Home buyers wary of potential problem with garage

ShareThis

Q: My husband and I found a house we both really want -- brick with a block foundation. Although the house has a partial basement, the kitchen and a bath are over a shallow crawl space with a small entry. My husband had a look at the crawl space.Where the garage attaches to the house, about 12 feet of block were missing, replaced with plywood nailed at top to the floor joist and anchored to the ground with stakes. The shocker is that across that space, and tapering 3 to 4 feet into the garage, the ground has washed out from under the concrete garage floor and away from the stakes.This damage had to have occurred several years ago. There is some dampness in that area, but nothing visible to explain how this could have happened. It's as if the problem started underground, but there are no mains in that area. We have come up with a fix for the hollow space under the garage floor, but feel we should know the cause.The present owner bought the house as a foreclosure six years ago; her inspection did not turn up this problem. But I doubt that anyone crawled into the space through the small entry.Should we run? Have it inspected before we make an offer? -- D.H., Kankakee, Ill.A: The plywood was probably a form for the garage's concrete footing, which was poured to match the contours of the original slope of the lot when the home was built. The 3- to 4-foot area where the soil appears to have washed away is most likely a load-bearing concrete lintel (looks like three or more concrete blocks put together).A lintel is used where a steel or wood beam is not practical because the soil contact would rust or decay the structural supports. The lintel supports the loads of the floor joists, the walls of the home, the roof and the exterior brick veneer.The garage footing is shallow, 24 to 40 inches below grade, while the basement footing is 6 to 8 feet below grade. The lintel is used to tie the garage footing to the basement foundation wall while spanning the 2-foot gap behind the basement foundation wall and the garage-foundation footing.Otherwise, the garage floor would be even with the basement floor or the garage would have to be filled with tons of gravel to bring its floor up to the grade level of the front yard.Once the home was finished, the open area under the lintel was filled from the outside with dirt or gravel, and the fill would settle or slide until it reached a 45-degree angle; then it stops sliding. Do not run from the purchase just yet, but it is very important to have the home inspected by a qualified home-inspection professional.That crawl space needs to be accessible for repairs to the plumbing and for inspections of the floor system for decay or infestation. There should be an 18-inch clearance between the bottom of the floor joists and the crawl-space soils.The soil under the home then needs to be totally covered with a 6-mil-thick vapor barrier. This can be an expensive repair, but it is necessary.(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 286, Evansville, Ind. 47702.)