Foundation Settlement

A buildings structural integrity depends on what it is built on – the footing/foundation. When it is damaged (cracked, bowed, leaning, or settled), it can cause simple cosmetic problems (like cracked sheetrock), or more serious structural hazards (like differentially settled floors and walls). The reasons for foundation settlement can be poor construction compaction methods, expansive soils and/or saturated soils, poor drainage, root intrusion, earthquakes (obviously rare in this part of the state), and even karst topography (which are water soluble rocks like limestone, which is not so rare in parts of western Jersey) which create large voids. The most common culprit is clayey (expansive) soils, which generally settle over long periods of time.

The scenario a homeowner is faced with when foundation settlement is suspected, is 1) has it stopped and are repairs necessary? and 2) if it hasn’t stopped, should you merely monitor it or go ahead with what are usually very expensive repairs.

It is difficult to estimate how much any further settlement will occur without elaborate testing and instrumentation.
In many instances, the settlement merely creates cosmetic concerns, and monitoring is the recommended action. When settlement creates a structural hazard, or is noticeably progressing, it must be addressed. The foundation loads must be transferred to more stable soil (typically deeper), or to reinforce the soil. Solutions for the latter involve underpinning, buttresses, grade beams, or soil replacement. The most common remedies for the former are helical piles (augured screws on the outside of the foundation), or micro piles (in the case of low head height within the building itself). Foundation walls can also be stabilized with epoxy crack injections, soil anchors, and super-strong carbon fiber strips. If you suspect a foundation problem, BLSH&E can:

• Inspect the problem area. Take measurements, examine the loading, and confirm the structural members are adequate for the purposes they were designed for. This may necessitate subsurface inspection with a backhoe to ensure proper footing size, frost penetration depth, and of course the soil material itself. Geotechnical borings, though usually not performed, may become necessary.

• Ascertain the cause of the problem (i.e. is it poor drainage, leading to saturated soil and an over-stressed foundation?). Provide a “distress analysis report” which documents the existing conditions, provides an opinion on the cause of the damage, and makes recommendations for the best course of action/treatment. Again, keep in mind that in many situations the recommendation is to merely monitor the situation. This is especially true for vertical cracks, which tend to be less worrisome.

• Design any recommended repairs, including the aforementioned helical piles. BLSH&E does not perform the actual construction, but are partnered with specialty contractors that do this work every day. We can provide a construction estimate as well for your budgeting purposes, and examine any contractor’s proposal. Coordination and inspection during construction is also available.