Before winter hits i always go around the house with caulking or foam to seal up any air leaks. I have vinyl siding and i`ve notice that the corner posts have a hole underneath, should this be sealed up with insulation foam???? I`ve already put some steel wool so the mice don`t go up.
Answer I'm not sure what you mean by hole underneath. Are you talking about damage or the gap the is there from normal installation. I would not seal every hole you see on the exterior. There has to be some way for the moisture to escape between your house & siding. Otherwise mold will build up & the wood will rot over the years. When I would build a new house, the buyers would always question spaces left in the bottom rows of bricks. It looks like the brick layer missed those areas with mortar. But those small opening are called "weep holes" which allow air flow to prevent moisture from building up in the exterior walls of a house.