James from West St. Paul asks:
You put in our driveway about 12 years ago and we could not be more pleased with how nice it still looks. This winter, some of the squares have lifted up or others have dropped. Is this normal and if so what can we do? I keep hitting the edge when I’m shoveling snow.
Mike Therres, Vice President at LCM Concrete Says:
Hi James I feel your pain.Where my driveway meets the garage floor, the driveway is approximately 1” above the garage floor. This is caused by the frost under the driveway, and is referred to as “frost heave” in the industry. When the moisture in the soil freezes, it expands as all water does. This expansion pushes up against the concrete slab and raises it. Frost heave is fairly typical in our weather climate. In many cases the slab will settle back down after the frost leaves the ground and return to its original position. When you see a new road or highway being built you may notice the contractor has dug down what seems to be pretty deep. What they are doing is removing the soil that can cause frost heave, and installing material that in most cases eliminates this problem. Sometimes the contractor digs down as much as 4’, or possibly deeper. For example where I live we have mostly clay which holds water very well. Other types of earth such as sand is able to drain the water much easier. The more water held in the soil, the worse the frost heave gets. Removing and replacing the soil is usually not practiced for residential concrete work, as the cost becomes prohibitive. However, if frost heave is causing problems around a door or siding there are other things that can be done to help eliminate the problem. It is important for a concrete contractor to know if this could be an issue when we are estimating a project in order to do what is best for the homeowner. At LCM we have over 30 years of experience in dealing with frost heave and take careful measures to avoid the problems frost heave can cause.