We live in a brick veneer house built in the 1950s. It was built without a sill plate to cap the top of the concrete block foundation where the block meets the brick and the wooden end plate and floor joists. Cold air comes into the basement through the concrete block that is not covered by the brick, the end plate or the floor joists. Not only that, but moisture builds up on the exterior brick outside opposite the end plate. This happens during the heating season. Everything dries up during the summer. The moisture build-up is getting worse since we installed a new heating system and part of the basement is now unheated.
I've tried capping the concrete block with rigid foam to prevent cold air from coming into the basement, but that caused a moisture build-up around the end plate and a termite problem. I've tried just putting batt insulation against the end plate between the floor joists, but moisture just builds up behind the insulation and could cause the wooden end plate to begin to rot. I run a dehumidifier in the basement to keep the humidity low. That does not seem to help either.
I am at my wits end at how to solve this problem. Any suggestions? Do I need to hire a brick expert or a house inspector?