I have just bought a house and it has a 20 x 30 worshop outback. It's a metal building on a concrete slab. They did a pretty good job putting it together but there are many gaps between the walls and the slab. Also, there are many places in the walls and roof where they missed their mark for the screws and so there many holes. My question is how do I seal this building? I want everything sealed! I live in Georgia so this summer I would like to run some AC out there without cooling the entire county. Thanks.