Suspended Ceilings 3 - Planning Your Ceiling
Careful planning is essential for a successful ceiling installation. If you shortchange this step, you will slap your forehead in frustration more than once. Plan well, and the rest of the job will go easily. Outlined here are the important issues in planning the ceiling installation.
Step 1 - Estimate the Materials
Wall moldings are available in 10-foot lengths. Measure the room's perimeter and divide by 10 to find the number of wall molding pieces you will need.
Main runners are available in 12-foot lengths. Tabs at each end of the main runners make it possible to join main runners for lengths longer than 12-feet. However, no more than two sections can be cut from each 12-foot length of main runner.
Cross tees come in both 2-foot and 4-foot lengths with connecting tabs at each end. These connecting tabs are inserted into indentations that occur periodically in the runners, and cross tees.
Hanger wire of 12-16 gauges is needed to hang the runners every 4-feet. The wire at this point is 6-inches longer than the distance between the eyehook and the new ceiling.
Wire fasteners or eyehooks are necessary at each support point to attach the hanger wire to the ceiling joist. Ceiling panels will be indicated by the layout. Allow enough to cut for border tiles. Also, purchase all needed lighting fixtures.
Step 2 - Locate the Ceiling Joists
First locate where your ceiling joists so that you will know which direction your runners are to run. If the ceiling joists are exposed, there is no problem. If they are hidden within the old ceiling, you will need to use a hammer or a stud finder to locate them. They usually run across the short dimension of the room. Use a chalkline to snap a line down the center of each joist on the old ceiling.
Step 3 – Determine the Size of the Border Tiles
Border tiles are the tiles that run next to all the walls. Since rooms are rarely on exact 2 or 4-foot intervals, these tiles are often cut to fit. For appearance's sake, you want the border tiles on opposing sides of the room to be equal. All border tiles should be more than half a tile. You want to place both cross tees and runners in such a way that this is successfully accomplished.
Determine the size of the border tiles so they are more than half a tile and equal. To do this, convert the room's short wall measurements into inches. If you are using 2x4-foot panels, divide this measurement by 48 (inches) if the panel length is to run parallel to the short wall. If you are using 2x2-foot panels, or if the panel length will run parallel to the long wall, divide by 2-inches.
Take the remainder of this division and add 48-inches if the panel length will run parallel to the short wall and if you are using 2x4-foot panels. Add 24-inches if you are using 2x2-foot panels, or if the panel length will run parallel to the long wall. Half of this final figure equals the border dimensions at each side of the room.
Here's an example. For a room that is 10-feet 2-inches wide with the panels' length running parallel to the short wall and using 2x4-foot panels. Convert the width to 122-inches. Divide 122-inches by 48-inches and determine two full panel lengths with a remainder of 26-inches. Add 48-inches to 26-inches to equate 74-inches. Then divide by 2 and get 37-inches". Thus, the border panels at each side will be 37-inches. There will be one full-size tile and two 37-inch border tiles (37 + 48 + 37=122). This dimension of 37-inches also equals the distance of the first main runner from the sidewall.
Repeat these calculations using the length of the room to find the end border panel size. Using graph paper, begin to make a diagram of where all your runners and cross tees will go. First you must determine the size of all border panels.
Step 4 - Laying Out the Grid
Now that you have determined the size of the border tiles, you can draw the full grid on the graph paper. Indicate the main runners on your graph paper by drawing the first and last runners at a border tile distance from the sidewalls and perpendicular to the ceiling joists.
Add the main runners at intervals of 4-feet. Using a different color pencil, mark the cross tees on the layout sheet. Start at the border tile distance from the end walls (14-inches in our example). Add the cross tees every 2-feet. The cross tees will intersect with the main runners. If you are using 2x2-foot panels, additional cross tees will be needed to lock into the perpendicular cross tees halfway between the main runners.
Step 5 - Account for Columns and Posts
If you have any columns or posts in the room that support the floor system of the floor above, these will have to be accounted for. This situation is common in basements. The grid must be planned so that no runners or cross tees run into a column or post. If this is the case, you will need to make a slight adjustment so that the column falls in the open area of the grid. Doing so may require unequal border tiles. The location of light fixtures will not require any changes to your grid, but they should be marked on the grid. Remember to do all of your rough wiring before installing the grid.