Chimney Support

[Mike Lamb]

This is holding up a 2 story brick chimney. I think I am getting numb as to what is holding up these 100+ year old frame homes.

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[kurt]

That post could hold up several 2 story chimneys.

Folks think there's some form of atomic entropy wherein wood frame buildings just fly apart, collapse, or otherwise disassemble themselves.

Uh uh. They're probably among the most resilient structures ever built.

Back in the 'early-mid '80's when Lake Michigan was at record highs, there were a lot of houses over in Michigan washing into the lake. Waves would undercut the bluffs until the whole dune would slide into the lake. I'd see old farmhouses cantilevered out over the abyss...1/3, sometimes ever 1/2 the house just hanging there completely unsupported. Of course they were sagging, but still hanging there.

Then, it was into the lake. Sometimes they'd hang there for months.

[Marc]

Comprehensive strength of wood

This is a list of common wood species and their compressive strengths. All are over 2 tons per square inch. A 2X4 red oak fails at over 35,000 lbs. Incredible!

Marc

[Mike Lamb]

I listed no important structural concerns here despite the precarious look of this support.

The floor joists were a real 2 1/8" x 10". The rafters were a different story.

[Steven Hockstein]

It is very difficult to calculate the composite structural strength of all of the different parts of a building and how they work (or not work) together.

Every once in a while I will get a call from a contractor that is working on one of our projects. The conversation will lead to a discussion about why the building is still standing because they opened-up the walls to expose the structure and were surprised at what appears to be a minimal amount of support and no obvious signs of failure.

[Mike Lamb]

It is very difficult to calculate the composite structural strength of all of the different parts of a building and how they work (or not work) together.

Every once in a while I will get a call from a contractor that is working on one of our projects. The conversation will lead to a discussion about why the building is still standing because they opened-up the walls to expose the structure were surprised what appears to be a minimal amount of support and no obvious signs of failure.

I believe toe nails, paint and caulk have remarkable structural power that can't be measured.

[Jim Baird]

Steve and Mike,

Bucky Fuller used to talk a lot about what he called "synergy", the cumulative effect of all the components of this or that system. An idea that likely applies here.

[Jerry Simon]

The floor joists were a real 2 1/8" x 10". The rafters were a different story.

2x4's, 2-3' o.c. with no ridge rafter?

[Mike Lamb]

The floor joists were a real 2 1/8" x 10". The rafters were a different story.

2x4's, 2-3' o.c. with no ridge rafter?

Yes. Very typical. Several cracked rafters.