Video: Cantilever Using Steel

hardy siding, hardie board, masonry, steel, architect

Hi again. Nathan here. I ran across this series of pictures form a few years ago in my files, and I thought I’d share them with you for today’s video. It’s under the topic of steel in remodeling.

Now, this section of the house you see with the hardy-board siding is an addition. The existing structure is brick here. And, of course, you’re noticing there’s something strange about this addition.

This is a 72 degree angel on this corner, and you can see it in the roof line and in the rest of the house. It had to be done this way to some kind of property line restriction. And so it was done this way, and the roof was allowed to run normally.

This created a situation where steel had to be used in this long cantilever on the far hip. Now, you definitely want an architect involved in a situation like this but to just give you a brief sketch of why steel would be needed…

A wood beam can generally only cantilever about an amount equal to the depth of the beam or maybe a little bit more in some cases.

So what does that mean? If you had a 2×12, then nominally that beam would be about 11 and 1/4 in depth, then you could get away with a cantilever of about 11 and 1/4.

It varies place to place in what the codes will allow. If you double them up, you might be able to get 15″, something like that.

So, obviously for a cantilever like this – a cantilever’s where we have no support on one end – its got to be steel.

And just by way of helping you from a planning perspective, as you think about a project that might involve a cantilever like this, realize that you’re also going to have to do some serious thinking about what will be inside this wall to support the steel.

Remember steel is incredibly heavy. And, of course, here we have a cantilever which means that all of the (assuming the piece of steel is about double all that we see here)…well, that means this support is exactly halfway. This support, whatever’s inside this wall, is supporting the entire beam and everything loaded onto it. That’s a massive amount of weight and wood is not good enough. It’s going to need to be metal or masonry. Probably steel or concrete is inside this wall to provide the support that would be needed.

So that’s just to help you think about a project where this might be the answer for you.