This guide will tell you how to repair cracks and fractures in a concrete wall.
Steps
Step 1. Know the problems caused by water infiltration in reinforced concrete foundations
Infiltrations can be caused by:
- Tie rods not well sealed.
- Detachments between two castings performed at different times.
- Infiltration from the water pipes and the electrical system.
Step 2. The cracks in the foundation
On some rare occasions, water can seep through a wall that has not been vibrated properly during casting, creating air bubbles in the concrete
Step 3. Repair the cracks in the wall
The only way to satisfactorily repair a crack in the foundation is by injecting a urethane or epoxy resin from the inside.
- The injection fills the crack from top to bottom and from inside to outside, blocking infiltrations.
- The old method of widening the crack and then closing it with hydraulic cement does not work in this case.
- Foundations tend to shift, and hydraulic concrete lacks the strength to withstand future movement. It would break, reopening the crack.
- Epoxy injections are considered a structural repair and will hold the foundation together if applied correctly. Urethane resins, on the other hand, will stop infiltration but are not considered a structural remedy. However they are flexible, and can withstand any movement of the foundation. It is best to use epoxy on new cracks, in homes that are 1 or 2 years old at the most. The result will be better if the crack is well defined.
- In older homes, with cracks that have already been repaired, it is best to use urethane resins to stop infiltration.
Step 4. Repair the detachments
When pouring concrete over a previous pour, a chemical bond is not created. For this reason, the joints between two castings often let water pass. The new casting must be allowed to settle for a couple of years, then the joint must be sealed with an injection of urethane resin.
Step 5. Repair the tie rods
Metal bars and tie rods are used to hold the wooden molds in place during casting. After removing the forms, the tie rods are usually covered with hydraulic cement or polymer clay, and then the foundations are covered with a water-repellent membrane. In these points infiltrations can occur if they are not sealed properly originally.
The problem can be solved by injecting a urethane resin from the inside
Step 6. Seal the ducts and pipes
During the construction of a house, holes are dug in the foundations to pass the water pipes, the drains, the electrical system. For example, water drains are usually 10 cm wide. The hole in the foundation for the pipe can be 12 cm or more, leaving a gap that is usually filled with hydraulic concrete before finishing the foundation. If this is not applied correctly, infiltrations can occur.
To repair this type of infiltration, a urethane resin is used that expands up to 20 times beyond its volume, filling the void from the inside out
Step 7. Fill the air bubbles
If the casting is not vibrated correctly, voids and air bubbles may remain in which water can infiltrate. This problem can also be solved with an injection of urethane resin.
