Shrinkage Cracks In Concrete Walls

These cracks occur when masonry panels are restrained from moving.

Shrinkage cracks in concrete walls.

When that water eventually leaves the slab it leaves behind large voids between the solid particles. The bottom line is a low water to cement ratio is the number one issue effecting concrete quality and excess water reduces this ratio. If you notice a diagonal crack in addition to wall bowing you likely have split supports in your walls. This shrinkage causes forces in the concrete which literally pull the slab apart.

Shrinkage cracks concrete once poured starts hardening and shrinking a little causing shrinkage cracks. As the name implies these cracks are very small about 0 003 inches 0 08mm in width and can be very shallow. Hairline cracks are commonly observed in freshly placed concrete and their occurrence is owed to the phenomenon of plastic shrinkage. If a diagonal crack appears near a door or window you can blame it on concrete shrinkage as with vertical cracks.

Cracks are the end result of these forces. These are very common and unless they leak or show signifi cant lateral displacement are of no structural concern. They expand when they absorb the moisture and shrink when they dry. This is the main cause of concrete shrinkage cracks on drying.

Hairline cracks in concrete. These empty spaces make the concrete weaker and more prone to cracking. Cracks of this type are called reentrant cracks. Vertical and horizontal cracks in drywall or plaster walls typically indicate drying and shrinkage which is normal after construction.

Shrinkage cracks such as shown in our photograph above are found in poured concrete are easily recognizable and can be distinguished from other types of cracks that occur later in the life of a foundation wall or floor slab as we explain here. Jagged cracks stair step cracks and 45 degree angle cracks generally signify structural movement or settling issues that are occasionally serious but usually harmless. Shrinkage cracks in concrete occur due to change in moisture of concrete. Diagonal diagonal cracks can form for the same reasons vertical cracks do.

Shrinkage restraint cracking resulting from shrinkage can occur in concrete masonry walls because of drying shrinkage temperature fluctuations and carbonation. Concrete and mortar are porous in their structure in the form of inter molecular space. They typically emanate from a corner of a window beam pocket or other opening. Shrinkage and temperature cracks are most often vertical to diagonal.