Expert: Ted Barnhill (Principal, Design45 LLC) - 3/31/2008

Question
We purchased an older home in North Dakota that had two newer additions attached on opposite sides and one onto the back of the original home.  The house shifts terribly causing cracks in the sheetrock in the winter/spring.  The best evidence is the foundation around the double attached garage goes up a couple of inches each winter!  My husband believes the footings were not poured deep enough and there is nothing we can do about it that would be in our price range.  He is a very good weekend warrior and has done several construction and cement projects - just nothing like this.  Is there anything we would be able to do for a reasonable amount of money?

Answer
Heidi-

Wow!  You have a serious frost-heave problem.  In addition to the drywall cracking that you have noticed, be sure to look for problems at roof-wall and roof-roof joints between your garage/house or house/additions.  Also look at siding joints in these locations.  You want to be sure that you aren't allowing water to enter your structure.  Over time, water infiltration could become more costly that your foundation concerns.

As for the root cause of the problem, unfortunately your best solution would be to build deeper foundations for your garage, not an inexpensive solution.  Short of that, you could try to reduce or eliminate the frost heaving by:

1. Reducing the amount of ground water under your footings (it is freezing water that causes the heaving).  This may be as simple as adding gutters with adequate downspouts and leaders, or may involve substantial regrading to move water away from the building.  It is not always possible to redirect significant groundwater, but is worth a look.

2. Prevent the groundwater from freezing.  This involves insulating the ground from the air, such as in shallow frost-protected foundations.  You may find a local contractor with experience in this area who could recommend a specific retrofit installation for your problem, such as a skirt of rigid foam to limit penetration of frost around your garage.  Additionally, you could insulate the walls of your garage and heat it all winter.  I hate to recommend it as you may find this to be very energy-inefficient, but it may help prevent ground freezing.

Good luck, and feel free to post follow up questions.  -Ted

P.S.  I apologize for the delay in my response; I took the kids on Spring Break and forgot to turn on the autoresponder!