thermal breaks between steel beams

[SLTA]

What do y'all think of this? From the article:

'There are a number of variables that impact a material's structural performance, of course, but Haley says, "the compressive strength of our thermal material is 38,900 PSI where A36 steel is 36,000 PSI." He continued, "The connection is up to the structural engineer, but the TIM material properties were chosen so that the structural integrity of the connection will not be compromised." '

http://www.buildinggreen.com/live/index.cfm/2011/6/30/Structural-Thermal-Breaks-for-Steel-Framing

I think the key words there are "the connection is up to the structural engineer."

 

[SteelPE]

I love it when the green people are more worried about heat loss through thermal breaks than they are with regards to structural integrity/continuity.

I just had to come up with a detail to place roof insulation under a brick support at a low roof/wall location. Simple detail to create, but annoying that I needed to come up with it.

I like that they are using 36,000 psi when most steel is 50,000 psi (not that big of a deal). I would be interested to see some of the other engineering parameters like E.

 

[SlideRuleEra]

For a "thin" thermal filler using the detail shown in the link, the compressive strength of the TIM material is the most important structural property. Both shear and tension are carried by the bolts, not the TIM material. A portion of TIM material is compressed during bending, of course. Since the bolts are taking the structural loads, the statement "the connection is up to the structural engineer" is accurate... just as it would be for the same flanged joint WITHOUT the insulating sheet.

I have to agree with SteelPE that sometimes these well intended concepts can be taken too far. In the detail shown, for example, both "Thermal Insulation Bushings" and "Thermal Insulation Washers" are used to reduce conduction through the bolts. Because of the round-about thermal path through the bolts, IMHO, additional heat loss through the bolts is minor and not worth the trouble of dealing with "Bushings" and "Insulating Washers". The TIM sheet itself is good enough.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[ishvaaag]

I love even more reading the CO2 output of 4 days of the last Icelandish active volcano is bigger than the whole CO2 savings in Earth in the 60 year long age of "green" consciousness... I don't mean Earth needs not to be cared, but humbuggers would do better work trying to plug volcanoes.

 

[Djinh]

@ishvaaag:

Volcanoes don't actually emit much CO2 at all:

http://www.skepticalscience.com/volcanoes-and-global-warming.htm

 

[csd72]

Djinh,

Yes I have heard the volcano thing debunked also. So much misinformation out there on the web. More opinion and rumour than fact.

Good article.

 

[Teguci]

There has got to be a better way. Don't really like the idea of steel beams sticking through my exterior envelope. If we are talking about a balcony, I'd want to use the slab as the tension flange of the cantilever (maybe carbon reinforcement?). You'd have to thermally break the slab at the door. Ughh. Just keep the green in your pocket.

 

[connectegr]

The was briefly introduced at the recent RCSC meeting. RCSC does not allow any fill material other than steel. Little more than an introduction was given in the meetings "new business", so we are a long way from a spec approved procedure.

http://www.FerrellEngineering.com