There are a number of indications to damaged foundations and as we have discussed in detail in previous posts, they are often manifest in the walls. Cracks and other signs of structural damage are also good indicators, you should be aware of them, and not take certain types of cracks easily. There are, however other signs that you can look for in walls that are not exactly signs of foundation cracks.
Perfect wall rotation is a rare sight, more often than not, it will leave a large crack right across the wall. Apart from its alarming implications, it is a rather fascinating occurrence. When there is a heaving or a settling incident, that is even and affecting the house on an angle that is diagonal or perpendicular to the foundation and a corresponding wall, the entire wall, as one large piece may shift. It normally happens to internal walls, if the turning point of the wall is close to the center of mass of the wall it may have a rotational movement. When it happens, the wall will move on its axis, if it had one, and move out by a few inches. When seen from one side it will have moved inward and the other side of the wall will move outward. A rotated wall will normally take the edge out and its joint with the adjacent wall will give out. If there is a door frame or a window or even a ventilation shaft on either end of the wall, it will be moved along with the wall, making the shift even more visible.
It may be a serious issue
If you notice such a movement in any of your walls, make sure to act fast and get a contractor who works with foundation cracks to have a look at it. The sooner it is caught, the easier it will be to reduce the effect and damages to your structure. It may even be possible to reverse it to an extent. Only a professional can gauge those possibilities.
The whole wall moving out like a swiveling secret entrance is the less likely situation. In most cases, the wall will split or crack a large portion of the plaster and peel off the outer layer of paint with it. It cannot and should not be ignored, so when you see or sense something like this, you know what is happening.