Without a sound foundation, nothing on top of it will have any stability. However, the method of building a foundation can dictate its longevity and susceptibility to damage. While steel rebar has represented the conventional means to reinforce foundation concrete, post tensioning has grown in popularity. But which solution will work best for a new home?
The Main Differences between Rebar and Post Tensioning
Rebar, or reinforcing bars, represents the traditional pre-stress, pre-tensioning method of building a foundation. Contractors will pretension the rebar then cast the concrete. Once the concrete hardens, the tension is released, which transfers stress to the concrete.
Rebar typically comes in the form of steel bars or a mesh. They're easier to work with for some applications, and are easier to implement. That's because they've remained the de facto way of putting together a foundation for a long time.
Post tensioning makes use of steel cables. The cables have no tension when you pour the concrete over them. The tensioning comes into play after the concrete hardens. This allows the concrete to remain more compressed with less stress on it. Because of that, it's possible to use thinner slabs of concrete, while maintaining strength.
The main difference between the two methods has to do with how much compression and tension the concrete will have in the end. Forces that can move or add pressure to your foundation should idly have to overcome the concrete's compression before pressure or tension becomes a factor. At the same time, the concrete needs to handle stress from the structure that will come together on top of it.
Location and Soil Type Matters
Places with expansive soil types often fare better with post tensioning. Having a soil test done can help to determine which type of foundation construction will work best. Foundations typically contact soil, not underlying bedrock. So it plays an important role in foundation construction.
Which Technique is the Superior One for Home Foundations?
You may hear one technique has superiority over another. In truth, there's far more variables that go into creating a viable foundation. You may even hear one method costs more than another. Once again, there's variables. Where you're building, the underlying soil type, and where you source the labor and materials can affect the prices of both methods a great deal.
If post-tensioning interests you, it's very important you speak with contractors who have a history of creating post-tensioned foundations. While many contractors can put together a rebarred foundation, post-tension construction requires specialized training and a high attention to details.