By Timothy Chapel
Sometimes acoustical ceilings aren’t practical for a particular project. They may not fit within the design requirements of certain designers and architects. Additionally, repairing the existing drywall or plaster ceilings on a project may not be possible either because of duct work, data lines, gas lines or other accessory units that may need to be installed to accommodate the lifestyle of people today.
In some cases the only option in order to retain the existing look of the hard ceiling would be to install a suspended drywall ceiling system. This allows all accessories to be installed into the cavity above the grid systems.
Drywall ceiling systems can be installed almost anywhere you would install a suspended acoustical ceiling. Here are some installation tips on installing them.
Step 1 Overview of a drywall drop ceiling grid system
Drywall suspended grid systems consist of a heavy duty main runner, 4’ tees and an L-shaped wall angle. The configurations of the grid pattern typically are 24” x 48” or 16” x 48”.
Drywall grid main runners are slotted every 8” instead of 6” as with a standard drop ceiling grid main runner. This allows you to achieve the 16” or 24” spacing required for meeting the drywall code. Most installations today are at the 24” spacing however depending on drywall thickness and whether or not the drywall is fire rated, this spacing can change.
Drywall suspended grid systems are very heavy duty and are more difficult to cut than standard drop ceiling grid systems. The L-shaped wall angle is usually 20 gage or 25 gage material. Although drywall grid systems are more difficult to cut they install very quickly because the grid system is not exposed, therefore you don’t have to be as precise with how the system is assemble.
Step 2 Installing the wires and fasteners for a drywall grid system
The ceiling support wires are installed just like any normal acoustical ceiling. The support wires are spaced 4 lineal feet apart down the length of the main and 4’ apart between each main as well. It is very important that the wires are installed into a solid structure because drywall grid systems need to be able to support a large load capacity.
The main runners for a drywall grid system are more heavy duty than standard main runners for acoustical systems and can handle additional loads.
Drywall grid mains are rated at 19 lbs per lineal ft while standard drop ceiling grid is rated at 14 lbs. Both, however, require wire spacing of 4 lineal feet.
Step 3 Installing the perimeter wall angle for a drywall grid system
The wall angle for a drywall grid system is a 1 ½” x 1 ½” L-shaped piece of steel angle. They’re purchased in either 10 or 12-foot lengths and are typically 20 or 25 gage material.
The wall angle is installed just like any other acoustical ceiling however, you need to take into account the thickness of the drywall when verifying the correct ceiling height. Example: If 8’ ceiling height is desired, set wall angle at 8’0 5/8”. (5/8” being the thickness of the drywall.)
First…Secure the angle to the wall with a couple of fasteners and hang your laser. If the drywall is already installed on the walls, we normally fasten the wall angle with a staple gun every 4”-6” apart and install the staples vertically for better support. If there is no drywall you can fasten the angle directly to the steel stud itself. Use the fastener that corresponds with your application.
One thing to keep in mind is that the wall angle doesn’t have to look pretty. For instance…on an outside corner, you can simply cut the angle flush with the corner. There’s no need to extend, overlap, or miter any outside corners.
Also…for seams, you can butt the two pieces together or you can overlap them…it’s your choice.
Step 4 Figuring the layout for the drywall suspended grid
The size of the room that we are looking at with our project is approximately 700 sq ft.
Figuring the layout for drywall grid system is not as critical as with an acoustical systems because the drywall will cover the framing members. However, you must consider the location of light fixtures and other accessories when figuring the layout.
In most cases we always begin the grid starting at 4 feet off the longest wall.
The reason for this is the ease of installation for the grid installer and secondly the drywall installer won’t have to cut his first sheet for his installation either.
If the layout allows, start the grid at 4’ off the wall.
When planning your layout, it’s important to look carefully at all aspects of the room including hallways. On residential or commercial projects you’ll want to make sure that there isn’t a cross tee running down the center of the hallway.
Try to have a 2’ space somewhat centered down the hall as this will allow for the possibility of light fixtures.
