Drywall Grid Systems: Hanging & Framing Flat Ceilings

Work Smarter

Eliminate the labor-intensive cutting, tying, and spacing of track and channel framing. Armstrong's Drywall Grid Systems are engineered with rout locations and cross tees to maintain precise module spacing. Main beams feature 51 rout locations and cross tees are available in 50", 26", and 14" lengths to accommodate Type F fixtures without field modifications or accessories. Pre-notched main beams simplify curved drywall installations.

Our Drywall Systems are manufactured to meet or exceed ASTM standards and code requirements, and are engineered to provide economical alternatives to stud and track construction.

The vertical load carrying capacity for main beam and cross tee members is determined in accordance with ASTM test method E3090. Suspended ceiling systems constructed of screw-attached gypsum board panels may be installed in accordance with ASTM C1858 and are exempt from code prescribed requirements of acoustical or lay-in panel ceilings. This standard practice is limited to framing that supports a single level ceiling and is surrounded by and attached to laterally braced walls or soffits.

Drywall Grid Systems: Code Compliance You Can Trust

Meets:

• ASTM C1858
• ASTM C635
• ASTM C645
• ASTM C754
• ASTM C840
• ASTM E3090
• ICC Evaluation Service Report ESR-1289
• City of LA - RR 25348
• IBC categories D, E, and F single layer drywall ceilings
• Miami-Dade County, Florida impact testing NOA No. 14-1204.05 - 10/07/2019
• Miami-Dade County, Florida wind uplift NOA No. 15-0127.04 - 03/17/2020

Consult local codes for specific requirements.

Performance

• PeakForm^® patented profile increases strength and stability for improved performance during installation.
• SuperLock^™ main beam clip is engineered for a strong secure connection and fast accurate alignment, confirmed with an audible click; easy to remove and relocate.
• ScrewStop^™ reverse hem prevents screw spinoff on 1-1/2" wide face.

Components

Main Beams

Metric

+ Type F fixture compatible

Cross Tees

Metric

NOTE: All items available in High Recycled Content (HRC) as special order.

Molding

NOTE: All items available in High Recycled Content (HRC) as special order.

[Diagram showing SimpleCurve™ Knurled Angle Molding used with 5/8" Gypsum Board]

Corrosion Prevention

Corrosion prevention is an essential factor in the economical utilization of galvanized sheet metal for ceiling suspension systems. Armstrong Ceilings provides G40 for standard construction per ASTM C645. When conditions include exposure to extreme moisture and salt water, G90 is available per ASTM A653.

Material: Commercial-quality cold rolled hot dipped galvanized steel

* 7904PF and 7905PF feature protective film on the acoustical wall angle flange for faster, easier finishing.

Axiom® Trim

Axiom Drywall Transitions

Accessories

Axiom One-Piece Drywall Trim

*For use with 5/8" drywall only

Material: Commercial-quality extruded aluminum alloy 6063

Axiom® Building Perimeter System

Axiom Pocket with Face Plate to Drywall Transition

[Diagram showing Axiom Pocket with Face Plate to Drywall Transition, including components like Optional Stud, 3-Sided Perimeter Pocket, Foam Gasket, HVAC Boot, Splice Plate, Armstrong® Drywall Grid Cross Tee, Window, 2" Closure Clip, Interlocking Spline, Slotted Face Plate, T-Bar Connection Clip, Drywall Taping Flange, Hanger Wire, 5/8" Thick Drywall, Armstrong® Drywall Grid Main Beam]

Rout Locations

Imperial

Metric

Accessories

Drywall Grid Accessories

A variety of drywall grid accessories are available to provide problem-solving solutions that save time, labor, and money. For a complete list of accessories, request submittal BPCS-3082.

Drywall Grid Accessories (continued)

System Framing

Hanging & Framing

The grid system is comprised of main beams and cross tees that are suspended by hanger wires to the structural deck. Sections of main beams lock together end-to-end while cross tees span between the main beams. The ends of the main beams and cross tees rest on the wall channel or angle molding that run around the perimeter of the space.

[Diagram illustrating hanging and framing with main beams, cross tees, hanger wires, wall channel/angle molding, and gypsum wall board. Includes labels for KAM - Knurled Angle Molding, and a note about 107 lbs. Pull Out and 372 lbs. Shear with 25 gauge Pan Head Streaker.]

