5 ways Geology affects your Raleigh Home’s foundation future

Foundation Repair in Raleigh

Foundation problems in Raleigh North Carolina are sometimes caused by unstable soil.

  Many houses are not built firmly on bedrock or high-load compacted dirt. Instead, they are built on expansive soils that expand and contract as they absorb water and dry. Unfortunately, if the soil under one part of the house moves more quickly than the soil under another, stresses in the foundation and structure develop. These stresses lead to cracks in the foundation, cracks in internal walls, and sinking, buckling, or leaning foundations. Excessive ground or storm water entering the dirt near the house exacerbates the problem.

Here are 5 reasons for foundation failure:

Local Geology
Houses built on filled over ravine, ditches, streambeds are at risk of foundation settlement because of soil erosion underneath during floods, heavy rains, etc.  Moreover, some houses are also built on top of expansive soils that, as the name suggests, expand when water is present and contract during droughts.  This situation exerts pressure on the foundations of the house and may lead to differential settlement and cracking.  One of the techniques to determine whether the cracks were caused by local geology is to check if the other houses in the area also have the same problem.

Foundation Repair in Raleigh Stepped Foundations
Houses built over stepped foundations may also be at a higher risk of settlement.  This is common to houses built on hillsides where some of the foundation footings are higher than the foundation level of the other parts of the house.  In this case, the foundations uphill may be resting on more solid soil or rock that those foundations downhill causing differential settlement.  This is further exacerbated when excavated earth from uphill is used as fill for the foundations downhill.  In such cases, the earth moved downhill may not have been sufficiently compacted to prevent settlement.

Soil movement
In North Carolina especially, the ground is largely composed of clay soils. Much like a sponge, these clay soils shrink and swell in reaction to the amount of water in them. The foundation drops when the soil dries out; it rises when it is wet and swells. This dramatic movement can cause the basement and foundation walls to crack and buckle.

Poor Building Site Preparation
Cut and fill situations, where soil is removed from part of the lot and stacked on another, must be compacted properly before your home is constructed; otherwise unexpected movements of the soil beneath the foundation may occur.

Poor Ground Preparation
Improperly graded home sites often lead to future foundation issues. Grading should always divert water away from your home as to not allow water to seep under the foundation.

For a professional foundation repair expert to inspect your foundation, call Brackett Foundation now.

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Ben Brackett, President of Brackett