Metal or plastic drywall clips can be used to replace a third stud at a corner, at a partition intersection backing stud, or in the ceiling to replace wood or metal blocking. The reduced attachment (wood to drywall) resulting from the use of dry wall clips allows small movements without drywall cracking and nail pops. Small movements are normal as wood responds to changes in temperature and moisture content over time.
Eliminating unnecessary wood framing within walls can increase the thermal efficiency of the wall system. Less framing allows more insulation to be installed and also eliminates hot and cold spots (from thermal bridging through the frame) within the wall system.
Two-stud corners and drywall clips are often used in combination with airtight drywall, where the drywall and well sealed gypboard seams provide an effective interior air barrier.
Exterior walls of wood-frame construction shall be designed and constructed in accordance with the provisions of this chapter and Figures R602.3(1) and R602.3(2) or in accordance with AF and PA's NDS. Components of exterior walls shall be fastened in accordance with Table R602.3(1) through R602.3(4). [Excerpt]
Note: A third stud and/or partition intersection backing studs shall be permitted to be omitted through the use of wood back-up cleats, metal drywall clips, or other approved devices that will serve as adequate backing for the facing materials.
Section R602 of the International Residential Code (IRC) covers wood wall framing requirements. Specific provisions are provided for single top plates with rafters or joints centered over studs (R602.3.2), studs spaced 24” oc (R602.2.4), and two stud corners (Figure R602.3(2)). Special designs may be required in seismic or high-wind zones.
PATH Field Evaluation for Habitat for Humanity in Anne Arundel County, Maryland evaluated use of in-line framing; lining up joists and roof rafters with wall studs eliminated need for a double top plate; saved time and money during construction without sacrificing structural strength
Warranties are not affected by OVE advanced framing techniques.
- Framing crew will need to review and follow framing plans specifically as designed in order to implement techniques
- Use 2 x 4 at 24” oc when framing single-story construction, and 2 x 6 at 24”oc for 2-story construction in most regions
- Design 24” oc framing to resist hurricane, high wind, or earthquake forces; some jurisdictions may not allow 24” oc framing
The links on this page illustrate the wide use of drywall backers or clips to create strategies to reduce drywall cracking, truss uplift, eliminate redundant framing, save on materials, seal wiring and plumbing areas, and honor sustainable building.
Advanced framing techniques and the use of drywall backers are recommended by the US Department of Energy, Department of Defense, NASA, HUD, and leading builders nation wide. If you experience a local building inspector without this knowledge, please refer them to these resources.
Codes and Testing
Uniform Building Codes
Regarding the generic term ‘drywall clip and/or backer’, it has
been verified by the National Code Organization that the Uniform
Building Codes do not address drywall clips or backers in the
written language of the code books. They defer to the Gypsum
Associations’ standards as the controlling force on all procedures
regarding wallboard installation. The Gypsum Association allows
clips/backers if tested and approved according to ASTM standards
(American Society for Testing and Materials).
Reference to gypsum wallboard in the building code books is derived
from Gypsum Association specifications found in GA-216. In the CABO
code book, this is found in Chapter 5, Section R-502.5 and reads as
follows.
R502.5 Gypsum wallboard: All gypsum wallboard shall conform to
ASTM C36, C474,
and C475 listed in Section S-26.502 and shall be installed in
accordance with ASTM C557 and GA-216 listed in Section S-26.502 and
the provisions of this section. Gypsum wallboard shall not be
installed until weather protection is provided.
All Edges and ends of gypsum wallboard shall occur on the framing
members, except those edges and ends which are perpendicular to the
framing members.
Support spacing and the size and spacing of backers shall comply
with Table No. R-502.5
Specifications in GA-216 refer to ‘Application and Finishing of
Gypsum Board’. Reference to ASTM C557 relates to “Standard
Specifications for Adhesives for Fastening Gypsum Wallboard to Wood
Framing” and does not apply to clips or backers.