Squaring Up the System

Once you've hung your first two main beams and border cross tees, install two full cross tees between the main beams in line with the first two border cross tees. To square up the system, simply measure across the diagonals of the opening. The measurements will be the same if the grid is square. If the grid is not square, shorten one of the main beams until the diagonals are equal.

[Diagram illustrating squaring up the system by measuring diagonals A and B.]

Type F Fixtures

Hanging & Framing

Type F fixtures, access panels, and air diffusers require a full 12", 24", or 48" opening dimension. The Armstrong Drywall Grid System main beams and cross tees have additional routs in the web to accommodate this larger opening for type F fixtures. Using our 14", 26", 50", and 72" cross tees, type F fixtures fit perfectly without field cutting or special accessories.

When installing type F fixtures parallel to the main beams, use a 72" and 48" cross tee for easy placement of fixtures without field modifications.

When installing fixtures perpendicular to the main beams, use 72" cross tees for virtually limitless fixture placement.

[Diagram showing main beams at 48" O.C. with placement of XL8947P, HD8906, XL8925, XL8947P, XL8965, XL8925, XL8947P, HD8906.]

[Diagram showing main beams at 72" O.C. with placement of XL8925, XL8965, XL8947P, HD8906, XL8925, XL8965, XL8947P, HD8906.]

Linear Light Trim Kits designed to work with 5/8" drywall

Suspended Drywall Grid Systems

Suspended Drywall Grid System Details

[Diagram showing a layout of a suspended drywall grid system with numbered components.]

1. Butt Joint

5. Type F Fixture

9. Access Door

[Diagram showing a detail of a Butt Joint with Hanger Wire and Gypsum Board.]

[Diagram showing a detail of a Type F Fixture.]

[Diagram showing a detail of an Access Door.]

[Diagram showing details of various components: 2. Expansion Joint*, 3. Wood Trim, 4. Control Joint, 6. Air Bar, 7. High Hat Fixture, 8. Vertical Brace, 10. Securing a Single Cross Tee, 11. Channel and Angle Molding, 12. Angle Clip. Includes labels for MBSC2 Main Beam Spacer Clip, DW90C, DW60C, DW45C, DW30C, XTAC, DDC, Main Beam, Cross Tee, Drywall Screws, Expansion Joint*, Edge Bead, Screw, Wood Trim, Hanger Wire, Angle Molding, Steel Stud, Main Beam, Hanger Wire, Channel Molding, Steel Stud.]

[Diagram showing details of various components: 13. Triple Layer with Security Lath, 14. Double Layer with Security Lath, 15. Double Hung Ceiling, 16. Transition, 17. Axiom® Perimeter Trim, 18. Alternate Finishes, 19. Drywall Vertical, 20. Surface Mount Fixture, 21. Triple Layer with Sound Isolators, 22. HD8906 with IIC Clip. Includes labels for Hanger Wire, Exposed Tee Grid System, Angle Molding, Cross Tee, Acoustical Panel, Gypsum Board, Steel Stud, Drywall Grid System, Drywall Screw, Axiom® - Classic, 5/8" Gypsum Wall Board, Axiom® Drywall Bottom Trim, AXTBC, Axiom - Profiled (Convex), Drywall Screw, DDC, Hanger Wire, Main Beam, Sound Isolator by Others, Plywood or Gypsum Board, Gypsum Board, Surface Mount Light Fixture (Screwed to Main Beam), Hanger Wire, IIC Clip.]

Wire Loading

Hanging & Framing

9 Gauge Wire Breaking Strength and Technical Data

• 9 Gauge Wire
• Diameter: .148"
• Galvanized Steel
• 645 lbs. Maximum Safe Wire Load
• 3 Turns in 3" Per ASTM C636
• 450 lbs. Pullout - Hanger Wire Hole

12 Gauge Wire Breaking Strength and Technical Data

• 12 Gauge Wire
• Diameter: .105"
• Galvanized Steel
• 275 lbs. Maximum Safe Wire Load
• 3 Turns in 3" Per ASTM C636
• 500 lbs. Pullout - Hanger Wire Hole

[Diagram illustrating wire loading with 9 gauge and 12 gauge wire specifications.]

