Concrete Floor Settlement Cracks

Floors dropping and separating from the walls forming a gap between the floor and wall.

Concrete floor settlement cracks. In some instances it may be necessary to excavate the area and prepare it for a course of sand to prevent settlement and future cracking. We use the three carson dunlop associates sketches shown here to comment on the occurrence causes and significance of cracks and movement in poured concrete slab construction. It is not uncommon to see 1 16th inch of shrinkage for every 10 feet of concrete length. Concrete floors with cracks or larger should be leveled.

My own home has hairline cracks in the foundation as well as numerous cracks in the basement floor. Each has its own cause and strategies to prevent or minimize. Even with the best floor designs and proper construction it is unrealistic to expect crack free and curl free floors. Before we describe crack movement and damage patterns and diagnosis in concrete slabs we need to introduce three different types of poured concrete floor slabs.

Failure to tie the concrete floor into the foundation wall with steel reinforcement during the initial pour can exacerbate this cracking issue resulting in wide or wider cracks where the. Settlement cracks in a conventional concrete floor slab which has been poured inside a separate foundation wall and often resting at its edges on the building s foundation wall footings are usually not connected to the foundation wall and are not supporting any structure except possibly lally columns discussed below. Cracks in the concrete floor. The cracks are normal concrete shrinkage cracks.

There are three main types of cracks in concrete. If the crack is larger or growing larger an active crack or one side of the crack is higher than the other then you may need to have the work reviewed by a structural engineer. If it is noticeable the symptoms will consist of small cracks that don t seem to get any larger over time. The resulting uneven surface can create a tripping hazard.

Your concrete slab floor is showing signs of sinking sagging or settling. If you see jagged cracks running at 45 degree angles throughout your home this is a telltale sign that your foundation is shifting. This shrinkage tends to pull or tear the concrete apart. However if any of the following signs are present then they could indicate a larger issue.

The settlement crack may also appear as a random crack over areas where the soil of the subgrade was not level or where it settled unevenly after the concrete was poured. Your floor may be cracking or the walls may be separating from the floor below or ceiling above. Concrete shrinks as it dries and cures.