Repairing Concrete Basement Crack By Epoxy Injection
Clean and dry concrete basements, apart from offering an enhanced living space, provide a safe storage for homeowners’ possessions. But, the appearance of cracks on the concrete is quite a dissuading factor for making use of this extended living are of the house. Cracks in a basement lead to humidity and moisture caused by leaking [...]
Clean and dry concrete basements, apart from offering an enhanced living space, provide a safe storage for homeowners’ possessions. But, the appearance of cracks on the concrete is quite a dissuading factor for making use of this extended living are of the house. Cracks in a basement lead to humidity and moisture caused by leaking water. Cracks are indicative of structural problem of the basement. Nevertheless, it is possible to stop such leakage of water thru cracks by injecting epoxies and thus repair the wall structurally.
Here are the advantages of injecting epoxies to cracks:
• Cracks get sealed from water.
• Epoxies have better tensile strength than concrete.
• The application of epoxies repair the concrete structurally.
All Concrete Cracks
The basics first: All concrete basement walls crack.
Such cracks are caused due to shrinkage during the process of curing when water in the mix gets evaporated. As a result, the concrete gets stressed and the only way it can escape the concrete is thru such cracks. Generally such cracks develop soon after a foundation has been cast. But, in most of the cases appearance of such cracks is not a pointer to structural defects of the foundation.
Structural Cracks in Concrete Basement Walls
It is too difficult to confirm thru visual inspection that the crack in basement is as a result of structural defect. Yet, here are a few helpful hints that generally enable a fairly accurate assessment. If the width of the crack exceeds half an inch, there is all the likelihood of its being a structural crack. Horizontal cracks are a sure pointer of structural problems. Likewise, cracks that run down diagonally, especially from an inside corner are as a result of structural defects. Yet, at the same time diagonal cracks that appear near the corners of windows or those occurring at points where the foundation “steps down” and are less than half inch wide having nothing to do with the structure.
In case you are unable to assess the nature of crack, it’s better to hire the services of a professional engineer to make an accurate assessment. By using a crack stress gauge, the nature of crack can be accurately determined. Here’s how this can be summed up.
Signs of a structural crack
• More than 1/2 “ in width.
• It is horizontal.
• It runs on a severe diagonal.
How the Concrete Basement Wall Crack is repaired
The repairs of a crack in the basement are carried out from the inside of the basement.
The epoxies in liquid form are injected into the cracks. An epoxy is a two component materials and both are mixed before being injected. The mixed components get cured to form a hard and strong material that reinforces the wall. As a matter of fact characteristically the epoxy yields a higher compression and tensile strength than the concrete itself. Once the epoxy gets cured, there will be no leakage of water.
How the Epoxy Injection is performed
Step 1. Attach Surface Ports;
Using specially prepared surface paste attach the plastic injection ports directly above the cracks. Depending on the severity and length of the crack, maintain a distance of 6-12 inches between each port.
Step 2. Seal the Crack Surface –
Having attached the ports, cover the rest of the crack with the same paste. This is not for making the crack waterproof but just to store the epoxy in the crack enabling it to react and thus get hardened.
Step 3. Injecting Epoxy into the Crack –
The process of injecting epoxy is started from the lowest surface port. A mixer that matches the epoxy cartridge is inserted into the port. The epoxy in a semi liquid state flows thru the crack. It continues to flow along the length of the crack before coming out from the next port. As soon as you see it coming out of the next port, stop injecting into the current port and move to the next higher one. Simultaneously plug in the first port to prevent leakage of epoxy. Keep following the same procedure till all the ports have been filled up.
Epoxy Cure Time
As soon as the two parts are mixed, the process of curing gets started. They attain a semi-rigid state in about 20-30 minutes. After many days they begin to get hardened. Usually it takes about seven days for reaching the final curing strength.
Limitations:
• Epoxies cannot be used for concrete block walls.
• It’s not possible to use these for repairs of floor cracks.