Counter Splayed Wires

Objects in the plenum may obstruct placement of vertical hanger wires and require splayed wires to support the load. When this occurs, a second counter splayed wire must be added. Install counter splayed wires at an angle equal and opposite to the first wire, but not greater than 45° from vertical. The load capacity of the main beam remains unchanged (refer to ASTM C636).

[Diagram illustrating counter splayed wires at 45°, 30°, and 15° angles. Includes a note: "If counter splayed wires are at unequal angles, refer to a local engineer or code official for approval."]

Yoke Wire Hung Ceilings

Hanging & Framing

Another method to install hanger wires around an object in the plenum is to utilize a single or double yoke wire technique. Rule: To form the 45-degree angle, the vertical location of the tension ring is always half the distance of the span at the structure.

Single Yoke

[Diagram illustrating single yoke wire technique with 8' span, 4' vertical drop, and 45° angle. Includes 5/8" Type USS Flat Washer or Equivalent.]

Double Yoke

[Diagram illustrating double yoke wire technique with 12' span, 6' vertical drop, and 45° angle. Includes 5/8" Type USS Flat Washer or Equivalent. Includes notes: "Maintain wire spacing at a maximum 4' O.C."]

Trapeze Supported Loads

Hanging & Framing

Installing a trapeze is a technique to support multiple hanger wires under obstructions, such as trunk lines, cable trays, or other objects in the plenum. In some cases, the trapeze may affect the ceiling height and must be kept small. In other cases, steel studs may be used to span the distance required.

[Diagram illustrating trapeze supported loads with HVAC DUCT, Duct Strap, Cable Trays, Elec. Conduit/Water Lines, Telephone Lines, Trapeze Support Independent of Equipment, Main Beam, Acoustical or Drywall Ceilings, and 4' O.C. spacing.]

Double Hung Ceilings

Hanging & Framing

A suspended ceiling not only carries the load of the applied finish, but can also act as a load carrying structure or membrane that supports another ceiling at a lower level. The DDC clip is used at hanger wire locations to allow for connecting the second and even third ceiling. This method of hanging and framing is used in multi-layer ceilings with long vertical drops – eliminating the use of long stud drops.

[Diagram illustrating double hung ceilings with DDC clips, Main Beam, Hanger Wires, Drywall Grid System, Wall Angle, Partition Wall, Sound Isolator, Double Layer Gypsum Wall Board, Steel Stud, DW45C.]

Gusset Hung Ceiling

[Diagram illustrating gusset hung ceiling with 2" x 6" Wood Block, Wire Clip or Eye Screw into Wood Block, Plumbing TW Wire Cable, Loading at Top of Wall in Wood Block, Electricity, Security, etc., #9 Wire 500 lbs., DWC Clip.]

Triple Hung Ceilings

Hanging & Framing

[Diagram illustrating triple hung ceilings with Drywall Grid System, Insulation, DDC Clip, Pipe Chase, Duct, Drywall Grid System, Drywall Grid System, DW45C, Channel Molding, Drywall Main Beam, Drywall Main Beam, DDC, Channel Molding, DW90C, Roof Deck, Bar Joist, Gypsum Board, Steel Stud. Labeled as 1st, 2nd, 3rd levels.]

Exterior Wind Load Data

Exterior Wind Load Ceiling Design for North America

[Table detailing Exterior Wind Load Ceiling Design for North America, including Plenum Height, Velocity Pressure, Design Pressure, Post Size, Post Gauge, Sheathing Membrane Substrate, Compression Post, Main Beam, Cross Tee, Hanger Wire Spacing, Tee Length, and Compression Post Load.]

NOTE: For building heights over 20 feet, refer to ASCE 7-10 Chapter 6 Wind Loads.

UL® Fire Resistive

Hanging & Framing

[Table detailing UL® Fire Resistive Floor/Ceiling Drywall Assemblies and Wood Deck/Ceiling Drywall Assemblies, including Deck Construction Type, UL® Design Number, Concrete Thickness, # Drywall Layers, Minimum Drywall Thickness, Maximum Fixture Penetration, Maximum Duct Penetration, and Drywall Grid System.]

