrity. Click THIS LINK [photo] to see another photo of rust on the base of a steel column in a basement that we verified over a 12 year life had been subjected to recurrent wet floors but never flooding.
More photos of superficial rust damage to a hollow residential structural steel post are at POST COLUMN RUST MINOR.
But when we see exfoliating rust, some careful poking around to see just how much damage has occurred can help us decide the urgency of replacing the column - and of course fixing the water entry problem .
WATER ENTRY in BUILDINGS will help with the latter.
In our steel post rusty-base photo above we show serious exfoliating rust at the base of a steel column. It's reasonable to infer that this home has been subject to recurrent flooding to a depth of several inches.
If the post above is a traditional concrete-filled steel Lally column, even with rust damage it's resistant to sudden catastrophic collapse.
Watch out: however if the steel post is a hollow unit, severe rust can lead to either gradual or even sudden crushing of the bottom of the post - an event that can cause a building catastrophe.
Our inspection of a second rust-damaged structural steel post (photo below) was very exciting.
We were inspecting a house on Long Island when the owner mentioned that she had pumps running 24/7 in the basement to keep Long Island Sound at bay. Some Long Island New York homes located close to the water were constructed with a basement floor that was close to or sometimes even lower than water levels in the nearby Long Island Sound or its waterways, creeks, canals. Those buildings invite constant water-entry problems and related water damage.
In this Long Island home there was a forest of steel supporting columns (some were just hollow pipes not real Lallys) in the basement - all of these steel posts were badly rusted.
As the owner, who was a big person, walked across the floor, the kitchen floor suddenly collapsed and fell down about a foot. We wondered if an earthquake had suddenly struck Long Island.
Trembling we both took another look in the basement. The Lally column shown above and supporting part of the kitchen floor had picked that moment to crush. It was rusted through from repeated flooding.
Also see FLOOD DAMAGE TO FOUNDATIONS.
2016/11/25 [Anonymous by private email to the editor]
Today, as we were cleaning out our garage, we noticed that one of the support columns for our 1965 split level home has a large rusty dent (about an inch tall) at the bottom. This support column, which we believe is original to the house, is holding up the second story bedrooms which extend over the garage.
We purchased the house about a year ago and do not know how long the dent has been present or what caused it. We have attached pictures taken from several angles.
Would you say this rusty, dented area is a problem that needs to be addressed or acceptable?
[Click to enlarge any image] Photo: a close-up of the bottom of the steel column described by the reader's question.
Thank you for the interesting support-post question. A competent onsite inspection by an expert usually finds additional clues that would permit a more accurate, complete, and authoritative answer than we can give by email alone. With that arm-waving done, I comment further:
From just your photos I infer that there has probably been a history of wet basement floor in at least the area of the post. Given that the home is 50+ years old, the total amount of rust on original post is not terrifying. I can't tell if what you're seeing includes evidence of any actual crushing of the post bottom.
If the post is crushing then it's an older type, no longer permitted, that is hollow. A modern Lally column used in this location would be filled with concrete - a detail that resists both bending and crushing.
But many older homes used steel columns that were hollow. Just how much of a risk of structural damage hollow steel columns might suffer from rust depends on:
While I'm not a structural nor civil engineer, I expect that those professionals would all agree that light, superficial rust on a steel column is only cosmetic in effect, though it might warn that steps should be taken (get rid of water, paint the steel) in a residential structure like yours to protect the column from further rust. Thick flaking exfoliating rust on the other hand, seriously compromises structural steel.
At COLUMN / POST RUST DAMAGE we show serious rust damage to a hollow steel column that crushed, resulting in the sudden collapse of a kitchen floor of a Long Island New York Home in an event that scared the hell out of the author.
I would pick up a hammer and first give rap or two on the post side at mid span. If it rings or sounds hollow, it may in fact be hollow, in which case IF there is crushing or bad rust you'll want to replace it. If the noise is more of a "thunk" the post is probably concrete-filled and crushing/bending of any significant amount is unlikely.
Below your photo shows this hollow steel column indoors in a finished garage.
Next, with a screwdriver, poke into the base of the post a bit. If you find it's soft rust and your screwdriver goes in to concrete, there's no urgent repair. If you find that the screwdriver pokes through rust into a hollow space up above the floor level then the column is hollow.
Finally: look for other signs of the extent of water entry and any related problems (moldy insulation, drywall, or rot or insect damage), and if needed, take steps to dry out the basement. A sickening amount of such guidance is at InspectApedia.com.
Thank you so much for your helpful response. We tapped on the post with a hammer today and it seems to be hollow (As are the other three posts located in our house. If in good shape, are these other hollow ones considered to be ok?).
The metal of the dent was still intact, so we were unable to verify using the screwdriver approach.
The post is located in our garage and we believe the dent/crush area may be due to a horizontal impact of some kind.
The rest of the post seems to be in decent shape with the exception of this roughly 1 inch tall by three inch wide dented area. Should our next step be to hire a structural engineer?
Also, please feel free to share the photos
With the caveat that nobody can afford enough insurance to promise a stranger that their house - completely unknown and un-seen except for a few photos sent by the correspondent - is "safe" or "structurally sound", still, looking at just your photos I can see no reason whatsoever to hire an expert for structural assessment.
If you saw signs of building movement, settlement, cracking, leaning, bending, bowing, heaving, then that would be a cause for further concern. A dent in the bottom of one hollow steel column with light, non-exfoliating rust on the column base, is not justification for requiring a structural engineering analysis of the building.
