The Pros and Cons of Pouring New Cement Over Old Cements: A Comprehensive Guide
When faced with a damaged or old cement surface, many people wonder if pouring new cement over the existing one is a viable solution. The answer may not be as straightforward as you might think. In many cases, using concrete is recommended over simply adding more cement, as it can provide a stronger and more durable base. Let's explore the pros and cons involved in this common practice.
Understanding Cement and Concrete
Cement is a key ingredient in concrete, but it is not the same as concrete. Cement is a powdered binding agent, while concrete is a mixture of cement, aggregate (usually sand and gravel), and water. When these materials are combined, they form a much stronger and more durable substance than a simple mixture of powdered cement.
In many instances, pouring new cement over old cement can lead to a poorly bonded surface with inferior performance. Old concrete can have deteriorated due to weathering, water damage, or chemical exposure, which a simple layer of new cement might not effectively address. Instead, using concrete, which is a stronger form of cement mixture, can lead to a much more stable and lasting solution.
Light-Duty Applications: Self-Serve Car Wash Floors
Despite the complexity of some construction jobs, there are simpler tasks that benefit from the right approach. One such example is the self-serve car wash floor renovation in winter conditions. In areas with freezing winters, heated floors become essential to prevent water from freezing and causing damage.
The process for installing a heated floor involves the use of self-supporting wire mesh with a 6-inch square pattern, which is essential for holding the warm air near the floor. The plastic piping is placed at 12-inch intervals, and the heat travels through the spaces between the wires. A 3-inch layer of new concrete is then poured over the existing surface to provide a suitable base for the heating system. Since the primary need is warmth rather than structural integrity, the new concrete layer is sufficient to create a functional floor.
Adding Reinforcements
In some cases, the existing cement surface might be in such bad condition that it requires additional reinforcement. This can be achieved by incorporating fiberglass threads into the new concrete layer. Fiberglass reinforcement can significantly enhance the structural integrity of the new concrete, making it more durable and resistant to cracking and other forms of damage. This is particularly useful when dealing with floors that have large cracks.
When to Use Cement vs. Concrete
For light-duty applications, such as the self-serve car wash floors mentioned earlier, a 3-inch layer of new concrete is sufficient. This is generally the minimum thickness required for lighter loads and less demanding environments. Concrete with added reinforcement, such as fiberglass threads, is particularly suitable for surfaces with serious structural issues, as it can better withstand wear and tear.
However, for more demanding applications, such as driveways, patios, or commercial floors, a thicker layer of concrete is necessary. This is because these areas need to withstand heavier loads and more frequent foot traffic. A minimum of 6 inches of concrete is often recommended for such areas to ensure adequate strength and durability.
Conclusion
In summary, while it is possible to pour new cement over old cement in some circumstances, doing so may not always yield the best results. For optimal performance and longevity, it is often recommended to use concrete, especially when there is a need for strength and durability.
By understanding the differences between cement and concrete and the appropriate applications for each, you can make informed decisions about the most effective and efficient solutions for your construction needs. Whether it's a simple home improvement project or a more complex commercial renovation, choosing the right material can save time, money, and ensure a more satisfying and long-lasting outcome.