The idea is that the water runs down behind it and collects in a sump in the floor and is pumped out.
The studwork then goes against this, with the rigid board insulation between, then the v.b., and then the drywall. This system collects and then discharges penetrating ground water, and also prevents interstitial condensation in the insulation and studwork.
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17,000 dryer fires a year, when did you last clean the inside of the dryer near motor or the exhaust ducting?