Has anyone built a home on steel posts ?
I thought about just digging post holes about 2-3 feet deep, then concreting in 2" steel pipe after welding a flat plate (1/4"x6"x6") on top for the sills to rest on. Going up through the bottom of the plate with lag screws would secure the sills. Has anyone did anything similar ?
I'm no metalurgist, but 2" seems small for the weight a house could end up having. I like the idea though.
You could run utilities up trough the pipes...or out for plumbing.
This is from our friend Jonsey from down under. He did a steel post foundation
http://users.tpg.com.au/jonsey/progress.htm
While it probably would work fine, in a permit situation I am pretty sure the local offiicials would require engineering and quality certification. No permit- no problem if built sufficiently strong.
You could use sections of lally column... known properties and code recognized, prebuilt beam connectors available from Simpson and USP. I have no idea what a lally column costs though.
Just for the sake of discussion, my old AISC steel construction manual says a 3" standard pipe (3.5"O.D., 3.068"I.D., .216" wall thickness, weighing 7.58 lbs per foot) unbraced column 6' long will support a concentric load of 33,000 lbs. It decreases to 30,000 lbs at 8' long, and 26,000 lbs at 10' long. By way of comparison, an 8" pipe weighing 28.55 lbs. per foot would support 140,000 lbs concentric load unbraced at 6'. Tremendously strong, but designing the foundation so as to avoid lateral loading of the columns, and/or bracing to accomodate it, would be imperative.
You can download a tech file on adjustable steel pier spacing and bracing requirements here. This information is good for Australia and may be of some use to your engineer in the US. There are adjustable stumps available over there as well. As soon as I find the site I will post it, in the meantime Amanda may be able to help.
http://tinyurl.com/bxhmy
Here is a drawing of a modified version of my stumps you may like to look at it, feel free to use it if it's of any use to you. There is a caveat though. I am no engineer so you will need to have it checked by some one who knows. Frost heave is not something I am familiar with. I have not worked in areas that cold; you will get better advice on that from some of the others on the forum.
Link here.
http://users.tpg.com.au/jonsey/house/stumpdrawing.jpg.
Thanks, Jonsey! Lots of very cool stuff on that Bluescope steel website, including rainwater harvesting stuff and pre-insulated steel building wall panels.