If waterproofing the walls use only the best quality waterproofing sealers that are recommended by an expert.Most common brands are not effective & are a waste of money.The ones that i've used & recommended can not be painted on they are too thick & have to be troweled on & they really work.One time I actually sealed a stone rubble foundation!if I could seal that kind of wall,sealing block would almost guarantee a good sealed wall.