Concrete Block Foundations

Concrete block foundations benefit greatly from a waterproofing membrane.

Concrete Block Foundations

Concrete block foundations benefit greatly from a waterproofing membrane.

Concrete Block Foundations are a Popular Choice

Concrete block foundations are held together with a mortar application. They are laid in an overlapping pattern, with steel re-bar connecting them to the footings for structural support and stability. This makes them affordable and fairly simple to install.

Since they support your entire home, it is essential to keep an eye on any cracks or movement in your foundation and keep it protected from water damage. Cracks and water entry can lead to costly repairs or unsafe conditions for your home. Stay Dry waterproofing will protect your foundation from hydrostatic water pressure by draining the water down to a weeping tile or drainage system.

Key Areas of Concern

While concrete block foundations are strong and durable, and they will last longer than brick foundations, it is important to keep in mind some key areas where they can be damaged and require repair.


If the mortar is not applied properly, or if it has been damaged by movement or water, then water leakage can occur into your home. Shifting of the blocks can also be seen if they are not properly connected with mortar or secured with re-bar.

Since mortar is a vulnerable point in concrete block foundations, any signs of damage or cracking in mortar should be carefully examined. Cracks in your mortar can indicate a larger problem with the foundation’s stability, and they can lead to water entry. For these reasons, have a professional team examine any sizeable cracks for their cause.


Soil is also an important issue for block foundations as the right type of firm soil is needed to support the footings. If the soil is not properly compacted, it can lead to shifting over time, with blocks coming loose, bending or bulging.

Step Cracking in Concrete Block Foundations

Concrete block foundations work in an overlapping pattern, and their integrity is based on the pattern of overlapping blocks, and as a result, you must address any damage as soon as possible. Cracks or weakened mortar can compromise the integrity of the whole block foundation.

If you notice damage to the mortar holding your concrete blocks together, or if you notice shifting or bulging in your concrete blocks, contact our waterproofing and foundation repair team to assess the cause of the damage, the options for repair and the timeline for completing the work.

Step Cracks are Named Because of the Pattern That Appears

Step cracks appear in a stair-like pattern, due to the fact that concrete block foundations are laid in an overlapping pattern. Step cracks will follow this pattern, through the mortar, and can extend at great length as they follow the weakness in the mortar.

Step cracks are often the result of pressure from the surrounding soil onto the foundation wall. They can mean that the footings are moving, due to water or freezing that expands and causes the foundation wall to lift itself. With a thaw, the wall with then contract and further movement will occur, year after year with the change in seasons.

Repairing step cracks requires more than just an epoxy fill or cement fill. These will only be a short-term or cosmetic solutions. The underlying cause of the instability that led to the step crack requires a solution before the foundation problem can be resolved.