I-joists as studs?

[metolius]

I saw on a home improvement show I-joist that were specificaly manufactured for use as studs. they were 2 x 8 . Is anyone familiar with this or know a manufacturer.

[grumpydasmurf]

Well I would have to say they should be specifically manufactured. Correct me if I am wrong Rich, you know more about this than I. I-Joists are manufactured for tensil strength. Studs are intended for compresive strength. Mixing the two may not be a good idea.

Since the studs were manufactured I would say they were probably engineered first too. I've never seen it.

[Rich]

Yes grumpy typically the top chord of I-joists are in compression and bottom chord is tension - and studs are pretty much in compression across the whole thing. There are some cases where studs will have uplift but it's typically negligible. I'm sure there have been I-joists manufacturered for specific purposes - but never seeen an I-joist in a vertical application. There would be no reason that I could see where it would be useful.
Was it a microlam type product - maybe plastic lumber? I've seen some plastic lumber like that.

[metolius]

no. wasnt microlam or plastic. what i saw was a ijoist with 2x3 finger jointed top and bottom cords. the webing was chip board that ran i think four feet with four inch gaps

[Rich]

I realize what you saw - but I'm just saying that I've never seen TJI's used in a vertical configuration. The only thing resembling an I-joist that I've seen used vertically is metal cavitywall framing in non-load bearing condition.
I'm not saying that there isn't something out there like that.. just that I've never seen or used it.
What home improvement show was it?

[metolius]

i wish i knew. when i saw the product i figured i'd just find it with a local supplier. NOPE. so now if i see something of interest i write it down right away

[grumpydasmurf]

Perhaps the guys using it had no idea what they were doing. Welcome to a collapse.

[metolius]

ha! that would make for good tv

[kenhuck]

I may have seen the same show. It think it was a farm redevelopment in Vermont. Increasing air tightness and adding more insulation at the time of construction can have very attractive returns on dollars invested.

This is a hot topic for me as I am committed to building homes that use a quarter of the energy used in a new energy code compliant homes.

The field is known in the US as Superinsulation, in Germay they are called passivhaus or passive house. An ideal passive house has no active central heating plants. About 4000 such home have been built in Europe.

TJI in Germany has produced brochures that discuss the finer points of this vertical application. Katrin Klingenberg an Architect built such a house using TJI joists in Urbana, Illinois her total energy bill for a winter month is $35.

best regards,
ken huck
Susten(R) Building Systems
"We build in comfort and economy(sm)"
kenhuck@jps.net
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[waltF]

Kenhuck is right.

There are construction details available for everything you want to build wall constructions with I-studs. Some 1000 homes have already been built with these details in Germany. Sorry, no chance for action-tv.

You find construction drawings from Trusjoist/Germany ("Hochgedaemmte Wand und Dachkonstruktionen im FrameWorksTM Bausystem) and from Finnforest ("Stiele in ein- und beidseitig beplankten Wandtafeln nach DIN 1052") - just to name the two biggest producers.

You find examples at www.passivehouse.com. These houses save more than 75% heating energy compared to contemporary European standard new buildings.

The Smith/Klingenberg Home at Urbana is the first passive house built in the US. It was built using I-studs in the wall construction.

[kenhuck]

:idea:
A detailed article about the Klingenberg Urbana Passivhaus is now available at
http://www.naima.org/pages/resources/library/order/RP064.HTML

It is good to see the insulation industry advancing its interests by making the article available for free.

BTW: I think that Katrin might now say that the house has a bit more insulation than was necessary. However the economic sensibility of any building insulation system is a function of energy prices over the entire life of the building. Energy prices have been steadily climbing since Katrin's walls were enclosed and the 30 to 50 year life of the house is enough time for much to change so it may yet turnout that those R-60 walls were a sound investment.

In my opinion for every 10% increase in average energy price Katrin's house increases in value by about 2%. This can be expected to increase as technological improvements enable the prices of energy from different primary sources to become more tightly coupled and energy prices increasingly move together following the ever upward prices for fossil carbon fuels.


kenhuck@vcn.bc.ca

Susten(R) Building Systems
"We create economically efficient
buildings for people who want to save money
and take concrete action to sustain the
health of the earth and its inhabitants."

mobile (828) 273-5334
land (408) 223-1303

[kenhuck]

The show in question seems to be Bob Vila's Home Again.

During the Vermont Farmhouse project / season Bob made about 5 side trips to Cobb Hill Cohousing in Hartland Vermont.

Home Again episodes beginning with 12 are about the Vermont Farm house. These shows can be purchased online at Bob Vila's website.

I have spoken with Mark Albee the general contractor on this project and he seems to think the the Canadian manufacturer of the 8" joist is out of business.

The Cobb Hill project is a good example of superinsulation however it probally does not restrict heat loss enough to be called a passive house.

The ideal of a passive house is to make insulation so efficient that you do not need a central heating system. At the very least the system can be scaled back to a point where its capital costs are reduced. I am seeing this in my solar thermal heating system designs. From what I know this is not what happened at Cobb Hill. They seem to have had a great deal of difficulty due to inflexible Vermont environmental standards.

[Cole]

Both of you, welcome to the forum!!!