A cracked basement wall shows symptoms such as leaking water, which puts the safety of your house at risk. The repair of a cracked basement wall from the outside must start with the elimination of the cause that resulted in it. Those conditions include soil pressure, water pooling, or a basement sinking.
You need to fix it for the continued integrity of your basement foundation. In this blog, you’ll be taken through the stages involved in fixing a cracked basement wall from the outside.
Overview of Exterior Basement Wall Cracks
Basement wall cracks are typically patches that appear on the walls of a basement, primarily caused by stress on the structure, moisture, or soil movement. Failure to address such defects in construction can be the basis for loss of safety in the house and would mean indefinite water ingress, the development of molds, and possibly, the sinking of the ground.
Types of Basement Wall Cracks
1. Vertical Cracks
These are the most common types, usually emerging as vertical straight lines, starting from the top to the bottom of the wall. Also, these are the result of slight settling or shrinkage of the foundation during its curing period.
2. Horizontal Cracks
The most harmful ones and an indication that the wall is bearing too much pressure. It leads to its breaking or cracking under the impact of hydrostatic pressure given by water or soil swelling.
3. Diagonal Cracks
This is partly caused by differential foundation settlement. Typically, they are easily recognizable as an off-center straight line and suggest that the building’s foundation might be in trouble. Early identification of the crack type can help owners maintain the structural integrity of their house.
Causes of Basement Wall Cracks
It is very important to determine the cause, as you will need to repair it properly. Below are some common causes for basement wall cracks,
- Hydrostatic Pressure
When water pools up around the foundation, there will be an increase in pressure against the walls of the basement. It occurs when drain paths are compromised due to poor drainage patterns or clogged gutters, which can hold enough water to produce wall cracks due to outward wall pressure.
- Foundation Settling
Over a long period of time, the weight of the home can settle the foundation. As the soil underneath it either shifts or compresses. This settlement presents stress to the home that can potentially turn a crack into a structural crack.
- Soil Expansion and Contraction
Expansive clay soils have the tendency to swell when wet and shrink when dry, thus have the potential to strengthen the void between wet and dry. The consequence creates considerable pressure on the basement walls during both wet and dry seasons, which produces cracks.
- Poor Construction
These methods start with either poorly mixed concrete or improperly cured concrete during the construction phase. This can produce a weak structure that will crack when subjected to stress.
- Freeze-Thaw Cycles
This causes issues primarily in cold climates where water can get trapped in your basement wall, freeze in winter, and expand into ice. When the ice thaws, it shrinks back, but the cracks remain.
- Tree Roots
A basement wall may be pressured by roots that grow in the soil surrounding the basement. Understanding these causes can help you protect the foundation of your house.
Step-by-Step Guide to Exterior Basement Wall Crack Repair
To repair exterior basement wall cracks and to maintain the stability of your home/building, follow this step-by-step outline,
Step 1: Know what type of crack it is
- Vertical cracking is when the crack is small; it can usually be repaired with a sealant or vinyl concrete patching compound.
- Horizontal cracks require some form of structural reinforcement.
- If you have a diagonal crack, you may consider that there is a larger issue that creates a loss of structural integrity.
Step 2: Prepare the Area
- Clean and remove any dirt, debris, or loose material around the crack. You may use a utility knife to cut away any foreign materials exposed in the process.
- In some cases, you may need to dig below the new grade. This will show the extent of your crack damage and apply a suitable repair medium.
Step 3: Clean and Dry the Crack
- Use wire brushes, pressure washers, or scrapers to remove dirt, loose materials, and old sealant.
- The crack must be dry before any repair materials are applied.
Step 4: Seal Small Cracks
- Fill the small crack with an injection-type of concrete patch (or epoxy injection). A concrete patch is typically applied to the smaller cracks.
- After patching or injecting epoxy, smooth out the surface by using a putty knife. Verify that the filled area is at the same level as the surrounding wall.
Step 5: Larger/Course Cracks
- For horizontal cracks, reinforcing a crack may involve installing straps or anchors to help hold the wall in place. It may involve drilling the wall to insert anchor bolts or using tiebacks or steel cables to pull the wall into place.
- In some cases, injecting polyurethane foam into wider cracks can seal the crack and create a barrier against water entering the crack.
Step 6: Waterproofing Membrane
- After the crack has been sealed, a waterproof membrane will need to be applied to the entire face of the exterior wall. Cracks may occur due to poor drainage or water pressure.
- When basement waterproofing, bituminous coatings are often used. They create another barrier against water getting into the wall going forward.
Step 7: Install Drainage System
- If water caused the crack to form, a crucial consideration is to install a French Drain around the perimeter of the basement, allowing some water to be directed away from the foundation.
- Ensure that the land around the foundation slopes away from the wall.
Step 8: Backfilling and Restoring
- After the repairs have healed and the wall has been repaired, it is time to backfill the soil around the crack.
- Make certain that the material you are backfilling with is clean material and properly compacted before returning it to the excavation.
- Be certain that water is going to flow away from the foundation in the future. Restore landscaping if it is disturbed by the excavation process.
Step 9: Final Inspection
- You need to check and see how well the material has adhered, and if there are new signs of water infiltration or additional cracking.
Step 10: Preventive Measures
- Ensure gutters, downspouts, and the grading around your home are in good condition to prevent excess water buildup.
By following this detailed guide, you can effectively repair exterior basement wall cracks and prevent future issues. If the cracks are extensive or if you’re unsure about performing the repairs yourself, consider seeking professional help.
Preventive Measures to Avoid Future Cracks
To prevent future cracks in your basement walls, it is essential to be proactive in addressing the causes of cracking and to manage your foundation constructively.
- Start by managing drainage around your home. Regularly maintain your gutters and downspouts to ensure water is directed away from your foundation.
- It is recommended that the soil around your basement be graded in a way that slopes away from the walls of your basement.
- Install a good waterproofing system to reduce hydrostatic pressure acting upon the walls (such as a French drain or sump pump) to avoid moisture from building up behind the walls. You need to pay attention, for example, by regularly checking for cracks or shifts.
- If there are expansive soils present and your home is built upon them, you might want to invest in some form of foundation stabilization. Foundation stabilization can take various forms, such as soil compaction and or stabilization, which will minimize the shifting of the ground below the foundation.
- Lastly, be sure to keep sizable trees away from the foundation, as tree roots can become destructive and exert pressure on the walls.
Conclusion
The outcome of preventing future cracks in basement walls is being sure to have good drainage, maintenance, and repairs. The remediation work to prevent future cracks, however, Addressing the root causes of the challenges mentioned above can help prevent superficial cracks and, in turn, reduce the risk of severe structural damage to basement walls. For expert assistance to safeguard your foundation or to Fix a Collapsed Basement Wall, professional help is highly recommended, Brick & Bolt is here to help, we offer customized solutions for waterproofing, crack repair, and structural stability.
Apoorva H P Achar