Basement Steel I-Beam spanning 25ft

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Posted by: from Toronto
12/3/2011 at 10:19:36 AM

I would like to remove columns in my basement, and replace current beam with a steel I-beam. Ontario building code section 9 states for that span, a W12x26 would be required. What would be an equivalent in a W8 or W10? I've worked out a W10x33 would be equivalent, but looking for any experienced insight.

Can a block foundation support such weight? Or would a 3" diameter column at each end be required?

Planning on underpinning as soon as beam is installed. Any foresight would be appreciated.

Gonna need a structural engineer, just attempting to do most of the leg work to reduce costs.

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Date/Time12/3/2011 at 11:06:36 AM

Good Morning Mike;

Different areas have different regulations. By trying to establish structural minimums on your own is out of the question.

Hire the engineer who is familiar with the codes in your area. He will outline what is required and then, check with your municipality for the necessary permit requirements.

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Mike in Toronto
Date/Time12/3/2011 at 11:22:39 AM

Chuck thanks for your reply. I'm in the Scarborough area, and city permit requirements are based on whether they meet the Ontario Building code Section 4 and 9. If they don't contradict the code, they are acceptable, if they do, a structural engineer would be required to determine a solution to the problem.

That's what I was told while inquiring at the city's permit office.

I like the learning aspect of this project, therefore determining what is mathmatically plausible, and then having an engineer approve or reject it. I am a plumber in the ICI sector, so do have some knowledge of the construction sector.

Anyone can say it's impossible, this is a forum to ask questions and get answers, also known as learning. When I do hire a structural engineer, I atleast wanna know what I am talking about, and the different options that are available to me!

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Date/Time12/4/2011 at 8:23:19 PM


Chuck is right, and there is no cost savings by trying to do the engineers work for him. He still needs to perform his due diligence, is he's worth his salt.

Underpinning before the beam is installed is an option, as you may require a better and bigger foundation for supporting the new beam, which means equipment, cutting, excavating and pouring.

A good basement? Underpinning contractor will have a more informed opinion on methedologies.

Best of luck,


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Date/Time2/10/2012 at 4:54:43 PM


I am not sure if you have completed this project or are still considering it, but here are my two-cents:

We have recently completed a project of this very nature for a client both wanting to remove teleposts AND underpin and lift a portion of the exterior foundation.

In consultation with our subcontract structural engineer, we decided that sandwiching the existing beam with a C-Channel on either side, with bolts though, proved a much more cost effective and timely solution than replacing existing with an W Beam.

Because we also were underpinning the exterior wall, it was a simple matter of calculating the load now transferred to that exterior wall (from the previous teleposts) and upgrading the underpinning for that specific area (if I recall, we installed one additional pile at that area).


Geoff Muller

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