Can anyone tell me what to be careful of if you have aluminum wiring in your house. I was told that if the wall gets hot, I need to tighten the screws of the inside switch. Is this true and if I didn't, would it actually cause a fire in the wall. If this is true, how often does it loosen?
Aluminum Rated Receptacles
Several answers are very good but the one thing that evrybody failed to mention is each device (switch, recept, fixture, etc.) must be listed to use with AL wire. This is the biggest problem I find. Home owners run out to the local hardware and pick up a new device and do not check the listings. The copper wire pig tail is an option but once again you must use a wire nut that is listed for both AL CU wiring. Most are a dark purple in color. Electrical Inspector
Aluminum wiring contracts and expands more than copper wiring of similar size. This means that it has a tendancy to loosen the screws on the outlets over time. As the screws loosen, the resistance in the circuit goes up - this resistance manifests itself as heat. If it gets too hot, it can start fires. My parents owned a house with aluminum wiring, that they sold to me. In the 35 years total we've owned it, I think we've tightened the screws on the outlets three times total. Only once in all that time have we had a wall get hot. The most recent tightening was during a major repainting where we actually replaced the outlets and switches with decorator ones as we painted each room.
There are several ways to take care of your problem. 1) Change all the wiring to copper. 2) Pigtail with copper wire and al/cu wirenuts to all new devices 3) Use copalum at all your boxes (this method is the best, besides replacing all your wiring to copper). Basically it cold welds the aluminum to the copper and makes a molecular bond. It's pretty expensive, and you'll have to look to find someone that actually knows how to do it, and has access to the crimping tool. Going around and tightening your devices won't hurt, but won't be fixing any longer term issues you may have with the aluminum wire. Keep in mind that if the original installation was done correctly, your circuits aren't overly tapped, and all the wires are on the appropriately sized breakers, then you may not have to worry much. Just run dedicated lines to any your new circuits. In other words, don't tap off these circuits. Hope this helps.
For an immediate fix ,all switches and outlets should be checked to make sure the screws are tight. With aluminum small gauge wire #12 and #10 the screws will continue to loosen up over time because of the nature of aluminum( expanding and contracting). Repairs in the past have been pig tailing copper tails with approved wire nuts or using special switches and receptacles. It is my understanding that the Copalum crimp method is the best solution for aluminum wiring on switches and outlets. Check out information about this method on the net and seriously consider hiring and electrician that knows how to do this crimp method. Some electricians use the purple wirenut to pigtail copper but there have been problems with this method not working. Loose connections with aluminum wire is a serious fire hazard. Good luck.
