Thermic setting in (big) buildings
All buildings big or small have to deal with a differential thermic setting between winter and summer. The thermal shrink of concrete is 1/100 mm/m/°C (The hygrometric expansion of bricks εr < 0,1mm/m); this means that the shrinkage cracks can be repaired or evaluated definitively after a (strong) winter. A building of 20m will undergo a theoretic, thermal setting of 20 x 0,01 x 50 = 10mm.
A part of the shrink will be absorbed by the construction materials themselves, a part will translate into the “working” of hairline cracks. With a bigger building the dilatation joints will “cut” through the building to absorb extreme pulling forces because of thermal shrink. The joint of a building extension will translate differently than a solid building. The final evaluation of the (hairline) cracks can be correctly assessed after a strong winter. Also the recently fixed leaks in big concrete constructions can be pulled open again during or after a strong winter. You can best keep this in mind so you don’t have to pay twice.