While the only true way to know why the floors above your crawlspace are sagging or sinking is to have it professionally inspected, I am going to outline a couple of the most common problems I see out in the field.
- Floors are bouncy - This usually is noticed when walking across a floor, you feel the floor shake or you see cabinets start to shake or make noise as you walk. This is usually a sign that the floor joists are under-sized or over spanned from the beam to the outside wall, or the floor joists are damaged from wood rot or termite damage. In either case, additional beam support is needed in the middle of the floor joist span to properly support the floor.
- Floors are sloping to the center of home - This is usually noticed when you walk from an outside wall to the center of the house. To know for sure, drop a marble along the outside wall and see if it rolls to the middle of the house. This is the result of some type of support problem with the center beam. The support columns or piers could have settled. The shims between the beam and column could have deteriorated or the beam itself could be deteriorating. Irregardless of the reason, the problem can be fixed. The beam can be raised and restored back to it's original position. This may requre a new beam, new piers, or new shims.
- Floors are separating from baseboard trim - While this can occur along any wall, the most common occurrence will be along the exterior perimeter walls. On the outside walls, this is most always a problem with the sill plate. Another sign of a problem is with windows and outside doors sticking. The sill plate or the end of the joist sitting on the plate is most likely rotting or damaged by termites. The most common repair would be to replace or sister the joist, lift the home, and replace the sill plate. This will usually always bring the home to it's original position and snug the floor up to the trim.
- Floors are wavy. - Unfortunately, this could possibly be several different problems. If you're lucky, it might only be that the center beam is over spanned between support piers causing it to sag up and down throughout the center of the home. This can be addressed by adding additional support piers or columns. On some occasions, the floor joists could be installed incorrectly with the crown of the joist up on one joist and down on the next. A couple of the joist could have had a knot in them and are now cracked causing a few of them to sag. Irregardless of whats causing this, we can repair your floors and bring them to their original position.
Thanks for reading the rambling thoughts of a crawlspace inspector,
Larry Ralph Jr.