Does Vinyl Rot
Because the vinyl itself is unaffected you may not notice water infiltration or the issues that it causes rot mold and mildew until it s too late.
Does vinyl rot. That lifetime vinyl covering can droop and and warp pretty quickly. And when it s installed properly with a good waterproof membrane will act as a rain screen. If you leave the rot in place it will spread and could eventually affect structural members or attract wood eating pests. Vinyl siding is not nearly as low maintenance or attractive as it first appears.
Vinyl siding itself is water resistant just like any plastic product. While proper installation should guard against moisture becoming trapped beneath the vinyl siding if this does happen it will accelerate rot promote mold and mildew and invite insect infestations. They will frame around rotted window sills and brick moldings cover up rotted trim etc. Unlike wood and masonry vinyl siding presents its own breed of maintenance worries.
Wood that gets wet can eventually develop rot mildew mold and or leaks. Vinyl siding does not keep water from getting behind. My house needs to either be painted or sided and i would rather side it but a couple of old timers have told me that since i live in a very humid area that moisture will get trapped between the vinyl siding and the wood siding and cause the house to rot undetectably. If vinyl siding is functioning as designed most surface rain water will run right off it.