Key takeaways
- Clay swells when wet and shrinks when dry, and the movement pulls and pushes foundations.
- Water management is the cheapest way to keep clay stable.
- Soil tests show how deep the supports should go.
Why clay moves
Clay soils are made of tiny plate-shaped particles that hold water. When clay soaks up water it swells, and when it dries it shrinks and cracks. Foundations on top of it see this as seasonal lift and drop.
Different parts of a house can move differently, especially where trees, gutters or sun change how wet the soil is.
Tennessee's ground
The Nashville Basin has clay over limestone, the Highland Rim has rolling red clay, the Plateau has thin rocky soils, East Tennessee has clay and limestone in valleys and slopes, and West Tennessee has deep loess silt and clay. Each has its own issues.
A soil test or site evaluation shows what is under a specific lot.
What helps
Keep soil moisture steady. Direct gutters and downspouts well away from the house, slope the soil away from the walls, avoid planting big thirsty trees near the foundation and fix leaks quickly.
When movement has already happened, piers carry the load down past the zone of movement.
Related services
Quick answers
Should I water my foundation in a drought?
Some homeowners use a slow soaker hose to keep soil moisture steady in dry spells. It should be gentle and consistent, and over-watering can cause problems of its own.
Do trees damage foundations?
Large trees close to the house can dry the clay and cause settling on that side, and roots can lift slabs and pipes.
Ready to talk it through? Get a free estimate or call 615-209-7643.