Cracked bricks on a house are the most common sign of foundation settlement. If a house has stair-stepped cracks in the exterior brick, it is likely that the footing has broken and is settling. But just because there are cracks, does not guarantee that the house is settling.
There are many aspects of home construction that an inspector should know to properly assess foundation settlement. There are many signs that should all be considered when diagnosing how a home has settled and how it is likely to settle in the future.
Here are the main causes of cracked bricks on the exterior of a house:
- Differential foundation settlement – one portion of the home is settling at a different rate than the rest of the home, causing it to settle unevenly.
- Swollen metal lintels – the metal supports over doors, windows, garages, or foundation vents are oxidizing, aka rusting, causing them to swell and lift the bricks above.
Once you know whether the cracks are being caused by differential settlement or swollen lintels, you can proceed with addressing the source of the problem. If a crack is caused by the foundation settling, the soil supporting the footing must be addressed. Any settlement is primarily a problem with the soil once the foundation is broken or cracked. If a crack is caused by the swelling of a metal lintel, it should simply be replaced. New lintels are typically galvanized which means the metal was treated with zinc, to prevent future oxidation and damage from moisture.
Here are the main causes of foundation settlement:
- The soil type cannot support the weight of the structure: footing, walls, floors, roof, etc.
- The footing was installed without adequate metal reinforcement
- The soil was not compacted properly during construction
- Sub-surface water, underground, has washed out the soil from under the footing
- Trees near the house were removed, allowing the roots under the footing to decompose and rot
- The soil has shrunken due to a decrease in soil moisture, in an area
- The soil has expanded to various degrees, with a concentration of moisture in an area
- Additional weight was added to the original structure
As with most repairs, the best solution depends on the circumstances. Unfortunately, in the case of foundation settlement, most of the issue lies with the inadequacy of the soils so the best solutions bypass the soil directly underneath the cracked footing.
The most common and highly recommended solution for foundation settlement is foundation push piers. Push piers involve driving heavy steel pipe into the ground, bypassing the problem soils, until they reach strong stable soils. The steel pipe sections are driven into the ground using the weight of the home and powerful hydraulics to reach ‘load bearing stratum’. This essentially puts your home on metal stilts, supporting your home on the strongest soil layers. The engineering and our best practices allow us to guarantee stabilization for life and also allow us to attempt correction for a more level home.
The second-best solution for foundation cracks or cracked bricks is called concrete foundation underpinning. Concrete underpinning should only be used where foundation push piers are not an option. There are times where a footing was not installed during original construction or maybe the equipment used to install the push piers cannot access an area. Only in these instances, should concrete underpinning be used. Concrete underpinning involves digging out under the cracked area and installing a new concrete footing underneath the settled area. This is a good but imperfect system because you’re adding more weight on top of the failed soils, so it is possible for this area to settle again in the future.