Foundation movement can affect the serviceability of a building. This may include water penetration through cracks and sloping floors. It can also result in distortion of door and window frames. This can be as an indirect result of movement in the external walls or directly through movement of the internal walls.
Such movement can take the form of ‘wracking’ where the frame loses its squareness (if that’s a word) and is demonstrated by tapered widening at one end of the gaps and a narrowing at the others. This results in the door jamming. The most common cause of doors jamming in older properties is normally temperature and moisture variations during the year.
This door frame in Cork City is about 20mm out of level!!!
But, interpretation of movement needs careful consideration. In this instance, it is evident that the top rail of the door and architrave have been significantly altered over a long period of time and this is disproportional to the cracking. This would suggest that the initial movement began quite some time ago, maybe when the building was constructed, and adjustments were made from or at that point.
Nonetheless, movement was rejuvenated for another reason thereafter and the result was a development of the original movement. This is demonstrated in the cracking. The weak points in the superstructure created during the settlement period will normally be the first to be compromised.
Therefore, it could be argued that the distortion in this situation represents both settlement and subsidence.