The metal furring strips need to be nailed to something solid in order to hold the ceiling and prevent it from sagging. The ceiling joists, which are the wooden framing members that support the existing ceiling, will work when the furring strips are nailed perpendicularly across them.
Drive a nail everywhere a furring strip crosses a joist. If the ceiling joists are exposed, it is a simple procedure. If there is an existing ceiling, a little more work is required.
Locate the joists and mark them on the existing ceiling so that you will be able to nail the furring strips to them. If there is an attic above, determine the direction of the ceiling joists.
They usually run across the short dimension of the room. Tap the ceiling with a hammer to determine where the sound is most solid. Drill a hole or drive in a nail to be sure you have located a joist
You can also use a stud finder. Newer stud finders measure the density behind the finish materials to locate studs and joists. Locate either end of each joist where they rest on the wall and snap a chalkline down the center of each joist.
Once you have located the first joist, the others should be located either 12, 16 or 24-inches from each other. Still test with a nail or a drill. In many older homes, and even some newer ones, these distances are not always dependably the same.
Installing the First Row of Metal Furring Strips
After marking the location of the joists on your existing ceiling, you are ready to install metal furring strips, which are also called tracks. These strips are sold in 4-inch sections.
The strips must be well secured to the ceiling joists, level, and parallel. In many old houses, the ceilings are often waved and buckled. That can cause problems, since the tile ceiling will be equally wavy if the problem is not corrected.
Study the ceiling before applying the strips. Place a level or a straight board against the ceiling to check for buckles and other irregularities. Note any particularly bad problems. As you install the strips, add wooden shims between the ceiling and the furring strip to fill any dips in the ceiling.
Smaller dips of .25-inches or so, will not need shims. In this case, the strips can span on their own. Just be sure that the strips are within .25-inches of being even. Begin with your first row by the wall. Do not nail it right next to the wall; it should be 1-inch away from the wall. Drive on of the nails from the kit at each joist.
Tug it to be sure that it is well secured. Use 2 nails for every 4-inches of track. You do not want it to start sagging after the tiles installed. Continue placing the 4-inch strips 1-inch from the wall. It is not essential that the ends of the strips butt right up against each other. There can be as much as a .25-inch gap between each strip.
The joints do not need to meet over a joist. Just be sure that the tracks are on line, since you may need to attach a clip over the junction of 2 tracks.
When you reach the other end of the wall, you may need to cut a section of the 4-inch strips to fit the last section. That can be done with a fine-tooth hacksaw.