Unsafe Telepost column (C) Daniel FriedmanStructural Column & Pier Defects

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Structural column defects:

This article explains how to notice defective, damaged, improperly supported, or missing structural columns, and other structural column & pier mistakes.

Here we will discuss missing structural column or post footings & piers, missing Lally columns that were removed during remodeling, use of temporary columns & jackposts, Improper bearing support at Lallys & teleposts. We include photographs of structural column mistakes. We explain how to evaluate rust damage to steel columns, posts, adjustable columns in homes,

Our page top photo shows a telepost used as a "permanent" supporting column. Most models of teleposts or "jackposts" are thin-walled steel and are not designed for permanent use. And all columns require proper bearing support at both the column top and bottom. This leaning, cockeyed jackpost is a structural collapse waiting to happen.

Detecting omissions, such as leaving out a column or it's pier or footing is an important step in learning how to recognize and diagnose various types of foundation failure or damage, such as foundation cracks, masonry foundation crack patterns, and moving, leaning, bulging, or bowing building foundation walls.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Structural Columns in Residential Buildings: Visual Inspection for Defects

Northridge Meadows Earthquake collapsed column (C) Daniel FriedmanThis 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.

Watch out: Some of these residential column or post defects are dangerous and risk collapse. But do not fail to pay careful attention to the structural connections themselves: connections between posts and beams, posts and piers, beams and the floors or ceilings they support.

Connection failure is often the weak link in residential structural movement and collapse.

See DECK COLLAPSE Case Study for an example. FYI we call a 6-inch concrete filled steel column a Lally column after its inventor.

Some folks call these just steel columns, or lolly columns or steel posts.

Article Series Contents

Proper Use Compared with Misapplication of Temporary Teleposts or Jackposts in Structures

Our photos below show a proper use of a temporary column, telepost, or jackpost - that gray screw-jack to the right of the white-painted steel column I am touching. The second photo at right shows why the temporary column was put in place: the hollow steel column supporting this beam had rusted through at its base, risking collapse.

Watch out: The collapse of a structural steel column is increased if the column is hollow, rather than concrete-filled.

Structural and temporary column uses and defects (C) Daniel Friedman Structural and temporary column uses and defects (C) Daniel Friedman

Thin-walled Steel Adjustable Teleposts - Maybe Not the Best Choice for Permanent Repairs

However what you see in the photographs above is a temporary repair. The rusted steel column should be replaced with a structural column such as a concrete filled steel Lally column that is rated for permanent use.

Thin walled telepost (C) Daniel Friedman

Our next structural column photo (above ) shows a thin-walled adjustable column in use in a wet crawl area. The repair contractor installed gravel and then plastic to keep moisture levels down in the crawl space. (The post is probably not out of plumb, that was a tilt in the camera when I shot this photo.)

But notice that the column extends down through the gravel into the presumably wet surface beneath.

Consider that the end of the column is now hidden from view in gravel, that we think this is a recurrent wet area, we can't see if it's wet or not, and more, because this is a tight crawl space, people won't enter it very often to inspect conditions there.

A more durable repair would have been a Lally column. Some builders even prefer to use a pressure treated wood 4x4 post in this sort of location, arguing that it is "rustproof".

Some Adjustable Teleposts May be Permitted for Permanent Installation

Structural and temporary column uses and defects (C) Daniel Friedman

Shown here, some adjustable screw jacks or teleposts such as some Read-I-Post columns are constructed of a heavier-gauge steel and in some jurisdictions they may be approved for permanent use in structures.

Often where an adjustable column is permitted for permanent structural use, once it has been properly adjusted in height, its adjusting rod is removed and the screw is tack-welded in place.

Structural and temporary column uses and defects (C) Daniel Friedman

Notice that the installer took care to bolt the Red-I-Post top plate to the beam underside. Let's hope that the beam itself is secured to the floor joists overhead and is protected against lateral movement.

Pipes are Not Acceptable as Structural Columns

Toy pipes support building (C) Daniel Friedman

Our photo (above left) shows a basement girder supported by cute little 2-inch pipes.

We think the installer knew these were not structural-components, because s/he installed these toy "faux-structural" pipes on 5-foot centers.

Improper Column Top or Bottom Support, Bearing, or Connections

See our page top photo for an example of a horrible installation of a jackpost that is likely to collapse. Below are more examples of improper telepost installations. At below left we have inadequate bearing surface and no connection between the steel bearing plate and the joist underside. It looks as if the post may also be out of plumb. Boing!

Structural and temporary column uses and defects (C) Daniel Friedman Structural and temporary column uses and defects (C) Daniel Friedman

Which End Goes Up When Installing Screw Jacks & Teleposts?

