A House Is Only As Strong As Its Foundation

By Frank Ross
 

Ahhhh, Spring!  The change in seasons brings to mind flowers blooming, songbirds returning, warmer days and, yes, an unending list of chores including cleaning the house, cleaning the yard, and planting gardens. Before outside activities consume all your time, head to the basement and check something really important: the basement walls. Winter can be unkind to our built environment. Freeze/thaw cycles tear up our streets and winter rains beat on our home’s exterior. Those same forces are active underground, and they can inflict damage on the home’s structure. As winter temperatures freeze the ground, it swells and exerts force against the foundation wall. This pressure can fracture the wall, leading to possible serious damage to the home. Many times such structural failures remain hidden or go unnoticed, discovered only after a renovation project begins.

The first step in checking the foundation walls is to move everything away from them so you can see all sides, top to bottom. If the basement is finished very likely only an exterior check of the wall surface above grade will be possible. If you can see the exterior of the foundation wall then get in behind bushes and look closely at the foundation. Last summer I was doing just this and happened upon a wasp’s nest that was full of angry wasps. I did not get stung but moved away from them quickly!

What is the foundation type – stone, poured concrete, cinderblock or something else? As a general rule, stone is the best. It’s the most solid foundation you can have, but is usually only present in very old houses. When inspecting pioneer homes that are 100 years old or more, I am frequently asked by the agent and/or client about the seriousness of a certain crack in the foundation, which these old home tend to have. Being that I don’t have a crystal ball in my inspection tool bag I can only give my opinion from the forensic evidence I see. Most of the time the cracks are not a problem and sealing them is all that is recommended.

Poured concrete runs a close second to stone in strength. Look carefully for damage that can result in structural failure. Cracks are frequent in concrete foundations. Usually, vertical cracks are caused by shrinkage of the concrete as it cures. If you find a vertical crack, rub your fingers across it. If the surfaces on both sides are found to be even, the crack is most likely from shrinkage. This is rarely a structural concern. Uneven surfaces may be the result of the backfilling process.  Sometimes a backhoe operator in a hurry can cause this type of crack. Should you find moisture seeping in through the crack, contact a professional to repair the crack. Also if the width exceeds the thickness of a dime, seek repair.

Cinderblock walls are the most susceptible to problems. However, if properly installed and maintained, they tend to perform well. As with poured concrete walls, a vertical crack is rarely a concern. A segmented wall can still function adequately.  Once again, look for signs of water penetration, and if found contact a professional to repair the crack. A long horizontal crack, if found, is a critical issue. A horizontal crack compromises the integrity of the entire wall and can lead to catastrophic structural failure. If the crack is greater than the thickness of a dime or if the wall is bowed contact a structural engineer.

During an inspection if I find a small crack my advice to the client is to monitor the crack. Since soil conditions vary with the seasons, it will need to be checked several times over the course of a year.  If over the course of a year the crack never changes, then there is no cause for alarm.  If evidence of movement is observed, call in an engineer.  Many methods to repair foundation walls are available. Of course, they will vary in price depending on the labor involved.

So add this one item to your spring to-do list:  Check the foundation for cracks. If you find a crack in the basement wall, check it regularly, and if you are at all suspicious of it moving, call an expert to evaluate and/or repair it.

Frank Ross is a Certified Utah Home Inspector for Pillar to Post Professional Home Inspection and a full member of the National Association of Certified Home Inspectors.  Readers may contact Mr. Ross at (435) 867-6400 or frank.ross@pillartopost.com.  You can learn more about Pillar To Post Professional Home Inspection at www.pillarposthomeinspection.com