Foundations are essential to every building structure. They serve to distribute the vertical load of building materials, occupants, and belongings to the soil. Foundations also keep the soil around and under the building from pushing it out of position. Therefore, when you discover an issue with the foundation, there is a need for considerable concern.
Foundation Types and Materials
Several types of foundations can have unique problems. Knowing your foundation type and materials is helpful to make the most educated assessment when evaluating foundation problems.
Basement
A basement is often defined as an area mostly below ground and has a ceiling height of at least 7 feet. The basement floor is usually a nonstructural slab of concrete, although a basement may have soil as the floor.
Common basement foundation wall materials use poured concrete and concrete blocks in newer houses. Common basement foundation wall materials in older homes are bricks and stones.
Crawl Space
A crawl space is an area below the living areas with a ceiling height of less than 7 feet. The crawl space floor is usually soil. Crawl space foundation wall materials are concrete blocks and bricks.
Concrete Slab-on-Grade
A slab-on-grade foundation is built by removing the topsoil, leveling the soil, and pouring concrete on top.
The concrete may be a thick slab of uniform depth (a mat slab). The entire mat slab is effectively a footing. Mat slabs are used only in warm climates where the frost line is near the surface.
In cold climates, footings are dug around the perimeter of the building to below the frost line. Then, a thin, nonstructural slab of concrete is poured over the rest of the foundation (a monolithic slab).
Concrete Slab-on-Stem Wall
A slab-on-stem wall foundation is built by digging footings around the perimeter of the building to below the frost line. Walls are built on the footings to a point where the foundation is level and high enough to allow water to drain away from the foundation. The area inside the walls is backfilled, and a thin slab of concrete is poured on top.
The concrete may be thicker at load-bearing points inside the walls, but aside from these points, the rest of the slab is not considered a structural load-bearing element. Note that garage floors in basement foundations are often concrete slabs-on-stem walls.
What Are Foundation Cracks?
Foundation cracks are one of the most common foundation problems. Bad soil, or soil that is too wet around the foundation, can cause the foundation to crack and lead to other foundation problems such as:
- Settlement: Downward movement of the foundation
- Uplift: Upward movement of the foundation
- Rotation: Movement of foundation walls either inward or outward
- Bulging: Part of the foundation wall protrudes outward from the rest of the wall.
Cracks that occur with other foundation problems may indicate a structural problem. A qualified professional, such as a structural engineer, should evaluate these cracks to determine the causes and appropriate repairs.
Call Jackson and Sands Engineering today! We can help you know if you’ve got cause for concern, and what can be done to rectify the situation.