1st- I live in South Carolina and all of my duct work is under the house, nothing in the attic. I have just replaced all of it with new. The new duct work is sweating alot, not near the vents in the corners, just in the middle of the house and where there are no vents. I have 8 vents total around the house and about 1000 sq. ft of crawl space. I've posted before about putting fans under the house to get air flowing under the house and JAY J replied telling me not to do this cause it would make my problem worse. Is there anyone that can give a second opinion of this. (Sorry Jay).
I put a new vapor barrier down over the old one and gave it about a week, then crawled back under the house. There were small puddles of water on the barrier. Mostly from the duct work sweating but also from some of the copper water pipes seem to have weak spots in them. There are a couple of places that have a small circle about the size of a dime that water is building up at. You wipe the water away and it seems to leak thru the circle. Someone told me the pipes may have weakened thru time (20 years) from the telephone company grounding the wires to my pipes???? I talked to a plumber and he says no way that this is the case.