and no bedrock to speak of at all. Clay soils those found in areas where the ocean was once move dramatically with the introduction of water and the denial of water.
Last year when we did not have a drop of water during the hot summer for over 100 days, our soils split up and you could drop a 6 foot fence slat into the crack and it would disappear, this is not a joke, I did it in my front yard. Well this also is happening under the foundations, especially slabs which we are almost 75%.
What we do is to run the black soaker holse all around the home, 16 inches from the foundation. This does not spray, but weeps water.
In the summer without rain, I do this once every week all night, then do the other side of the home the next night.
If this is not done, the ground separates from the slab and you could drop a soft ball between the slab and the earth. We are also constantly back filling sand and sandy loam soil into this crack to fill it in and then water it in to melt it into the soil.
Ram Jack, Cable Lock, and many others have developed many new approaches in jacking up foundations that have dropped where the piping and electricity cords have literally snapped from stress and streching.
Many friends up north hear this and think that we are real idiots, but you have to see what we are against during droughts.
It is a fact, that with our soils, 30 days with out rain and in the baking summer, then you get a heavy down pour, your foundation could move up 2 inches over night. Fact.