Take a look around your home for signs of movement or for superficial, recent cosmetic repairs that might cover such movement, or for floors, walls, ceilings that if not cracked or bent, bulging, leaning bowing, are nevertheless visibly out of plumb, square or level.
I do not mean to sound glib, but in sum, there's not much justification for worry for just this one column if there is no settlement and no significant damage. Superficial or surface rust is not likely to itself represent damage to the structure.
The risk to you of being hurt falling down the stairs when going to the basement to look at this column is greater than the risk of the dented lightly-rusted column by itself. I mean, watch out for a "capture error" in which something you see so captures your attention that you fail to attend other higher-risk situations. Make sure your home has working smoke detectors/alarms, sound steps and railings, and that there are no obvious hazards in the electrical or heating systems.
If you had a home inspection prior to purchase of the home, you might ask the inspector if she/he saw signs of concern for damage to the structure as well as asking what repairs are needed to address Dan's 3 "D"s:
See FEAR-O-METER for an explanation of the importance of focusing your energy on things that are Dangerous, Don't work, or that are causing rapid, expensive Damage to the home.
see OTHER PEOPLE's MONEY for an explanation of why some consultants give you advice that is expensive for you, free for them, and that mostly is focused on reducing risk for the consultant rather than for you.
We appreciate your reassuring email and are certainly happier to think this is not a major problem.
In your previous email, does the word "crushing" refer to a vertical crush, like from a downward force? We had thought it included the horizontal impact (crush?) that may have caused the rusty notch at the bottom of our post. For the most part, our house seems as straight as an arrow.
We don't see any evidence of other settlement beyond a very slight dip in the threshold of the master bedroom and some uneven wall tile in the bathroom (we think it's just really old, poor tile). Everything else seems very strong and straight. The inspector did not have any structural concerns.
He did not see this area of the post in question due to lots of clutter, but from what he could see of the house, he raised no structural concerns.
One more question, if that's ok - in order to protect the column from further rust damage around the base, should we pick off the rust flakes and then paint over it? - 2016/11/28
Horizontal "crushing" of a steel post or column: good point. I agree that a post or column might be damaged by horizontal impact, and I add that a dent might be caused by both impact (even a hammer) OR in a case of heavy loading or overloading of a too-thin, under-sized column denting could be an early stage in "crushing".
But those manifestations of column overloading in a residential property would be very very rare.
More likely somebody smashed a column near its top or base as a heavy-handed step in aligning the column to a plumb position.
If the column is hollow (a telepost, adjustable column, pipe, etc) denting is far more likely than if the column is filled with concrete (a Lally column).
When I refer to "crushing" I mean that a badly-rusted steel column actually crushed downwards from weight from above - shown in my photo just above, and discussed in more detail
starting at COLUMN / POST RUST DAMAGE
To protect the steel column in your home from further damage:
Our car porch was built 23 years ago and consists of a metallic frame supported by four hollow metal columns (each with a 4.2-inch diameter) and is covered with a ceramic-tiled roof, vide attached photos.
Lately we discovered to our horror that the 4 metal pillars are corroding with one covered with heavy thick rust flakes. Before we engage a building engineer to have a look, there are several disturbing questions running through our minds at the moment such as:
1. Will any repair/s ensure that it will last at least another 10 years?
2. It cost us US$10000 to build it in 1994. Repairing it might cost at least half that sum and rebuilding another similar structure might cost at least thrice the original price.
3. In the interest of safety, would it be better to demolish it altogether. After all, we don't really need a roof over our car.
My wife and I would appreciate your expert advice and views on how we should proceed. - Anonymous by private email 2017/12/05
You are right to be concerned about the columns in your photos, particularly because you report that they are hollow steel. A hollow steel column, if badly rusted, can crush at its rusty bottom, leading to a structural failure.
From your photo above it looks as if someone tried a previous repair by wrapping the column bottom in concrete.
I cannot of course fully understand the situation from just photos, but from what I can see I would think there is absolutely no need to demolish or abandon this car-porch (or carport) just to repair the columns.
When you replace the columns you might consider using concrete filled steel posts if they are available, or otherwise taking care to coat the post bottoms and to do what you can to protect them from corrosion.
There are two approaches that a contractor would take for replacing the columns in your car porch:
1. If the loss of space were no issue he might leave the existing columns in place, and would add new columns next-to the existing ones in a position that lets the top of the column be connected to the overhead beam.
2. if the loss of space by having double side-by-side columns is a problem or if that repair is just too ugly, the contractor would install temporary support columns a few feet away from the existing ones, to give working space.
Then he would remove and replace the existing columns one-by-one.
Photo: detail suggesting the points at which the top of these steel car porch columns were probably welded to the roof structure and where angled supports were included.
I've also consulted my two close friends who are engineers and they concurred with your advice that there is no necessity to demlish the structure.
They suggested I should get a good conractor who is familiar with such repairs to do the job.
I managed to get one who will start work tomorrow.
He recommended scraping off the rust from the bottom of each column and repaint the bases with antirust.
This will be followed by drilling a small hole to pump in a strong cement composite into column base and seal the holes before wrapping each column base with a strong cement footing.
Continue reading at PIPES USED as POSTS? or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.
For problems with settlement of piers below Lally columns see SETTLEMENT CRACKS in SLABS
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