I am often asked "What is the most common problem you find?" That actually is an easy answer for me. In the Birmingham area, we get lots of rain. Where does this rain water go? The answer to that question is the most common problem I find.
The first thing I examine is the lay of the land. Quite often there is a steep slope that ends at the house. This slope may be from a hill behind the house, a neighbors yard or even the front yard of the house. If the yard is not graded correctly this water is washing up to the foundation of the house and is either coming into the basement or crawlspace or is washing under the foundation. Another problem I encounter is water washing under driveways or sidewalks which eventually leads to cracking and settlement.
Where the water off the roof flows is another issue. Quite often downspouts dump their water next to the foundation of the house. If there is nowhere for the water to flow it will soak in next to the foundation and will show up in the basement, crawlspace or under the foundation.
Is the house water tight. Are there gaps in the siding, bricks, around window or doors that will allow water in. This can lead to rotten wood, mold, and water damage in the walls and ceilings of the house.
What problems are associated with water not being channeled away from the house? I have seen shifted foundations, concrete slabs that have cracked and fallen, mold on walls, water pooled in crawlspaces, rotten wood, and even mushrooms growing in a basement. Take a look at your house and make sure that you don't have a water problem.