Comment: Having worked with steel, copper, aluminum, and silver

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Having worked with steel, copper, aluminum, and silver

I can tell you that steel is by far the least heat-conductive. Also, back when I gave earth-sheltered construction seminars I was told by an engineer that in a fire heavy wooden beams, especially big laminated beams, are more stable for roof support than steel I beams due to the latter's loss of 80% of its load bearing capacity at 1000 degrees F, a temperature quickly reached when the fire's heat collects at the top of the room or building.

Here are some images of steel beams that failed in fires:
http://www.oregontruss.com/truss-info/applications/wood-vs-s...
(Scroll down to first photo.)
http://blogs.sj-r.com/behindthecurtain/index.php/2009/05/03/...
(Scroll down to sixth photo.)

New Hampshire and Ecuador.