Repairing Concrete Foundation: Tackling Severe Tree Root Damage!
Table of Contents
- Introduction
- Problem with the Concrete Slabs
- Lack of Reinforcement in the Concrete
- Presence of Tree Roots
- Cold Joint Formation
- Plumbing Issues
- The Solution: Concrete Removal
- The New Concrete Pour
- Finish and Conclusion
Article
🔎 Introduction
In this article, we will discuss a case where two rooms in a house had concrete slabs that were causing issues. We will explore the problems with the concrete, the lack of reinforcement, the presence of tree roots, and the solution that was implemented to rectify the situation. So let's dive in and uncover the details!
🏠 Problem with the Concrete Slabs
The concrete slabs in these two rooms were significantly raised up in the middle, about two and a half inches. This unevenness in the floor was not the only problem; there were also visible cracks, with one crack being three quarters of an inch wide. It was evident that there was no reinforcement in these slabs, meaning no steel reinforcement was present. This lack of reinforcement could explain the significant damage and instability of the concrete.
🚧 Lack of Reinforcement in the Concrete
Upon further investigation, it was discovered that the assumption of no steel reinforcement was incorrect. As the jackhammering began, it became apparent that there was, in fact, some wire mesh reinforcement in the slabs. However, due to its rusted and deteriorated state, it provided little to no support. Working with such corroded wire mesh made the process of removing the concrete even more challenging. The use of a thinner gauge wire mesh or a ten gauge wire mesh would have been more effective in preventing bending and maintaining its structural integrity.
🌲 Presence of Tree Roots
Surprisingly, the problem extended beyond the concrete itself. As the removal process continued, numerous tree roots were encountered. The nearest tree to the house was approximately 20 feet away, but the roots had managed to spread underneath the entire slab of the two rooms being worked on. It was discovered that the concrete foundation was poured separately from the 4-inch slab on top, creating a cold joint. This cold joint provided an entry point for the roots, allowing them to grow and cause the raised floor and cracks.
❄️ Cold Joint Formation
The formation of a cold joint occurs when there is a time delay between pouring the foundation and the subsequent layer, in this case, the slab. It is common for builders to seal the joint between the foundation and the slab to prevent such issues. However, in this scenario, it seems that this precaution was not taken, resulting in a weak joint and susceptibility to tree roots. The joint allowed the roots to penetrate and raise the floor, leading to the extensive cracks observed.
🚰 Plumbing Issues
Another surprising revelation was the discovery of copper water lines buried under the slab. These copper pipes were not adequately protected with a sleeve and had been in place for over four decades. Fortunately, during the removal process, these pipes were not damaged. It became clear that the roots had made their way through the cracks in the slab and had wrapped around the pipes. The roots were primarily from a ficus tree located in the backyard, which was identified as the main culprit for the raised floor and related issues.
✅ The Solution: Concrete Removal
To address the problems caused by the raised concrete, the decision to remove the existing slabs was made. Careful consideration had to be given to avoid damaging the load-bearing walls and causing structural damage. The concrete was broken up as close to the walls as possible, with the footing serving as support. This process exposed the tree roots and allowed for their removal. The visqueen, which acted as a moisture barrier, was cut back, and the intact copper pipes were carefully protected during the removal process.
🏗️ The New Concrete Pour
With the old concrete removed and the issues addressed, it was time to begin the new concrete pour. To ensure a strong and level surface, 3/8 inch rebar was installed along with 4 inches of concrete mixed with fibermesh for added strength. Additionally, an accelerator known as 1% polar set was added to expedite the curing process. This accelerator was chosen to avoid any potential corrosive effects on the rebar. The rebar was appropriately dobie'd, and the previous wire mesh was repositioned for optimal reinforcement.
🔨 Finish and Conclusion
After the concrete was poured, it was smoothed and floated, ensuring a level surface for future flooring installation. The remaining slope was amended with thin-set or a floor underlayment to achieve a perfectly level finish. Although no joints were added, the rebar reinforcement provided the strength needed to prevent significant cracking or movement. The homeowners gladly assisted with the demolition process, and the final result provided a solid, stable foundation for their future flooring.
In conclusion, the removal and replacement of the raised concrete slabs resolved the issues caused by the lack of reinforcement and the intrusion of tree roots. Understanding the importance of proper construction techniques and preventive measures can save homeowners from the headache caused by damaged concrete. By taking the necessary steps to address these problems, a level and durable foundation can be achieved, ensuring the long-lasting stability of the house.
🌟Highlights🌟
- Raised concrete slabs causing floor unevenness and cracking.
- Lack of reinforcement in the concrete exacerbating the problem.
- Tree roots infiltrating the slab through a weak cold joint.
- Discovery of copper water lines and a ficus tree as the culprit.
- Concrete removal to address the issues and protect load-bearing walls.
- New concrete pour with rebar reinforcement and proper curing measures.
- Smoothing and floating the concrete for a level and stable surface.
- Homeowners' involvement in the demolition process.
- Importance of proper construction techniques and preventive measures.
- Achieving a solid foundation for future flooring installation.
FAQs
Q: Can the existing concrete slabs be repaired instead of being removed?
A: In this case, removal was necessary due to the extent of the damage and the lack of reinforcement. Repairing the concrete would not have provided a long-term solution.
Q: What caused the tree roots to grow underneath the concrete slabs?
A: The presence of a cold joint, where the foundation and the slab met, allowed the roots to infiltrate and thrive beneath the concrete.
Q: Were any plumbing lines damaged during the concrete removal process?
A: Fortunately, the copper water lines were not damaged during the removal process. However, they were relocated to ensure their protection during the new concrete pour.
Q: How was the new concrete pour reinforced to prevent future issues?
A: The new concrete pour featured the installation of 3/8 inch rebar for added strength. The repositioned wire mesh and proper curing measures also contributed to a durable foundation.
Q: Is it necessary to add joints in the new concrete?
A: In this case, no joints were added as the rebar reinforcement provided sufficient strength and stability. However, depending on the specific requirements and conditions, joints may be necessary in certain concrete projects.
Q: How long did the entire process, including concrete removal and the new pour, take to complete?
A: The duration of the process can vary, depending on various factors such as the size of the area, complexity of the issues, and the availability of resources.
