Slab Inspections

Everything You Need To Know About Slab Inspections

Having a slab inspection is vital to making sure your home is set up the right way. You don’t want to have your builder put up the entire structure without getting one.

A slab inspection is a visual inspection of the builder’s preparations before the structure is fully finished. It is usually done in the afternoon before the concrete is poured and checks the footers, reinforced steel, plumbing, and polyvinyl membranes for any tearing.

Getting your foundation set without a slab inspection could cause several long-term problems costing you a significant amount of money. Make sure to read through this article to get a good understanding of what a slab inspection actually is.

What Exactly Goes into A Pre-Slab Inspection?

When a builder has set up your foundation and is ready to pour the concrete, you want to make sure their work has been double-checked. And you want this person to be a third party so that your builder does not purposefully neglect any changes that need to be made to speed up the process. If you can, try to get the pre-slab inspection done the same day as when the concrete is poured so that there are no delays or additional costs you must incur. The inspector will usually coordinate with the builder and keep you updated on the progress so that you don’t have to set up the inspection yourself. You want to make sure when getting a slab inspection that there is no rain, and the temperature is below 95 degrees Fahrenheit for optimal concrete pouring.

We will go into detail about the main components of a slab inspection, but before we do, below are some examples of what an inspector is looking for.

● Undersized materials
● Incorrectly placed materials
● Missing pads, beams, and footings
● Omissions or left out materials
● Poor building practices
● Lack of termite protection
● Damaged vapor barrier membrane

Concrete Forms

Foam Boards and Bracing Support Hold Concrete Together

When a pre-slab inspection is done, one of the first things that are checked is the foam boards. The foam boards are also held together with bracing support, and both of these pieces are crucial to making sure the concrete is held in place. If there is a break in the bracing support or holes in the foam boards, your concrete could spill out or crack over time. Your pre-slab inspection will ensure your bracing support systems and foam boards are in proper shape for the foundation to be poured.

Checking the Footer Width And Cleanliness

The concrete is going to be poured into your footers, which means that when doing the pre-slab inspection, your third party will need to check the width. This is because the structure that is going to be built needs to be able to sit on top of the footers and concrete. If the footers aren’t large enough, then your structure will not hold, and you will need to have your builder redo the footer width. The inspection will also need to check the footers’ cleanliness to make sure there isn’t any dirt or debris inside. If there is any foreign material besides concrete, it might compromise the integrity and cause long term issues with your foundation.

Making Sure Reinforced Steel or Cables Are Supportive

The foundation alone will not be enough to hold the structure you are building, so additional reinforced steel or cables are used. They need to be suitably placed to provide a necessary complement to the foundation concrete. When the inspection is being done, they will look closely to make sure the foundation is going to have the support it needs using the reinforced steel or cables. Without the steel or cables set up properly, your foundational concrete can have cracked or shifting issues when the ground underneath starts to move due to natural reasons.


Inspecting the Plumbing

The last thing you want when your house is built is to have problems with the plumbing. This can not only be a costly expense, but it can also be a long-term issue for your home. When a pre-slab inspection is done on your home, the inspector will check on your plumbing to make sure that it is completed before the foundation is poured. The inspector will also make sure that the plumbing is supported properly and that it has been water tested, which is required before building.

Inspecting the Polyvinyl Membranes For Tearing

Polyvinyl membranes are the PVC that is used in the home building because it is relatively inexpensive. Inspectors will need to look at the membranes to makes sure there is no tearing and that it has been completed correctly. If a problem occurs with the PVC membranes, you can have this replaced, and it won’t cause nearly as many issues as having a problem with your plumbing or footers.

Finishing Up A Pre-Slab Inspection

Because the inspections are done the same day as the foundation's pouring, the inspectors will usually give a verbal acknowledgment if there are no major issues. Later, you will receive the full report that will include pictures the inspector took as well as a written part of your report. If there are major issues with the way your builder has set up your home, then you will need to delay the pouring of the concrete. You will need to have your builder fix any of the issues and have an inspector come out again in order to ensure everything has been taken care of.

Slab Problems to Look For When Buying

cracked foundation

Because a lot of problems with building a slab incorrectly only present themselves after years of wear and tear, it’s important you know what to look for. Before you buy your next home try and check for these common issues of a bad foundation, so you don’t get yourself into a terrible investment.

