In my last blog, I discussed how to interpret signs of stress for settlement or heave. In particular walls doors and windows. Continuing in that line of thinking, I would like to highlight a few more common signs of stress.
Above is a picture of a ceiling as it intersects with an interior wall. The pattern seen is referred to as cupping. It happens usually when the interior wall is pushed up into the ceiling where above it the bottom of the trusses are suspended. The drywall pushes up more easily where it only meets the drywall from the ceiling and cannot push up where the bottom of the trusses resists it.
Alternatively cupping signs could also be albeit rarely, be caused by downward movement of a perimeter wall.
We regularly see cracks in the corners where interior walls meet the perimeter walls. See below.
This is clearly caused when interior walls are moving differently than perimeter walls. See the illustration below:
This is usually caused by upward movement of interior walls in the middle areas. As that wall holds its rectangular shape and moves up on the end away from the wall, where it meets the perimeter wall it starts to pull away at the bottom.
Alternatively and more rarely, if the outside wall footing settles, it can pull away from interior walls.
Other clues to watch are if there are gaps under the baseboards or if they are crammed (the floor pushing them up from below).
- Cupping of trusses usually means heaving of interior walls, (hence heaving of the floor slabs)
- Corner cracks between interior and perimeter walls usually means heaving of interior walls and floors
- Cramming of baseboards usually means floor heaving