Ed – I’m going to suggest a few possibilities. There may be a problem with the main sewer drain that usually runs directly beneath the footing and flows toward the street. The line may be leaking and softening the soil beneath the region in question. You may have a water main leak that could be as small as a pinhole and create the problem. You may just have groundwater softening due to negative grade. Look around the yard for signs of sinking spots. Look for settling sidewalks or porch, or any other indications of softening soil. You should contact foundation experts in your area and give them all of the information. They should be able to help you with some options and permant repair ideas.
Sometimes, a disaster is not to blame for foundation problems. Rain water that is not properly channeled away from the house can causes problems to the foundation over time too. And, while foundation repair methods steps is something that no one wants to think about, everyone knows that a home’s foundation is the very core of it’s existence. It is the very first element that is made when the home is being constructed. So, it is important the foundation is level, square and free of cracks. This is essential as the rest of the house will be effected if there is a problem with the foundation. So, if you are noticing some cracking or have been affected by a natural disaster, like flooding then it is quite likely that your home is at risk.
Water is the main culprit in a major portion of foundation problems. If the foundation is of poured concrete, concrete block or stone, the continuous flow of water creates cracks which can often be disastrous if ignored.
Also regarding trees, their roots can creep into house foundations, wall footings, etc..be careful where you plant. Also, ask yourself if they are likely to fall down in high winds and do damage…if they fall will they collide with the house/garage?
Clearing the site involves removing all trace of vegetation from the surrounding area of your build and storing the topsoil in an appropriate area where it isn’t in the way and can be re-leveled to create you lawn at the end of construction.
Heating and air conditioning appliances that have a failing compressor or don’t work properly will be expensive to replace and depending upon the size of the units that will cost you several thousands of dollars.