Hello, I have a retaining wall under my house that is solid concrete in PVC permanent formwork. Like Dincel or CSR Rediwall for example. It sits on a concrete slab and therefore forms a joint at the bottom of the wall where it meets the concrete slab. The problem is that when it rains, water seeps through under wall at this joint in several locations. This is causing water to get under my house where it runs across the concrete slab and then on to the clay dirt, which takes forever to dry. I need to have no rain for a month in order for it to dry. So I need to stop this water somehow. It is impossible to gain access to the back of the wall, so my only option is to apply some kind of seal to the joint at the front of the wall. I'm just not sure what to use.
I thought I could apply a thick undiluted coat of Gripset Betta Bitumen Membrane along the joint, but then I thought it might be better to use some kind of silicone in the joint first perhaps then paint the bitumen over the top? I wondered if something like this Crommelin Silicone would be suitable. It sounds like it would adhere to the concrete and the PVC in the joint. But then I read online that a hybrid MS polymer sealant is better as it bonds better to things like plastic and gives a stronger watertight seal than just silicone alone. Is that what Crommelin Hybrid MS Polyurethane Sealant is?
Can anyone provide any advice on this? Is my plan a good idea or should I be doing something else? Would any of the above products be suitable or should I use something else? Thank you.
