Answer:
Most of the problems are caused by indirect joints between the exterior walls (especially in exposed beam areas), or by poor waterproofing or construction techniques.
(1) Because the time required for the second layer of the exterior wall structure to be poured over the first layer is usually more than 15 days, it is easy for the bonding strength and water tightness to be poor due to the accumulation of dust and debris.
(2) When pouring concrete, the upper structure often experiences honeycomb formation due to insufficient compaction pressure.
(3) When painting the exterior wall, it is often the case that due to sloppy workmanship, the remnants of template scraps, iron wire, etc. left in the seams are not removed beforehand, resulting in sloppy construction.