SAGGING FLOOR REPAIR
A common cause of interior drywall cracking is floor sag. A common cause of floor sag is inadequate support beneath load-bearing walls or heavy room partition walls. Another cause is over-spanned floor joists or main beams. As the floor sags, doors will rack and cracks will form above the doors. The effects can even cause the roof/ceiling to sag. Typical repairs include jacking the floor back to level then constructing new beams and foundation piers beneath the floor system or reinforcing the floor system with sistered-beams/joists.