My family and I are looking at buying a rental property and I had a few concerns regarding the basement. First, the basement has standing water on the floor and the walls are crumbling. Do you think the standing water is related to the crumbling walls? If not, what do you think it's from? What do you think the cost to fix would be?
I do some construction work but personally have not dealt with many basements while we build in California. Just a couple of thoughts and questions though.
If the walls are concrete and crumbling, and they are exposed on the outside to dirt, then yes if there is crumbling in the wall, it's likely that water will find its way in.
How is the ground outside? Is it sloping/grading towards the house?
Are all four walls crumbling or just one wall specifically? I would check to see if there are bad gutter connections outside on that part of the house, and for sure check the slope. There might be some telling signs by doing a thorough look about the exterior of the property.
Also, I would be a bit hesitant to buy a house with standing water in the basement. If you are really sold on the house though, then it's always fixable. Just depends on how much it costs to fix it. They might have to lift the whole house up and rebuild the foundation, or it might be a couple of repairs. It could go either way.