The second paragraph concerning “All edges and ends …” describes
that gypsum wallboard does not have to continuously fall on framing
members, i.e. between studs. Edges and ends perpendicular to framing
members must occur on increments determined by the Maximum Spacing
of Framing Members’ column in CABO Table No. R-502.5 (also GA
specifications).
In addition to installation of structural framing members, ‘Maximum
Spacing of Framing Member’ specifications also determine the spacing
of 2x4 and 2x6 ladder panel blocking in lieu of continuous wood
backing to support interior corners. The horizontal ladder panels,
in similar fashion to vertical studs, are perpendicular to the edge
and/or ends of the wallboard. Clips or backers in place of wood
provide the same function and should likewise be installed according
to these procedures. (see table on the following page)
CABO Table No. R-502.5
The ‘Maximum Spacing of Framing Members’ column allows 16” to 24”
spacing with or without adhesive application. For best performance
and to simplify installation procedures, The Millennium Group
recommends 16” spacing when installing THE NAILER in lieu of wood
backing.
Since ‘Maximum Spacing of Framing Members’ predominates for
installation of blocking/clips, ‘Maximum Spacing of backers’
specifications (screws or nails) do not apply to the edges or ends
of the wallboard perpendicular to these components. Regardless of
whether wallboard is secured with nails or screws, 2x4
blocking/clip/backers may be installed according to the 16” or 24”
increments.
In reference to fastening wallboard at interior corners, the Gypsum
Association recommends to float the sheet of wallboard supported be
the backing/clips/backers; do not fasten this sheet at all. (see
following page)
Gypsum Association Specifications
The specifications in GA-216 that describe floating interior angles
are addressed in Section 5.3 ‘Nailing Schedule for Single Ply Gypsum
Board’ (Figure 2), and Section 5.5 ‘Floating Interior Angles’
(Figures 4, 5 & 6)
The above illustration related to Section 5.3 demonstrates nailing
requirements and indicated the omission of nails (floating) at
vertical and horizontal interior corners.
GA Section 5.5 Floating Interior Angles
5.5 Floating Interior Angles
To minimize the effects of truss uplift and the possibility of
backer popping in areas adjacent to wall and ceiling the floating
angle method of application should be used for either single or
double layer application of gypsum board to wood framing. This
method is applicable where single nailing, double nailing, or screw
attachment is used. Gypsum board should be applied to ceiling first.
(See Figures 4, 5 and 6) Floating interior angles should not be used
where fire ratings are required.
5.5.1 First attachment into each ceiling framing member framed
either perpendicular or parallel to wall intersection should be
located 7 in. out from intersection for single nailing, and 12 in.
for double nailing or screw application.
5.5.2 Gypsum board on sidewalls should be applied to provide a firm
support for floated edges of ceiling gypsum board. Top attachment
into each stud should be located 8 in. down from the ceiling
intersection for single nailing, and 12 in. for double nailing or
screw application. (See Figures 4 and 5) At sidewall vertical
angles, (Figure 6), overlapping board into firm contact with face of
framing member behind it. NOTE: Special clips designed to provide
support at wall corners and wall-ceiling intersections in lieu of
back-up stud or blocking may be used where approved.
A brief description of design and application features are as follows:
* THE NAILER is made of 20 gauge galvanized steel or from #2 High Density Polyethylene (HDPE), 100% recycled plastic. Due to the recycled nature of the raw n\material it is produced in a wide array of different colors. To maintain the 100% recycled claim, The Millennium Group has elected not to introduce an artificial additive for color uniformity.
* The recycled plastic NAILER is an injection molded product manufactured in Madison, WI. THE NAILER is a U.S. Trademarked and Patented product (U.S. Pat. No. 5,581,964).
* THE NAILER is a ‘T’ shaped plastic device designed for drywall
fastening (or backing) purposes in lieu of non-structural,
non-load bearing wood backing.
