Originally Posted by
Amt0571
At the moment, when it rains, a couple of walls develop some wet spots. It's not like there's water pouring from the wall, it's just that if you touch it you can feel it's wet.
Is this going to cause damage to my bikes?
Probably. Eventually.
I'd stop the source of the moisture intruding. Without that, you'll have very moist water vapor all throughout that space. And it'll settle on the components, bolts, etc. Eventually rusting. No way around that, unless stopping the intrusion. Which would take shoring-up the porous walls, of course.
Sounds like a garage re-wrap & re-slatting is in order. Spring's coming up, and with it neighborhood barbecues. Perhaps the neighbor's icy exterior will thaw a bit, sufficient to allow the problem to get dealt with properly.