In the mid-twentieth century, the concrete industry adopted new techniques to enhance the strength of foundations. The prestressing was adopted as an innovation to enhance the strength of concrete. In 1969, the Federal Housing Administration officially accepted this type of foundation. Later on, the post-tension foundation gained popularity among the builders.
How Post Tension Slabs are Formed?
Post-tension slabs contain a steel cable that runs in a crisscross way throughout the center of the slab. The steel cable comes with a covering due to which it can move even inside the concrete to get stretched. Once the concrete dries, the high-strength steel cables are stretched and anchored. Post-tension slabs have trenches filled with concrete that enhance its structural integrity. Only the experts can go through the stretching procedure, as it is not much easier to stretch the cables through a slab.
Pros and Cons of Post-Tension Foundation
Pros:
- Post-tension slabs are thinner but strong.Â
- A foundation with a post-tension slab requires less concrete.
- These slabs are efficient in poor soil conditions.
- These slabs are easier to inspect and can be repaired.
- These provide a better resistance to the seismic activities.
Cons:
- Crack control is not easier at the initial stage when cables are stretched in concrete.
- Skilled labor is required to install it.
- It’s very tricky to repair these slabs.
- The post-tension slab system can be complicated if you have to go for future expansions.
- The drilling in these slabs is not recommended.
Post Tension vs Rebar Foundation: Which One is Better
Both post-tension and rebar foundation have their own pros and cons. One must choose the slab method according to the type of building being constructed, the nature of the soil, and seismic activities.
In areas where soil is expansive, it is recommended to have post-tension foundations.
In comparison, if we look at the durability of these slabs, the life of a post-tension slab is 15-20 years and these are likely to fail after a certain period. Meanwhile, the rebar concrete slabs can last for much longer.
Can Post-Tension Slabs Fail?
There are some factors that can cause the failure of post-tension slabs such factors are:
Suppose the weight distribution of the building is uneven. The uneven pressure on the slab can cause cracking in the building.
If the thickness of the soil is not uniform under the post-tension slab, then the support to slab will be compromised, and it will lead to failure.
Conclusion
The post-tension foundations, despite their benefits, are likely to fail earlier. But the builders prefer to choose this option as it is cost efficient. On the other hand the conventional slabs provide the best structural strength to a building.
Anyhow, if you are dealing with any issue either with the post-tension slab foundation or rebar foundation, contact us to get it inspected and suggest the most practicable solution to improve the structural integrity of your home.