Our second dangerous telepost photo at above right you can see that the post top screw has bent the steel plate as it pushed into the beam, and the whole assembly is slipping off of the beam and moving to the right. 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.

Supporting Column Location

Improperly placed supporting column (C) Daniel Friedman

It seems obvious that in addition to spacing requirements for supporting steel columns below beams (typically a steel column is placed every eight feet on center in a wood frame two story residential structure), you would also place the column below any splices in the beam.

But a splice in a structural beam also needs resistance to bending upwards. Look closely (click any of our images to see a larger view) and you'll see some nice wood putty in that opening splice joint.

The splice shown in our photo of a home in Portland ME would probably not have bent if it had been located below that floor joist to the right, and had the supporting column placed below the splice as well as below the joists.

Improper (Hollow) Structural Columns Failed at 1994 Northridge Meadows Earthquake

Northridge Meadows Earthquake Collapse 1994 (C) Daniel Friedman

As we also discuss at EARTHQUAKE DAMAGED FOUNDATIONS, defective supporting columns failed at Northridge Meadows during that 1994 earthquake. It appears that hollow 6" pipes were substituted for concrete filled steel Lally columns under part of the building. Once the fireproofing wrap was installed it was not possible to spot this shortcut by visual inspection.

The hollow columns failed, permitting the upper floors of the structure to collapse. There were fatalities.

Here are examples of types of omission that contributed to a structural collapse. During our work at the Northridge Earthquake site in California in 1994 we noticed that some of the supporting Lally columns were hollow rather than concrete filled.

Northridge Meadows Earthquake collapsed column (C) Daniel Friedman Northridge Meadows earthquake collapse photo showing hollow Lally Column (C) Daniel Friedman

Perhaps due to material shortages or rush during construction, these hollow, and weaker supporting columns were wrapped with a fire-barrier just as were the "real" supporting columns used elsewhere.

Our photos show a section of Northridge Meadows which collapsed during the earthquake. In the second Northridge Meadows building collapse photograph just above you can see that this column was hollow.

Our opinion was that these were defective columns and that they were a factor in the structural collapse during the Northridge earthquake. Other areas of the same complex moved, columns even leaned, but they did not collapse where the columns were of the proper type and were properly connected to the structure.

Other factors in the collapse appeared to include how exterior sheathing had been nailed across or not across certain sections of the building supporting walls. Our list of examples of defects of omission during foundation construction continues below.

See EARTHQUAKE DAMAGED FOUNDATIONS for more about the defective supporting columns that failed at Northridge Meadows during that 1994 earthquake.

Missing or Improperly-Removed Structural Columns & Posts

This topic has moved to a separate article now found at COLUMN / POST MISSING - separate article

Watch out: in a structural brick wall-built building, if one or more main beams lose their support, sag, and collapse, there is a high risk of a total catastrophic structural collapse.

Settling or Missing Column Footings & Piers Show up As Cracks, Sags, Movement

Settling pier below supporting steel column (C) Daniel FriedmanMissing Post or Column Footings / Piers

"Missing" column footings or piers may or may not be a defect depending on design and soil conditions. In some jurisdictions, a poured concrete floor slab may be considered of sufficient thickness and strength to support the column.

Of course one cannot, without special equipment, "see" through a concrete slab to determine whether or not a pier was provided or required below a post. But in some instances there will be compelling evidence of a missing pier under the slab.

What causes pier or slab settlement around or below a post?

Failure to compact the soil under a column pier or footing or under a poured concrete slab which has been placed on backfill can result in column settlement.

Our client is pointing to a supporting column in a location where we suspect that crack pattern around the column, combined with a slight but observable depression at the column base area suggests its pier may be settling.

Settling pier below supporting steel column (C) Daniel Friedman

When we see a column whose base penetrates the concrete floor slab we know the floor was poured around the column - the column was put in place first. We can't see if a proper pier was installed to support the column base - as is usually the case.

Perhaps in the installation we show here, the builder set a 4-inch solid concrete block on (poorly-compacted) fill inside the building foundation, set his post on that, and jacked away. When the fill settles the block settles too, and the column may move downwards, cracking the concrete floor around its base in the pattern we show here.

Evaluate RustedSteel Structural Columns & Posts

Crushing steel lally column (C) Daniel Friedman

Please see COLUMN / POST RUST DAMAGE where we have moved and expanded the discussion of rust or dent damage to structural steel columns, posts, or jackposts.


Continue reading at COLUMN / POST MISSING or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.



Or see PORCH COLUMN REPAIR or REPLACEMENT for the repair of round or wood columns used on porches and in building interiors

For problems with settlement of piers below Lally columns see SETTLEMENT CRACKS in SLABS


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