I hope you all can help me DIY's been a great resource in the past. The previous owners of my house added an addition connected to my kitchen - however, the construction was poorly completed and have left us with a host of gaps ranging from 1/2 inch to 1 inch. (instead of adding the addition to the kitchen seamlessly it was attached to the outside brick, with the brick painted over) You can see cleanly through these gaps to the outside. They occur between the walls and where the wall meets with the floor. I've crawled under the addition but cannot reach these gaps from the outside. I'm afraid concrete will shrink given the high humidity and overall dampness. The gaps are so large I'm hesitant to use caulk (silicone or otherwise) to create a proper seal. This would prove instrumental to me since we live in a wooded area and have a real problem with field mice (who have invaded my den and kitchen this winter - my cat tries to keep up as does our exterminator) and the problem won't be solved until we've plugged the gaps.

I have a home that was built in 1952 on a slab. The problem that I am running into is that the outside walls on NE, E and SE corners in the winter time get wet when there is something place too close to them. This will begin to mildew after a bit. What causes this and how do I fix this.