Masonry Magazine September 2004 Page. 32
Wall Bracing
Masonry construction is drastically different from other forms of construction.
during construction. The primary goal of this guide is to provide life safety for masons and other workers on a construction site during the time when a masonry wall is being constructed.
Research and Updates
MASONRY CONSTRUCTION is drastically different from other forms of construction. For example, when precast and tilt-up walls are erected, they have the majority of their final design strength and can resist most wind loads. However, masonry walls are subjected to wind loads before the final design strength is achieved. This means that masonry walls can fall down under less severe wind conditions. This being the case, the Council needed to determine what was the wind speed at which the mason's safety was being compromised.
After testing was completed, data indicated that masonry walls started to severely alter their shapes when wind speeds reached 60 miles per hour (mph). Testing also showed that wind speeds that high did not allow the mason to accurately place the masonry unit, especially when on scaffolding. Therefore, it was agreed upon by the Council that the wall bracing in the Standard Practice be designed to resist a wind speed of 40 mph and evacuated at 35 mph. Once evacuated, the limited access zone then
BEYOND 2X4S
Wall bracing isn't really considered a favorite pastime by mason contractors and their crews, but it doesn't have to be a painful process. Several products recently introduced to the masonry market are here to save the day and make wall bracing a pain of the past. Three such products include: Hog Leg, introduced by EZ Grout Corporation of Waterford, Ohio: Dur-O-Wal's Brace Rite System of Aurora, III.; and Adjust-It from Jakerstin Bracing, Inc., of North Monmouth, Maine.
"The contractors we talked with agreed that existing systems were heavy and cumbersome to install on masonry walls," says Damian Lang, Owner of EZ Grout. "They required a minimum of two or three people to install them, and could not be installed through head joints as the wall was being built. Because bracing was such a difficult task, many looked for ways to 'shortcut instead of bracing properly. Our system is designed to eliminate that headache."
Headaches are gone for the mason contractor, while backaches are disappearing for the crews. All of the new bracing systems offer engineered and tested products, fast and easy installation, and the requirement of only having to brace one side although both sides can be braced as well. Add the bonus of only having to use one or two crewmembers, and you've got yourself a winning combination. Many of the companies also offer engineering assistance so that you can brace the most common to most unusual wall configuration. "Upon receiving a worksheet that we have on our web site filled out with the specifics of your project wall, you will receive a site-specific bracing design stamped by our structural engineer," says Dawn Hodsdon, Co-owner of Jakerstin Bracing, "Or, if you just need the appropriate weight calculations for above-ground footers if you're going to be bracing on one side of the wall, we can do that too... or both."
"The fact that mason contractors only have to brace from one side of the wall allows them to continue work much more easily than having to brace both sides, like with wood plank or cable bracing," says Vinny Mendes, Regional Sales Manager for Dur-O-Wal. "Also, unlike the standard plank bracing, our system is engineered and has been known to reduce insurance costs."