My central AC compressor unit is outdoor resting on a concrete pad. The pad is 48"x48" in size and 4" thick and it is reinforced with steel rod. I believe the pad is original so that will put it back to 1980 when the house was built.
Recently the concrete pad started to fail. First a crack started about 8 inches from one edge, then more cracks along the outside edges, chunks of concrete started to fall off exposing the rusted steel rods inside. The compressor has four legs and it's bolted to the pad with concrete screws. Of course with the pad failing two of the compressor legs will no longer be resting on anything solid real soon.
Obviously I need to remedy this situation. But I have two questions:
(1) Is it normal for a pad to fail like this after 20 years? Why did it not fail after 8 years or 12 years? If it waited 20 years, does it mean there is some other factor involved? Like perhaps the soil below is yielding due to a sink hole (house is in coastal south Florida sandy soil high water table) or sewer line leak?
(2) If I replace the pad how would I go about doing it? I cannot just lift and move the compressor aside which is very heavy and has very rigid connections into the house's attic. A new pad will take a day have the form done and the concrete poured, then a few more days at least to cure. I will have to wait a while to put the compressor on again...do I get a concrete repair place to fix this or the AC place to fix this?
Thanks,
MC