Foundation cracks
Did you know that certain types of cracks are quite common and won’t cause any issues, while others can be a symptom of significant structural damage? Below are descriptions of potential causes of cracks in your foundation:
- Shrinkage Cracks: As your concrete foundation dries, shrinkage may occur, and small cracks might appear as that happens. Typically, these cracks will begin near the floor and will not reach to the top of the foundation. Shrinkage cracks are one example of cracks that are not structural.
- Settling Cracks: Another example of cracks that are not structural are those that can develop as the home settles. This type of crack is usually wider at the top and may or may not reach to the bottom of the foundation.
- Cold Pour: Can you see horizontal seams on your foundation that angle upward? These can occur during construction as the concrete is being poured. When one load of concrete begins to harden before the next load is poured, these cold pour seams can be the result. While not structural in nature, they can still lead to leakage.
- Structural Cracks: Buckling or bowing walls, as well as cracks that run either vertically or horizontally, are common signs of a structural crack. This term refers to any crack that can jeopardize the structural integrity of a home. 95 % of structural cracks are found on block built foundations. Most cracks on solid cement foundations are not structural
Leaking Solid foundation wall crack repairs.
Most times 2 options are available for repairing leaking cracks on solid foundation walls.
- Interior repairs– Basement Waterproofing Solutions developed a system for repairing foundation cracks on solid cement foundation walls in the early 1970s and we have been utilizing this exact repair system since. We offer a transferable 20 year warranty on all interior crack repairs.
The foundation wall is mechanically scraped clean to the bare foundation surface. If the crack was previously repaired, all previously applied materials need to be removed from the wall. (Including paint) Next, we chip or cut a groove into the wall along the crack. The wall is than cleaned and filled with a hydraulic cement mixture. After the cement dries a heavy grade epoxy and rubber coating is applied over the hydraulic cement. Upon drying all material bond together as one.
What makes this repair so successful? The hydraulic cement stops active leaking cracks and the epoxy and rubber allows the crack to continue to expand and contract as it seals the crack. The water will eventually push its way back into the ground. A common question is asked-Will the water that enters the crack eventually erode the foundation wall from the outside? The answer is no. We have had the opportunity to examine these repairs over the last 50 years have never once any type of erosion.
- Exterior repairs– Exterior wall repairs are warrantied for lifetime are transferable to new owners. Our exterior repair system was also developed many years ago and has proven to be successful time and time again. These repairs are performed differently than an interior repair as the water pressure is working in our favor-pushing the repair on the wall. But this does not make the repair easy. The key to a successful exterior repair is to prevent the ground water from penetrating the edges of the repair. Unlike an interior repair, on the exterior, there is no need to chip a groove into the foundation wall. 1st a hole needs to be excavate slightly lower than the foundations footing. This excavation can be as little as 1Ft deep or over 8Ft deep depending how buried the foundation is. The hole must also be large enough for a man to have enough room to address the most crucial part of the crack, which is the bottom. The foundation wall is then cleaned and dried. A primer is than applied to the wall and 2 layers of a sheet rubber membrane is laid over the primer. The membrane overlaps the footing and the second layer of membrane is cut wider than the first. Ground water will need to penetrate both edges of the membrane layers for the repair to malfunction. 1 layer of membrane will permanently repair a foundation crack, but we apply 2 for extra protection.
Block Foundation Wall Crack Repairs
Some cracks in block-built foundations do not seep water.
Some cracks in block foundations can be structural and will require a structural repair.
Carbon Fiber, steel wall supports, support buttresses and foundation underpinning are some of the structural repairs that are required on block-built walls. If a structural crack is ignored, a foundation wall can eventually push into the point of no return and a new foundation wall will need to be built. Please visit our structural /Foundation repair page for additional info.
Leaking Block Foundation Wall Crack Repairs
Leaking cracks on a block foundation wall must be repaired from the interior and exterior. Installing a French drain might be a better option in some situations. Water can enter the cavities of a block foundation from many different places and leak into the basement through a wall crack (EX: Pipe penetrations, mortar joints, wall fractures or through the pours of the block)
A leaking crack on a block foundation can be repaired same as on a solid foundation wall. Interior-Crack is cut, filled with hydraulic cement, epoxy, and rubber.
