Drywall Clips, backers, Stops – Code Notes
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.
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.