* It is installed at 16” increments with two (1/2”) staples, one
nail (1” min.), or one screw (1” min.) placed through the
downstem. THE NAILER can be used in both wood and steel framed
construction.
* THE NAILER is 1 ½” in width and can be used to secure two
sheets of drywall where they meet at a seam in similar fashion
to the joining of two sheets on a 1 1 /2” stud or ceiling joist.
* The planar member used for fastening/support of the drywall is
1 3/8” in length and has an anti-skating grid surface to prevent
screws from slipping across the surface
* A 5/8” backtab coupled with a ¼” ridge running the entire
length of the backslide provides extra support in addition to
securing the downstem.
The NAILER (product testing and Approval)
Testing
was performed in 1994 by PFS, and independent 3rd party testing
laboratory that specializes in the testing and approval of
construction materials. PFS is headquartered in Madison, WI (608)
221-3361. Test results indicate THE NAILER meets or exceed the four
levels of criteria that apply to the product category and to the
specific makeup of THE NAILER itself.
Test procedures and results are as follows:
RACKING RESISTANCE – Tests were conducted in accordance with ASTM
E 72-80, Section 14. Ten wall panel frames were tested. Drywall was
attached with screws to the wall panel studs and to THE NAILER in
lieu of wood backing at an interior corner example of a bisecting
wall. THE NAILER was installed to the wood studs with ½” staples.
Increased levels of load pressure was applied to each panel until a
deflection of 1/8 inch occurred.
Results indicate that THE NAILER can be used as a drywall support
clip for ceiling and corner fastening of drywall and drywall-to-woof
construction. As the panels shifted under the load, gypsum broke
away from screw backers on stud members while staples fastening
THE NAILER to the stud only slightly pulled away fro the stud. THE
NAILER actually performed better that the studs with regard to the
holding power of the screws.
IMPACT LOAD TESTS – Tests were conducted in accordance with ASTM E
695-79, Section 8.4. A weight bag was set up to impact the wall
panels at varying increments. Deflection and set measurements were
recorded at each 6 inch progressive impact to test the strength of
THE NAILER’s holding power in the corners.
Results indicate that THE NAILER can be used as a drywall support
clip for ceiling and corner fastening of drywall and drywall-to-wood
construction. Tests showed that the drywall fractured between THE
NAILER and the next closest stud without and adverse effects upon
THE NAILER.
ACCELERATED AGING OF PLASTICS – Tests were conducted in accordance
with ASTM D 756-78, “Determination of Weight and Shape Changes of
Plastics under Accelerated Service Conditions.” A minimum if five
NAILERS were tested per Aging Cycle Procedure. All seven of the
Standard ASTM cycling procedures were conducted. After each stage of
the cycling procedure, the NAILERS were weighed, measured and
visually examined. (Cont’d on next page)
Results indicate that THE NAILER can be used as a drywall support
clip for ceiling and corner fastening of drywall and drywall-to-wood
construction. The data showed that there was no change in appearance
of any tested NAILER. Only a slight percent of change was measured
in weight or dimension.
R & D SPLITTING TESTS – Tests were conducted to determine THE
NAILER’s characteristics through practical application at extreme
temperatures. Five NAILERS were exposed to – 20 degrees F, and five
NAILERS were exposed to 110 degrees F. After ten days of exposure,
the NAILERS were stapled to studs (also exposed to the extreme
temperatures), and a drywall screw was screwed through each NAILER
where the gypsum would be fastened.
Results indicate THE NAILER can be used as a drywall support clip
for ceiling and corner fastening of drywall and drywall-to-wood
construction. After a thorough visual examination, there is no
visible adverse change in structure to the NAILER at either high or
low temperature exposures.
To obtain a copy of the specifications in GA-216 contact The Gypsum
Association at (202) 289-5440
, Inc. Falls Church, Virginia. 2000 International Residential Code; and Copyright, 2003,