My husband is a custom home builder. He has been having a lot of problems with the large crown moulding he puts in his homes. In most of the homes that he has built, once he returns to them about a month after the people have moved in, the moulding has separted from the wall. He has started putting humidifiers in to the homes because most heat with gas. Is there anything that he can do when installing the crown moulding to prevent this?