What is Loam?
Loam is a type of soil which consists of relatively even parts of sand, silt and clay. It is of moderate density and is considered to be the best soil for growing crops and gardens.
Loam as a foundation
Loam is a very stable soil on which to build a house. It drains well and shows little change due to moisture and temperature.
Problems with loam
Construction on loam can present a problem when the builder has used foreign soil to add to the substrate. If this fill has a more clay-based constitution, the soil can expand causing problems with structural movement.
Problems generally occur when a moisture gradient occurs underneath the building. Faulty guttering, periods of heavy rainfall or overwatering can cause saturation around the perimeter of a house while the middle remains dry. This differential can cause parts of the house to shift at unequal rates causing cracking and separation in materials.
Another major concern is erosion. If excessive water flows beneath your house it can create a fluid situation where the foundations ‘float’ loosely. Over time this can cause major damage and costly repairs.
How to protect your home on loam
- A well maintained gutter and down spout system is crucial in order to keep balanced moisture around your foundation.
- Grading of the surface around your home should always direct water away from the perimeter.
- Install an automatic watering system that activates for short periods at regular intervals, drenching your garden but not your foundations.
- Keep a close eye on any signs of structural movement (i.e. cracking in walls, difficulty opening and closing doors, excessive cracks in plaster) and engage the services of a housing engineer to advise you on repair work.