What is settlement?
Settlement is the physical movement of a structure’s foundation in relation to the soil upon which it is built. The reality that we face is that all structures will experience some degree of settlement over time. Yes, your house is moving, albeit very slowly. This movement is not inherently a bad thing and in fact is expected. If the settlement is relatively equal and gradual across the entire structure, you will likely never even be aware it has occurred.
What is differential settlement?
Indications and symptoms of movement arise in the structure when settlement becomes uneven. This is called differential settlement. In this case, areas of the structure are moving disproportionately with one another creating tensions within the structure usually manifesting in cracks. These cracks may appear in the foundation, concrete slabs, exterior brick and on interior surfaces. Differential settlement, though not ideal, is fairly common and occurs in varying degrees. In many minor to moderate cases the usual prescription is to correct any contributing factors such as poor grading around the structure and missing downspout extensions. Follow up by sealing or repairing existing cracks and then monitor those areas for indications of further movement.
When should I be concerned?
When assessing settlement, cracks are one of many things taken into account, in particular: size, length, location, orientation, quantity, displacement and so on. As well, we consider any other symptoms such as windows and doors that stick, door frames out of square, uneven floors and water penetration. Time frame is also a relative factor. Cracking on newer foundations may be of more concern than a 50 plus year old home. Cracking that has recurred after an area was recently patched signals active movement. Always take all relevant observations into account. When indications of more severe differential settlement and foundation issues are present it is cause for concern. It’s time to call in foundation specialists for further evaluation and repair. The severity of the problem and underlying cause will determine your next course of action.
