Thursday, February 8th, 2018 by Jericca Lee
What is concrete settlement? It's simple, concrete settlement is the movement a concrete slab experiences when the soil below can no longer support the weight of it. As time passes the soil used to support concrete changes, causing your driveway, patio, garage, floor, etc., to to sink or crack.
There are different reasons why the soil may change underneath your concrete, but here are the 3 most common reasons:
The most common types of soil are sand and clay. With sandy soil, moisture really doesn't have an effect. When sand gets wet it doesn't expand in size. When sand is dry, it doesn't shrink. However, sand washes out. Clay on the other hand is the complete opposite. Wet clay holds onto the water and expands in size. When it's dry, it shrinks. When the clay shrinks under your concrete slab, that's when damage can start to occur.
Soil drys out for many different reasons, whether it be weather related, nature, or a leaking HVAC system under your floor slab. The soil beneath your concrete slab shrinks in size, it creates an empty space for the concrete to settle into causing cracks and unlevel concrete.
When water washes underneath your concrete slab, it washes away the soil supporting the weight of the concrete. This can be caused by many different reasons, some being a large rain storm, erosion, or a plumbing leak.
Sandy soil isn't normally affected by moisture changes. Although, if there is a path for water to flow beneath the concrete, sandy soil as well as other soil types, can flow along with the water passing through. This, over time, will cause sinking and caving in.
When a home, driveway, patio, or sidewalk is being built, the soil used is moved around quite a bit. After being spread out, the concrete slab is poured right on top of these fill soils. If the fill was poorly compacted, the soil compresses and settles and a void is created under the concrete. With nothing supporting the concrete it will crack, break and settle in to the void.
Take action as soon as you see early signs of settlement. The longer you wait, the worse the problem. The worse the problem, the more money. So save some money and address the problem as soon as you start to notice something. Team Vesta is always here to help with any foundation need!