Step 5 Installing the main runners and 4’ cross tees for the drywall grid system
Once you’ve planned the layout you’re ready to install the grid. Hang the laser on the wall and adjust the beam so that it is running slightly below the wall angle.
Main runners for drywall grid systems are 12’ and they have a 1 ½” wide face as compared to the 1” or ½” wide face for acoustical ceilings.
Drywall mains have 3 consecutive slots. They are designed so that the tees can be installed every 16 or 24 inches.
Because of the number of slots on the main and the fact that layouts typically are not critical there is no need to measure and cut back the main like you would for an acoustical installation.
Simply cut the tab off on the end of the main and begin with that.
If you have a layout that requires precision, then measure back from the slot and cut the main at the proper dimension.
Install the main and temporarily hang the wires to secure it. For an acoustical ceiling you would run the first two mains…run a string line and then cut in the wall tees, but in a drywall grid system, you can install the wall tees right away.
Begin installing the 4’ tees in the proper slots after you’ve hung each main. There should only be two of the same slots in between the tee’s for 24” spacing.
Install the next main and repeat the procedure, using a clamp every so often to temporarily secure the grid. Once at the end, measure from the wall to the end of the main. Cut and install the main.
Install the remainder of the 4’ tees and clamp the end of the main.
Because the wall tees are installed you can level the main and finish the wires right away.
Use the laser beam as a height reference and tie up the wires to keep them out of the way of the string line that you are about to run.
Be sure that you pull down on all wires to remove the slack, because drywall ceilings are heavier than standard ceilings and the sag potential is greater.
Step 6 Securing the main runners and 4’ cross tees to the wall angle
You will need to secure the main runners and cross tees to the wall angle by installing a ½” or 9/16” self-tapping pan head screw. There are two ways that you can do this.
- Punch the main with your Strictly Ceilings punch pliers and then install the screw into the hole.
- Or, simply allow the self-tapper to bore its way through the metal without pre-punching it.
Once both ends of the main is secured, you will need to run a string line to straighten the main.
Install the string on the outside of the main and run it down the entire length. Clamp the string on the same side of the main at each end.
Secure the cross tees at the wall by squaring one tee and then measuring off that tee…2’, 4’ and 6’ from the tee we squared. Here’s the proper installation sequence:
- Adjust the main in or out so that the main is on the line and straight.
- Using a speed square, adjust the cross tee so that it’s square with the main runner.
- Place a mark on the wall at that location and temporarily clamp the main.
- Measure 2 feet from the squared tee and slide the next tee over until it’s at that location.
- Repeat the same thing at the 4 foot and 6 foot locations.
- Using a cordless screw gun, fasten all six tees to the angle with the self-tapping screws.
- Move down the main and repeat the procedure…squaring, measuring, and securing the tees.
For the next main runner being installed 4’ over from the first main, simply repeat this procedure with a couple of exceptions.
- Begin by installing a 4’ tee and just let it hang.
- Using your tape measure…place the tape in the molding and while aligning the 4’ tee with the tee on the 1st main, determine what the measurement is from the wall to center of the tee.
- Scribe a line on the main from the slot to give you that dimension.
- Cut off the main at that location and install the main.
- Install the loose tee at the proper location and one more tee to straighten the main.
- Clamp the main and check for square. Square for drywall grid systems should be 51 ½” for the 2×4 method.
- Adjust the main in or out to achieve square and cross check both ways. Once square…punch a hole and secure the main with a screw.
- Install any additional 4’ cross tees, tie up any wires that need to be secured and then install the next main.
- Cut the cross tees into the opposite wall and fasten with a screw.
Take a look at the full video to get step-by-step visual instructions on exactly how to install a drywall suspended grid system.
In the video we cover the following applications.
- Overview and applications of a drywall grid system
- Wire and fastener installation
- Figuring layouts for a drywall grid system
- How-to install a drywall grid system in a 700, 400 & 100 sq ft room
- How-to build a drywall soffit system using the grid material
- Many tips and tricks for installing drywall grid systems.
Good luck installing suspended ceilings! –Tim