How Foundation Cracks are Sealed


You have some cracks in your foundation and need to know what you will have to do to get them fixed. The first thing that should be done is to contact a qualified foundation specialist to assess the damage and get it repaired first. The severity of the cracks will determine the steps that will be taken.

Preparing the Surface

If the foundation cracks are not too severe and you feel you can fill them yourself, you will want to follow these steps to prepare the surface:

  • Clear the area that is in front of the cracks (such as grass, tree limbs, bushes and plants), to make room to work and to allow you to be able to examine the damage up close.
  • Next, you will need to carefully clean out debris or materials that are wedged or hanging in or off the cracked area. Some of the things that you can use to do this include; soft or wire brushes, tools such as a screwdriver, or a small putty knife. The use of an air compressor can also be utilized in place of the above devices and can be somewhat more effective and easier at getting the debris out of the area.
  • Widening the cracked area just a little bit can also help in the repair process, which can be achieved by using a hammer and a small chisel. You want to be able to give the sealant something to adhere to, by roughing up the edges.
  • When you have gotten the area free of debris and have opened it up slightly, you will need to thoroughly clean the opening with your brush and then wet it down with some water to make sure no more debris will come off, so that it will not mess up your covering. Make sure to dry the area that you have dampened before proceeding.

Sealant Application

Now that the surface of your foundation is cleaned you can begin to apply the adhesive into the crack. Some of the sealants that can be used are:

  • Epoxy putty
  • Vinyl concrete patching compound
  • Cement mixture
  • Hydraulic cement
  • Caulking – It can be composed of either: latex concrete, polyurethane or silicone
  • Waterproof sealer for masonry (this is a product that you use at the end)

When you are filling in space and using any of the sealants listed above, you can apply with a variety of tools (except for the caulking, as you will need a caulking gun). Some of the tools that can be used are a putty knife, trowel, float, and paint brushes. You can as well use a baker’s cone to fill the cement into the crack to reach a deeper depth.

If dealing with fractures that are a half-inch wide and or deep, you can place a foam backer rod into the void and then apply a concrete caulk mixture. Backer rods help to fill the cavity and give something behind your application.

With any of the applications, you will need to make sure that the opening is filled in and you will also need to level off the outer side of the foundation. Make sure anything that you apply is allowed to completely dry before reapplying or repainting. Whatever you choose, you need to make sure to follow the instructions entirely for the best outcome. Some of the above products require a certain thickness on the surface to seal the crack properly.

If you have cracks that are all the way through your foundation's wall, it is best to have a professional contractor fix the problem. They will have the necessary equipment and sealants to make sure that you will not have any intrusion issues.

You should always make sure to look over your entire foundation for any signs that there could be a problem. If you do have any issues, you need to find out what is causing the fracturing in the foundation in the first place. There are many different reasons for cracks to present themselves, such as settling, root intrusion, drought problems, and many more.

Even though you might have some cracks in your foundation, it is not out of your reach (so to speak) to be able to fix it on your own. If you need any help or information, contact a professional and they will be glad to help you from start to finish.

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