Steel Panel Foundations

[DenverKev]

Any opinions on this system?

Do you agree that it's the first "green" foundation for a basement?

http://www.steelpanelfoundations.com/

 

[msquared48]

Interesting product.

I would wonder though:

1. How much soil pressure can the system resist?, and

2. If the three boards installed on the outside offer any ICBO rated shear resistance, or must it come from plywood on the inside?

Mike McCann
McCann Engineering

 

[civilperson]

Still has concrete/rebar footing beneath the steel panel wall. No more green than concrete or wood. MGO is unique for panel faces.

 

[DenverKev]

Well, the amount of concrete certainly is a lot less. Some folks think that concrete has so much embodied energy that it's not very green. When it's time to recycle the materials, a small amount of steel is better than a large amount of concrete.

The chemicals in a wood PWF foundation prevent it from being burned safely in the future. Also, I really believe there is consumer resistance out there to PWF. Steel would never support mold, whereas I've seen mold eventually grow on wet treated wood.

 

[hokie66]

Why do they call this a "foundation"? It is a basement wall system.

 

[DenverKev]

In residential home construction, concrete basement walls are also called the foundation. Below that, on a gravel bed, or "undisturbed soil" is a poured footing that is usually wider than the wall.

 

[dgillette]

"Green" is strictly a relative term here. Portland cement and steel both require a lot of energy to produce, although I don't know exactly how they compare. Consideration of recycling in the overall equation seems pretty much theoretical. You don't know how long the foundation will be there, how or if it will be recycled, whether the building would come down sooner with one wall system than with the other. Well-built concrete walls have a history of lasting a long time. [This does not hold for certain basement walls that were done on the cheap, mine for example, which is further aggravated by swelling clay.] Steel certainly has more recycle value - concrete becomes gravel, and steel becomes...new steel. A couple years ago, I saw laborers with hammers and chisels chipping concrete off old rebar for recycling at a town about to be flooded out by Three Gorges Dam. I don't know if it was make-work or if the value of the steel covered their wages (no doubt very low).

DenverKev - If you want green(er) go for the tire-and-rammed-earth wall popularized in part by Dennis Weaver and his mansion in Ridgway or somewhere over there. (Google earthship + tire.) I say this only half in jest. Friends of mine got the Boulder County bldg inspectors to accept it for their earth-sheltered house in Nederland. (I'm assuming from your handle that you live in Denver CO. Otherwise, you might not know the reputation of Boulder County inspectors. I'm told they give to everything.)

 

[concretemasonry]

Not at all green -

Steel studs are killers on insulation. They can reduce an R19 insulation (theorhetical "pink-not green" lab test) to an effective R11 wall. The heavier gage studs could have even worse actual thermal performance.

Cement does require energy, but is generally relatively local. Aggregates are also local and do not represent a large amount of energy. Deliverly and distant transportation associated with iron ores, processing and delivery of finished steel products are very big factors when looking at the big picture.

A different approach - As backward as they may be in some areas, China has abandoned both wood and brick as "green" materials in favor of of concrete masonry because of land preservation, continued use of arible soil, pollution, energy to produce, transportation and constructability of an energy efficient residential structure. This started abo 10 years ago, and the old inefficient polluting brick plants are being phased out to preserve the land and soil. - Not a small job since China uses 525,000,000,000 brick each year(500 per person) and they now import wood when necessary to preserve good soil. I don't think ethanol has a good future in a country with over 1,000,000,000 people.

Everyone has their own idea of the factors in what is "green". The concept of building out of waste materials is good on a small scale until people realize the waste has value if there is a demand. - I remember when fly ash was a waste product and people paid to have it hauled away and dumped.

Dick

 

[DenverKev]

Dick,

When steel studs are insulated in this manner (on the outside), there's no thermal performance penalty.

It pretty easy to assume that a majority of new homes will be replaced within 60-200 years given the way homes typically become obsolete.

A concrete foundation can easily last that long, but what a costly pain to haul away. Steel panels will easily pay for their own trip to the scrap yard. If the hot clay soils just happen to damage the foundation, the concrete version is impossible to R & R cost effectively. Steel studs would be relatively easy to sister up and rejuvenate.

If neither style of foundation degrades, either one could be re-used under the new building. That would be the greenest outcome.