Exterior- Excavate and apply the double layer sheet membrane.
None Leaking/ Non-Structural Block Foundation Wall Crack Repairs
These cracks are not much to worry about but should be monitored. Often, they will show up on home inspection reports. Typically, the repair process can vary according to engineer or homes inspectors requirements. A common method is to cut along the crack with a diamond saw blade. Clean and fill the crack with hydraulic cement and then cover the with a silicone rubber coating. On smaller fractures, silicone calk with a finished finger bead is all it takes. This type of repair has limited ability to prevent water penetration into a basement therefore are not warrantied against water.
Foundation Cracks & Repairs
Understanding Foundation Cracks
Not all foundation cracks are created equal. Some are harmless, while others indicate serious structural issues. Here’s a breakdown:
Shrinkage Cracks:
- Appear as concrete dries and shrinks.
- Usually begin near the floor and do not reach the top of the foundation.
- Non-structural.
Settling Cracks:
- Occur as a home settles over time.
- Often wider at the top and may or may not reach the bottom.
- Non-structural.
Cold Pour Cracks:
- Horizontal seams that angle upward, formed when concrete sets between consecutive pours.
- Not structural, but can allow water intrusion.
Structural Cracks:
- Buckling, bowing, stair cracks, or cracks running vertically or horizontally.
Can compromise the structural integrity of the home.
- Most common in Brick, Field Stone and block-built foundations; rare in solid cement foundations.
Leaking Solid Foundation Wall Cracks
Interior Repairs
Our interior repair system, developed in the early 1970s, comes with a transferable 10-year warranty.
Process:
- Mechanically scrape wall to bare concrete, removing old paint or previous repair materials.
- Cut a groove along the crack and fill with hydraulic cement.
- Apply a heavy-grade epoxy and rubber coating over the cement.
- Materials bond together, stopping active leaks while allowing the crack to expand and contract naturally.
Key Benefit: Water pressure is relieved without eroding the foundation. Inspections over 50 years show no foundation erosion from these repairs.
Exterior Repairs
Exterior repairs are warrantied for life and transferable.
Process:
- Excavate a trench to slightly below the foundation footing (1–8+ feet deep depending on burial).
- Clean and dry the wall.
- Apply a primer and two layers of sheet rubber membrane, overlapping the footing for maximum protection.
- Groundwater pressure pushes against the repair, helping it hold.
Key Benefit: Double membrane ensures long-term water protection. One layer works, but two layers offer extra security.
Block Foundation Wall Cracks
Structural vs Non-Structural:
- Some cracks are harmless and require only monitoring.
- Structural cracks require carbon fiber, steel wall supports, support buttresses, or foundation underpinning. Ignoring these can lead to wall failure, requiring complete replacement.
Leaking Block Cracks
- Must often be repaired both interior and exterior.
- Water can enter through block cavities, pipe penetrations, mortar joints, or wall fractures.
- Interior repair: Cut, fill with hydraulic cement, epoxy, and rubber.
- Exterior repair: Excavate and apply double-layer sheet membrane.
- In some cases, installing a French drain is recommended to manage water flow.
***Water leaking into a block, brick, or stone foundation can cause serious structural damage if left unrepaired. When moisture becomes trapped inside the foundation, it begins to weaken the lime in the concrete, leading to cracking and deterioration. Over time, this can progress into significant structural foundation problems. Prompt and proper repair is essential to protect the integrity of your home.
Non-Leaking / Non-Structural Cracks:
- Typically monitored; repairs vary depending on engineer or inspector recommendations.
- Common method: Cut with a diamond blade, fill with hydraulic cement, and coat with silicone rubber.
- Small fractures may only need a silicone caulk bead.
- These repairs do not guarantee water prevention and are not warrantied against water leaks.
This section ensures homeowners understand the types of foundation cracks, their risks, and the appropriate repair methods for both solid cement and block foundations.