Finding Cracks in The Concrete

One of the most common places to find slab problems in a home is the garage area. This is because most of the other parts of the house are covered with wood or carpet, and you can’t actually see the foundation. Most garages will incur cracks because of dropping hard objects or constant wear from cars weighing on the concrete. But large cracks in your concrete are telltale signs that there is something bigger happening with how the foundation was actually set up. On top of that, the cracks can allow moisture or termites to enter the home at vulnerable places and can be a sign of subsidence. If there is subsidence, there won't be much you can do about fixing the foundation, and it can be a highly significant investment.

Upheaval Can Raise the Foundation

Foundation upheaval is when the foundation of a home begins to rise upwards and can cause easily identifiable issues. The main reason for a foundation to start raising is because there is too much moisture in the soil due to rain. But if there is a plumbing leak underneath your slab, this will also be a cause for upheaval. Another reason why having the pre-slab inspection is so important because your inspector will check for all plumbing issues.

Frost can be another reason why soil will expand, causing upheaval in your foundation. You can notice upheaval in your home because the doors will begin to stick as they open and close or fireplaces that began to rise higher than normal over a period of time. If your home rests on clay soil, it has a greater chance at upheaval because this type of soil will expand and gain volume more than other types when wet.

Sinking Foundations Cause Slab Problems

Sinking foundations or “settling” foundations is when the ground begins to lower where your foundation lies. You can literally see this process happen over time as one side of the home begins to appear lower than another or the middle of a home sinks lower than the perimeter of the home. The cause of a settling home is because of the amount of moisture on one side of the home as opposed to the other. The more moisture in the soil, the more lifted the house will be on that side. If rain tends to drain to a specific area of your home, you will find that area to stay maintained.

You don’t want to have your home sink any more than 1-½”; and you will want to address the issue as quickly as possible. Leaving your home to settle more than the recommended amount can cause a need to install interior foundational piers. Installing these piers will require cracking the slab foundation and can cause quite a mess in your home.

Doors Have Problems Opening and Closing

Whether you are having trouble with upheaval or settling, a good sign to watch out for is doors that are having trouble opening and closing. Humidity can also be a source of sticking doors after heavy rain or flooding, but if your doors continue to have this issue over a longer period of time, there’s a bigger problem. You’ll notice that the door will be higher on one side of your doorway than others for any exterior doors. French doors or other double doors will have issues closing in the middle fully when suffering from upheaval or settling.

You’ll Notice Gaps Around Window Frames

When looking for signs of your foundation shifting, it's essential to perform a visual search of your window frames. If there is a significant amount of upheaval or settling, then you will notice gaps at the edges of the window frames. This can allow air to flow freely from outside and inside your home. This will have a significant impact on the home’s ability to retain heat or cold. You can experience very high utility bills from needing to run your central AC or heat in your home significantly more than other homes that are not suffering from the same problems.

Counters Can Separate from The Walls

When the foundation of your home starts shifting everything inside the home starts shifting as well. And if you don’t have straight walls, then everything attached to those walls can start to come undone. If you have noticed your cabinets reaching the point where they are ½” away from the walls, then you have a serious problem that needs adjustment.

Before purchasing a new home, make sure you are checking how attached the cabinets are to the walls. You also want to notice if there is a significant amount of calk around the cabinets where someone is trying to hide the fact that there is a significant gap.

What Happens When You Have Foundation Issues?

If you believe that your home could be suffering from foundation issues, you will need to contact a foundation specialist as soon as possible. The longer your foundation is left on its own, the more expensive your problem could be. Usually, an evaluation of your current foundation will be free, and the inspector will give you a quote in writing on how much a repair might cost. You want to try and hire a company that offers a slab foundation warranty, and if you can find a transferable lifetime warranty this would be the ideal situation.

The contractor will try to match the original level of your home, which is usually referred to as house leveling or foundation leveling. When a house leveling job is being conducted, a team will raise your home and install structural supports known as foundation piers or pilings. The foundation will then rest on these piers to get back to a level surface.

Steel Piers vs. Concrete Piers

There is a choice between what material a contractor chooses for the piers or pilings. They can choose between steel or concrete, and both will provide similar support. The major difference is that steel supports can be installed further into the ground to find more solid material to rest on. Because concrete cannot be installed to as much depth, there is a chance it will not hold as well as steel over a long period of time. Since most foundation issues don’t require piers to be installed to the 35’ depth that steel is capable of, it is usually more cost-efficient to install concrete. The contractor will determine the number of piers needed in order to level your foundation and home, and the more you need the more expensive the cost.


Getting a slab inspection before building a home is absolutely essential to ensuring your foundation has been built properly, and you won't suffer any long-term damages. If you are buying a new home, you will want to check for slab foundation issues so that you won’t be held responsible for expensive repairs.