How Do You Know if a Building Has a Post Tension Slab?

A post tension slab is s concrete slab that has structural steel cables running through it. This makes the concrete stronger without actually reinforcing it and helps to reduce the cracking of the concrete slab.

So how do you define post tension slabs? These are flat slabs of concrete to make it stronger and making the concrete in compression.

It can be made longer due to pre-stress keeping the concrete in compression.

This gives a lot of minimization to the materials being used without compromising on the structural strength of the steel.

It also reduces the budget and increases the structural stability of your house.

What are the benefits of making a post tension slab?

There are many benefits of using post tension slabs.

These summarized for you below-

Enhanced fire resistance capabilities

Reduction in the cost due to lesser materials required

Reduction in use of materials

A highly robust and durable solution

Minimal deliveries

Enhanced thermal mass capabilities

Faster installation time

How do you know that a home has post tension?

Generally, if you go in a home that has a post tension slab in place using a hollow hydraulic cylinder this would be indicated using a sign that is in the garage door. It is often placed near the edge of the garage door to ensure that it comes insight.

Generally, in the older homes, you will find that there is a plastic or paper sign that has been fastened on the wall. It is always placed right next to a garage door that goes into the house.

At times, there can also be no visual clues to obtain that no hollow hydraulic cylinder has been used for it.

But to get the evidence that post tension slabs are present beneath the floors all you got to do is check around the house for circle stamps on the soil. You will find them to be at least one to one and a half feet and three inches wide.

And there are loads of them around the house as you can see them every few feet apart. These indicate the ending of the post tension cables.

This can also be made invisible due to the landscape around the house or by using cone shaped voids that blend into the soil.

Why builders might opt for a post tension slab?

As we told you above that the post tension concrete slabs have one major purpose and that is to get a reduction in the overall cost of laying down a strong structural foundation.

But this is only one of the reasons with the other one being the type of soil in the area.

Let’s get to know how the soil beneath the ground can be the cause of laying down these post tension slabs using a hollow hydraulic cylinder instead.

What happens is that sometimes the soil in the ground is unstable and due to this if a normal foundation is laid out then this would normally sink.

The primary reason for this is the shrinkage in the soil that is a result of a lack of moisture.

What happens is that some of the soil types tend to lose moisture faster. The loss of moisture will result in a shrinking of the soil.

This will sink the foundation of the building of the house.

As the shrinking of the soil during the hot summers or the drought season due to loss of moisture is not even along some parts of the foundation of the building might sink in more than the other ones.

This can give a real structural instability if the house in case of a natural disaster such as a flood or an earthquake.

As a result of this, the building might need to be replaced with a post tension slab using a hollow hydraulic cylinder.

Sometimes the piers are used instead of a post tension slab.

Piers are yet another economical way of replacing damaged sections of the foundation. For this purpose steel piers, drilled piers, or concrete piers are generally used.

But anyways using a post tension slab is a much better option than using piers as this can be structurally stronger and crack less under immense pressure.

What does the signage indicate?

As we have already told you above that in the old houses sometimes where the use of post tension slabs have been done underneath the ground that is not visible generally will have a clear indication warning with something like this written-

“Post tension slab underneath. Do not cut or core”

So what does this message indicate? How should someone react to this if they don’t have any knowledge of a structural post tension slab?

This message is to warn the user that the post tension cables are underneath the ground. Cutting or drilling of a concrete slab might result in one or more of the structural steel cables being damaged.

Of course, now that you know this does not even need to mention that this will make the structural post tension slab weaker.

One of the even worst consequences can be ripping off one of the cables of the post tension slab and this can easily injure someone.

Thus the slabs have always this warning engraved to warn anyone.

Final thoughts

If you need to hire an engineer or a structural design architect for post tension slabs in your house then find out the leading experts who can give you the best solutions.