[Table detailing UL® Fire Resistive Roof/Ceiling Drywall Assemblies, including Deck Construction Type, UL Design Number, Concrete Thickness, # Drywall Layers, Minimum Drywall Thickness, Maximum Fixture Penetration, Maximum Duct Penetration, and Drywall Grid System.]

Armstrong® Drywall "Design To Fit" Items XL7936G90 and XL8965 cannot be used as part of a UL Fire Resistive Design.

DFR 8000 - UL Designation, Fire Guard™ Drywall Grid System.

For fire-rated assemblies, use Type C gypsum board as noted in the UL fire-rated assembly designs.

Fire Rated Expansion Joint

[Diagram showing a fire expansion notch and a collapsed fire expansion notch.]

Load Data

Main Beam - Technical Load Test Data

[Table showing Main Beam Technical Load Test Data for Imperial and Metric units, including Simple Span loads.]

Cross Tees - Technical Load Test Data

[Table showing Cross Tees Technical Load Test Data for Imperial and Metric units, including Simple Span loads.]

NOTE: Allowable loads tested per ASTM C635 for deflection limited to L/360 and complies with ASTM C645 for deflection limited to L/240. See standards for additional information.

Membrane Load Values

[Table showing Membrane Load Values for Imperial and Metric units, including Maximum Load in lbs./ft.2 at Hanger Wire/Cross Tee Spacing and Maximum Load in kg/lm² at Hanger Wire/Cross Tee Spacing.]

Basic Products

Basic Products Used on Suspension Systems

[Table listing basic products used on suspension systems, including Material, Weight Lbs/SF, Maximum Main Beam Spacing, Maximum Cross Tee Spacing, Maximum Wire Spacing, and Load on Wire.]

NOTES: All framing on the exterior should be 16" O.C. or less.

Some manufacturers make 1/2" gypsum board with special core to span 24" framing on interior ceiling installations (available on request).

All steel product on exterior made from G90 galvanized finish.

Data based on manufacturer's published data.

Use lower RPM (1,000-2,500) screw gun to install cement board screws with intermittent pressure.

Control Joints

Please refer to ASTM C840, Section 20.3.3 to 20.4 for Control Joint Requirements.

[Diagram illustrating a control joint.]

Expansion Joints

Ceiling expansion joints are installed to separate the metal suspension system when expansion joints occur in buildings or when metal changes direction. Expansion joints are required to separate a system in T-, H-, I-, and U-, or circle-shaped buildings to eliminate cracking from expansion.

[Diagram illustrating an expansion joint.]

Sound Control

Hanging & Framing

The IBC uses two sound classes to measure sound isolation performance in building construction: Sound Transmission Class (STC) – sound transmitted through the air such as voices and music. Impact Insulation Class (IIC) – sound transmitted through the building structure such as foot traffic and objects dropped on the floor. A rating of 50 or above for both STC and IIC sound tests will satisfy the IBC's minimum requirements.

Understanding Sound Control Ratings

Satisfy IBC requirements with a rating of 50 or above for STC and IIC sound tests - without two layers of drywall using Armstrong® Drywall Grid.

Traditional Assembly - Field Tested Data

Armstrong® Standard Drywall Grid Assembly - Field Tested Data

Armstrong® IIC Drywall Grid Assembly - Field Tested Data

[Diagram showing Armstrong® IIC Drywall Grid Assembly with HD8906IIC 12' Main Beam, XL8945 4' DGS Tee (Wires 4' O.C.), 3-1/2" Batt Insulation, Ceiling - One Layer 5/8" Gypsum, and IIC Clip.]

Estimating

Estimating Material

[Table showing Area of ceiling completed by one carton (SF) for various grid components and spacing.]

Example calculation based on 5,100 SF ceiling:

Main beam at 48" O.C.: 5,100 SF x .25 = 1,275 LF. 1,275 LF ÷ 144 LF/Ctn = 9 cartons needed

Cross tee at 16" O.C.: 5,100 SF x .76 = 3,876 LF. 3,876 LF ÷ 144 LF/Ctn = 27 cartons needed

[Table showing Estimating Lineal Feet of Grid Based on Square Footage of Ceiling for various O.C. Spacing of Component.]