Dear MStone - Xypex Concentrate is used in many markets successfully for waterproofing of CMU (concrete block). This said concrete block is highly variable from region to region in terms of its porosity. Xypex has developed a system using Xypex Concentrate and Xypex Megamix I for waterproofing of concrete block that is very successful and in fact is typically done on the negative side so that the exterior wall does not need to be exposed. This might be worth trying as excavating the entire outside of your home will be very intrusive as well as expensive. Please send me your e-mail address at email@example.com
and I will forward you the technical bulletin. Alternately you can contact your local Xypex representative and they can assist you.