There are cracks between the frame and the wall: aluminum alloy doors and windows installation process, many winter sliding door aluminium sealing workers due to rush or jerry-built, did not do a good job of sealing between the door frame, window frame and the wall. 

Especially in the old room, the wall loosens in the settlement process, and the closeness between the aluminum alloy door and window frame is reduced.  If the waterproof glue is not evenly coated, the sealant is not enough, or the expansion bolt is not nailed, it will make the frame body and the wall can not be "tight".  In the summer rain weather easy glue collapse, autumn and winter season is caused by air leakage.