Q: I have a home from the early 1970s, and over the years the garage floor has settled about 2 inches. I can still use the garage, but the stairs to the house have also settled. I cut pieces of plywood to cover the steps to raise them back to what they used to be. I'm now trying to sell my home, and a contractor friend told me the stairs might be a problem because they're uneven. Are there any rules covering a home this old? How can I fix the problem?

Q: I have a home from the early 1970s, and over the years the garage floor has settled about 2 inches. I can still use the garage, but the stairs to the house have also settled. I cut pieces of plywood to cover the steps to raise them back to what they used to be. I'm now trying to sell my home, and a contractor friend told me the stairs might be a problem because they're uneven. Are there any rules covering a home this old? How can I fix the problem?


A: When steps are uneven in height, there is the possibility of tripping and falling, even if there is a handrail available. Information from the Office of Statistics and Programming, National Center for Injury Prevention and Control, U.S. Centers for Disease Control and Prevention, estimates that, in 2007, there were more than 8 million nonfatal injuries caused by unintentional falls in the United States. There was no indication as to how many of these falls were on stairs because falls from ladders, stepstools and tripping are included in these statistics.


Data included on nonfatal falling injuries in a chart from the CDC can be found at: www.cdc.gov/ncipc/wisqars/nonfatal/quickpicks/quickpicks_2007/unintall.htm.


The height of each step is extremely important in preventing tripping and falling. The earliest code books called for steps to have even risers with a maximum of 3/8 of an inch difference between the risers over the entire length of the stairs. When the risers are uneven, people tend to either trip at the higher riser when ascending the stairs or stomp down hard on the lower risers when descending the stairs.


To give you some idea of why stair risers need to be equal in height, try walking up a flight of stairs with one shoe on and one shoe off, making sure you have a good grip on the handrail when trying this experiment. Just the difference in the height of the shoe can cause tripping.


If your home is inspected by a certified American Society of Home Inspectors inspector, the stairs will be an issue in the sale of the home. If the stair risers cannot be made even by adding plywood spacers, then total replacement should be considered. An experienced carpenter can construct a set of wood stairs for the garage, making sure that stairs with three or more risers also have a handrail on one side of the steps.


The maximum height of each riser should be 8 inches, and the depth of the treads should be 10 inches. Measure the distance from the door's threshold to the garage floor and divide that number by eight. This will give you the number of risers required for your garage. You can then adjust the numbers to make each riser the same height.


Also, make sure the door from the house to the garage does not open out over the steps. When a door opens over a stair there has to be a 3- by 3-foot landing for the stairs. Sometimes, when room in the garage is limited, it may be easier to re-hang the door so that it opens inward and the landing can be eliminated.


Dwight Barnett is a certified master inspector with the American Society of Home Inspectors. Write to him with home improvement questions at C. Dwight Barnett, Evansville Courier & Press, P.O. Box 268, Evansville, IN 47702 or email him at d.Barnett@insightbb.com.