along with grading improvements, will stop the corner settlement. Then the cracks can be mor-tared.
Splash blocks can be knocked out of place, and dry wells can become blocked over time. I prefer to see solid, 4” PVC piping buried a few inches below the soil and extended to daylight at the edge of a landscape furrow or downhill from the build-ing. The downspouts can then be inserted into this piping to direct water away from the foundation wall.
Starting in the 1930s, most homes were built on poured concrete foundations. Shrinkage cracks are normal and quite common in concrete foundation walls and floor slabs. This type of crack is either vertical or diagonal, and radiates from wall open-ings such as windows or between floor penetra-tions such as beam-support columns. Cracks in concrete may widen in dry weather and become narrower when it’s humid. More serious cracks will increase in size over time.
Cracks are common in masonry because masonry products such as concrete and plaster are brittle and rigid, but are supported on materials that may not be equally rigid. Plaster walls are attached
to flexible wood structures, and foundations rest upon compressible soil. In addition, home com-ponents expand and contract with fluctuations in temperature as well as increases and decreases in relative humidity. Wood and other construction materials shrink when they lose moisture in dry weather, and expand in humid weather.
Walls and Ceilings
Ceiling cracks in buildings with plaster lath ceil-ings are quite typical. The cracks usually form be-cause the floor joists have sagged; building vibra-tions help to loosen the plaster bond to the lath, as