Replace a lally column when it has lost steel to rust, is bent or out of plumb, sits on the floor slab with no footing, isn't fastened to the beam above, or is an adjustable column that's unlabelled or extended past its rating. The replacement itself follows a set order: find out why the old column failed, shore the beam on both sides, remove the old column, confirm or rebuild the footing, set a new column cut to the exact height, fasten it top and bottom, then let the shoring off. It's structural work, so it belongs with a qualified contractor, and with a designer or engineer if anything about the load or footing changes.
"Lally column" is the US name for a steel pipe column, often filled with concrete. In Ontario basements the same job also covers teleposts (adjustable steel columns) and fixed steel posts. For the price side, see cost to replace or remove a lally column.
Signs a lally column needs replacing
| What you see | What it can mean |
|---|---|
| Rust with pitting, flaking or holes, especially at the base | Lost wall thickness and strength |
| Column leaning or out of plumb | Footing settlement, beam movement, or a poor original install |
| Bent, kinked or dented column | Overload or impact; capacity reduced |
| Column standing on the slab, cracked concrete around it | No footing; the slab is carrying a load it wasn't built for |
| Gap or loose shims at the top | Column not fastened or not bearing evenly on the beam |
| Telepost with no label, or extended past its marked limit | Not a permitted, rated column under the Ontario code |
| Missing pin or loose screw on a telescoping column | The adjustment is not locked |
| Jack post left from an old repair | May be a temporary shoring product, not a permanent column |
| Sagging or bouncy floor above | Column, beam or footing not doing its job |
Any one of these is reason to have the column looked at. Several together, or a sagging floor, are reason to do it soon. Don't try to straighten or jack anything in the meantime.
Surface rust or a real problem?
Basement columns rust from the bottom up, because that's where water collects: a damp corner, a floor drain that backs up, a leaking foundation wall or a garage floor with meltwater and salt.
- Surface rust: an orange film, the steel is still smooth and solid underneath. Clean it, prime and paint it, and fix the water source.
- Section loss: flaking layers that come away, deep pitting, holes, or a base that is visibly thinner than the steel above. The column has lost capacity and should be assessed for replacement.
- Hidden base: a base buried in a slab patch or flooring can rust out of sight. If you can't see it, it hasn't been checked.
The Ontario code requires at least one coat of rust-inhibitive paint on exterior steel columns (Article 9.17.3.3). Basement columns aren't covered by that article, but paint is still simple protection for a column in a damp space.
When a column isn't plumb
A column that leans carries its load off-centre, which pushes sideways on its top and bottom connections. Common causes:
- The footing settled on one side, or there was never a proper footing
- The beam moved, often because the column was never fastened to it
- It was installed out of plumb to fill a gap
The fix is rarely to knock it back into line under load. The beam is shored, the cause is found (often the footing), and a new column is set plumb, fastened and centred. Article 9.17.2.2 of the 2024 OBC requires columns to be securely fastened to the beam they support, and Article 9.17.2.1 requires them to be centred on a proper footing.
What to replace it with
| Option | When it fits |
|---|---|
| Fixed steel post (pipe or HSS with welded plates, cut to height) | Most permanent replacements; no adjustment parts to loosen or tamper with |
| Labelled telepost to CAN/CGSB-7.2 | Where the load is within 36 kN (Article 9.17.3.4) and the designer agrees |
| Engineered column | Loads above the telepost limit, or columns outside the Part 9 scope |
Steel pipe columns under Part 9 need at least a 73 mm outside diameter and a 4.76 mm wall (Article 9.17.3.1), with end plates of at least 100 x 100 x 6.35 mm, and the top plate across the full width of a wood beam (Article 9.17.3.2). The telepost limit is explained in can adjustable steel columns be permanent.
How a lally column replacement is done
The order matters more than any single step:
- Assess. Find out why the old column failed. Rust from a water problem, a missing footing or a beam that moved will come back unless it is dealt with.
- Check the permit. A like-for-like swap is sometimes treated as a repair; a new footing, moved column or changed load is a structural alteration. Ask the building department.
- Shore the beam. Temporary shores go in on both sides of the column, bearing on solid ground or slab and snugged to hold the beam where it is.
- Measure. The new column's height is measured with the shoring in, at the exact location.
- Remove the old column. Once the shores are carrying the beam, the old column is unfastened and taken out. A concrete-filled pipe column is heavy, so plan how it will be cut or carried.
- Deal with the footing. If the old column stood on a proper footing in good condition, the new one can use it. If there's no footing, or it's cracked or undersized, the slab is cut and a new footing is poured to the drawings. See lally column footing requirements.
- Set the new column. Centred on the footing, plumb both ways, fastened to the beam at the top and secured at the base as detailed.
- Release the shoring. Slowly, so the beam settles evenly onto the new column, then remove it.
- Inspect and finish. If there's a permit, the work is inspected before it's boxed in. Paint the column and keep the base dry.
The full new-column process, including footings and fastening, is covered step by step in how to install a lally column in a basement.
Garage lally columns
Garage columns, often supporting a beam under a room above or near the garage door, take more abuse than basement ones:
- Salt and meltwater from vehicles pool at the base all winter. Rust at the base of garage columns is common and often worse than it looks.
- Impact from vehicles can bend or shift a column.
- Exposure. A column in an unheated garage is closer to outdoor conditions, so a good coating matters.
The replacement steps are the same. Ask your designer whether the new column's base can be kept clear of standing water, and whether a protective coating or a bollard makes sense where vehicles park.
Replace, upgrade or remove?
Some owners replacing a column decide to remove it instead to open up the space. That's a different job: the beam has to span twice as far, which usually means a new or reinforced beam, heavier supports at each end and engineering. See can you remove a lally column to open a basement before deciding.
Replacement steel posts made to your height
We fabricate fixed steel posts with base and cap plates welded on, cut to your measured height, and we supply and install basement beams and posts. Engineering services are available for projects that need them. Send us photos of the column, its base and the beam it supports, with the height for a free quote, and see our services for how we handle installation.
Frequently asked questions
When should a lally column be replaced?
When the steel has lost section to rust, the column is bent or leaning, it sits on the slab with no footing, it isn't fastened to the beam, or it's an unlabelled or over-extended adjustable column. Light surface rust on an otherwise sound column can usually be cleaned and painted instead.
Is a rusty lally column dangerous?
Surface rust is mostly cosmetic. Pitting, flaking layers, holes or a base that has thinned noticeably mean the column has lost strength and should be assessed. The worst rust is usually at the bottom, where water sits against the steel.
What do you do if a lally column is not plumb?
Don't hammer it back into line. A leaning column usually means something moved, such as the footing or the beam. Have the cause found first; the fix is normally shoring the beam and installing a new column, set plumb on an adequate footing.
Can a lally column be replaced without a permit?
It depends on the scope and your municipality. A like-for-like swap is sometimes treated as a repair, but a new footing, a moved column or a changed load is a structural alteration that normally needs a permit. Ask your building department before work starts.
