Whether drywall, plaster or concrete, walls are susceptible to cracks. Even walls in newly-built homes are prone to cracks, which normally occur from settling. Homes are constantly settling as different construction materials expand and contract at different rates. Fluctuating humidity levels, soil movement and shallow foundations are typically responsible for settling, which may result in cracks in the ceiling or walls. Although generally a cracked wall is nothing to worry about, certain cracks indicate serious structural damage. Regularly inspect cracks above door frames and in walls for certain signs to determine whether the cracks require professional attention.
Plaster and Drywall Cracks
Analyze the direction of the crack. Vertical and horizontal cracks in drywall or plaster walls typically indicate drying and shrinkage, which is normal after construction. Jagged cracks, stair-step cracks and 45-degree angle cracks generally signify structural movement or settling issues that are occasionally serious but usually harmless.
Measure the width of cracks with measuring tape. Typically, wider cracks signify more serious issues than thinner cracks. Cracks less than 1/8-inch thick are considered stress cracks and are harmless, while cracks 1/4-inch wide and larger are often more serious.
Inspect the position of the crack after measuring its width. Long, horizontal cracks that extend along the joints where interior partition walls and upstairs ceilings connect generally signify roof truss issues, which cause ceilings to detach from walls. These cracks are serious and require professional attention. Small cracks located above interior windows or doors are usually harmless.
Check whether water is leaking into the crack. If drywall or plaster surrounding the crack feels damp, you may have a water infiltration issue. Never take chances with cracks that leak because these are sometimes serious.
Study the direction of the crack to determine its seriousness. Vertical and diagonal cracks in concrete walls typically indicate foundation movement. If a vertical crack widens at the top or bottom, the wall is either settling or gradually heaving, which may present serious issues. Stair-step cracks may also signify heaving. Horizontal cracks in concrete walls, however, indicate poor wall designs or pressure buildup behind the wall. Concrete walls containing horizontal cracks are serious issues.
Measure the width of cracks with measuring tape. Cracks less than 1/8-inch wide are likely stress cracks, while larger ones are often more serious.
Inspect the position of the crack after measuring its width. Short, thin cracks around windows are typically harmless and require no attention. Stair-step cracks that start at the corners of windows or doors generally signify that foundations are either settling or heaving and may present serious issues.
Check whether water is leaking into the crack. If the concrete surrounding the crack feels damp or contains white powdery stains, you may have a water infiltration issue. Leaking cracks in concrete require immediate attention.
How to Handle Serious Cracks
If you notice any cracks that you cannot classify or believe may be serious, it is best to hire a structural engineer to inspect them. Any crack that rapidly widens, expands in length or changes in any other way could present serious issues. Do not attempt to repair these serious cracks without first speaking with a professional.