The house I grew up in is wired with Al conductors. They are a pain in the #$% AAlmost all conections have been pigtailed with cu. A friend of my Dad's was a Union electrician back in the 70's, before there was a ul approved method. He simply used anti-oxident and either a 3m or b-cap. That was 30 years ago. I have now been in the trade myself 20 years, and done many additions and rework for my Mom and there has been no problems with his installation. This is all for what it's worth as no inspector would approve this installation today. The problem is not so much the expanding and contraction, as it is the screws backing out and then causing a poor connection causing carbon causing resistance and heat untill you have enough heat for fire. The expanding and contraction will literialy cause the screws to loosen.
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