Planning a room remodel might require adding partition walls.
Fastening a new wall frame to an existing house frame doesn't necessarily require removal of the existing wall and ceiling coverings. The new wall must fasten securely to the framing on the ceiling, the walls and the floor. When that is accomplished without removing the drywall, it reduces work and makes the installation easier and less expensive.
Wall Framing
Partition walls divide space into separate rooms. The frame consists of studs, usually set 16 or 24 inches apart, between a top and bottom plate. A partition wall does not support any weight, and removing the drywall is not necessary.
Weight-bearing walls have two top plates instead of one, and help support the house. Never install weight-bearing walls without removing the drywall, since drywall is unsuitable for supporting a load. You would encounter this situation if moving a weight-bearing wall a short distance.
Anchoring Walls
The drywall that sheaths a wall will crack at the joints between the wall and ceiling and between adjoining walls if the wall can move. Anchoring the wall to the floor, the ceiling and adjoining walls prevents movement. A wall anchored to the floor and adjoining walls will still flex along the ceiling unless it is anchored to the joists.
If the partition wall is easily fastened to the ceiling joists, such as when the joists are perpendicular to the wall or a joist runs parallel and directly over the wall, there's no need to remove the drywall. Anchor the wall's top plate to the ceiling joists with 3 1/2-inch wood screws or 16d framing nails.
Perpendicular Joists
Partition walls are usually framed laying flat on the floor, rather than standing up. Anchoring the wall to perpendicular joists is easy. Once the wall frame is complete, the frame is stood up, plumbed with a level and fastened to the floor, the adjoining walls and ceiling joists. A stud finder will locate the ceiling joists for placement of the nails or screws that anchor the wall to the ceiling without removing the drywall.
Parallel Joists
Parallel joists can present a problem. Either the wall frame must sit directly under a joist so the wall fastens to the joist, or framing between joists is necessary for anchoring the wall to the ceiling. If the ceiling joists are not located exactly where you want the wall, shifting the wall location 8 to 12 inches in either direction to sit under a joist is one remedy. Removing the ceiling drywall and adding blocks between the joists for anchoring the wall frame is another. The choice is based on your preference -- either altering the position of the wall or tearing down the existing drywall to add the blocks between the joists.
Tags: ceiling joists, adjoining walls, , , wall frame, between joists