Foundation failure is caused my multiple reasons which the major reasons are listed below. Foundation failure is where the foundation settles below level of original construction to a point where damage has occurred. Such as veneer cracking, interior sheetrock cracking, separations in the veneer and misaligning doors to name a few common symptoms.
Poor soil preparation
On some building sites, fill dirt need to brought in to level the site for construction of the footing. If the fill is not compacted properly or contains material that is susceptible to extreme volume changes settlement can occur. The builder from time to time will overly excavate corners in the attempt to put a concrete pier in. Unless the pier extends to a rock layer, the excess concrete can make the foundation heavier at this load point causing heavier settlement.
Too much rain, inadequate drainage or plumbing leaks can all cause foundation problems. Wet soil expands, pushing against your home’s foundation and over time can cause a variety of problems like bowed walls or foundation cracks. This over-saturation at the footing level can cause heaving. Negative drainage which is water that drains back towards the house can cause heave. Lack of guttering or a downspout that is not extended away from the footing can cause over-saturation and then heave. Once the over-saturation occurs the soil becomes destabilized. Once the next dry period occurs the clay will recede or shrink and the house will come down. After several cycles of this foundation settlement will occur.
Extended periods of drought or a hot, dry summer will evaporate the moisture from the ground surrounding your home. When this occurs the water table recedes causing the expansive soil to shrink. When the moisture shrinks and tightens a void will occur below the foundation allowing the structure to settle into this void vacated by the shrinking soils.
The root ball of a tree is about as wide as the canopy. If a large tree is next to your home and the branches extend over the roof there’s a good chance that the roots are growing under your foundation. The root system will remove the moisture under your foundation which can create settlement problems. This is not always the rule but if you have soil that is susceptive to shrinking it can accelerate the process.
If a plumbing leak occurs under the slab the excessive moisture can compact the fill material under the slab. When this happens a void is created and the slab will settle into the void. Slabs can settle harder due to their construction. Most homes from the early 90’s and later only had wire mesh in the concrete. A lot of our repairs that we are involved in the home had no wire mesh or rebar in the concrete. Usually the leak has been happening for an extended period of time unaware to the homeowner on the drain side. Pressure leaks are easy to detect, loss of water pressure ,increased water bill, or even can be heard. Drain leaks are the main culprit because a shower pan can leaks for years undetected as well as cast iron rusting out or a union in the pvc coming apart.