rust underneath

[ScottMan]

I have a 1 yr old Skyline that I found had been rusting underneath from nearly the start. The house is 2300 sq ft and is on a slab. I have noticed condensation when running the A/C but otherwise it is as dry as the outside air. I believe that I don't have the 1 sq ft / 150 ft floor space venting. I have only 10 vents (about 1 sq ft each) but I need probably twice that many. I posted on the other forum and want to follow up with how to repair it. I have some questions:

1) Do I really need to paint a rust inhibitor over ALL the frame and metal down there? Will it otherwise rust out and the home will fall?

2) Where can I get larger (4 sq ft) vents? I got the standard hardware 1 sq ft vents but cannot find anything bigger. I know if I replace with these I will be ok. I have OSB w/ Everrock skirting.

[Tom]

If you correct the situation now, I dont see any reason to paint quite yet. This is a judgement call basically. I dont know where to get any larger vents, other than fabricate them yourself. Just adding more vents should solve the problem. Tom