Masonry Magazine October 1992 Page. 18
horizontal and vertical cracking and rusting of the joint reinforcement in cracked horizontal bed joints.
Whatever the reason for distress, the cause of the distress should be identified, remedied and then restored so inner and exterior wythes work together. The original masonry tie system must be complemented to reduce further movement and to insure safety to others. Knowledge of the through-wall details, materials and the present condition of the masonry tie system will assist in the proper restoration of these masonry segments. Frequently, additional anchorage for the two wythes is necessary.
Number of anchors available
Repair ties provide a solution to defective walls with corroded ties or those walls requiring ties for other reasons. There are a number of repair or stabilization anchors available.
Mechanically expanded anchors have been used successfully for some years. They consist of brass expanding shells on each end of a threaded rod. Wall details are very necessary to choose the correct length of the tie. The access hole required for installation is usually between 1½" and 4".
The inner expansion assembly is fitted onto a threaded shaft and into the locking key assembly then inserted through the exterior hole into the inner wall and torqued to between 50 and 100 inch pounds. Care must be taken not to crush or crack the interior wall. The key assembly is removed and the outer shield installed, then tightened with a socket or screw driver to 50 to 100 inch pounds. The exterior hole is then filled.
Adhesive anchors are also a method of repair and stabilization of brick veneer walls. Again, selection of the proper tie is necessary. A hole is drilled through the veneer and into the backup to the proper depth and size. A resin adhesive is mixed, then inserted into a screen tube installed into the hole then the rod or bolt is pushed into the adhesive filled hole. Rotation of the rod while inserting into the hole will assure bond between the threads and adhesive.
A unique development of a repair anchor has recently been introduced to America from England. This helical tie, developed specifically for masonry repair, is simple and very effective. The tie consists of a stainless steel helical spike that is hammered into the inner wall component after predrilling the exterior wythe and pilot hole drilling the inner wythe. The tie is then secured in the outer wythe with epoxy resin adhesive. Being made of stainless steel, corrosion is at a minimum and flexibility is attained. The system can also be tested for pull out from the backup. This system is simple, inexpensive and proven in Europe for over six years.
New screw tie developed
Because of the problem of deteriorating brick veneer walls over metal stud backup, a new screw in tie has been developed and will be available soon. With a distressed wall such as bulging, cracking or distorting of the brick veneer a thorough examination must be done to identify the problem. If the problem is failure of wall ties or insufficient ties this new tie is ideal. It consists of a self drilling, self tapping screw connected to a specially design threaded rod. After locating the metal stud, a clearance hole is drilled through the brick veneer, the assembly inserted into the hole and power drilled home. The tie torques off at a predetermined location and the hole is filled with resin adhesive. The system is simple and inexpensive.
Most masonry walls showing dis-
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SCAFFOLD COMPONENTS
FRAMES
ACCESSORIES
TOP QUALITY EQUIPMENT FOR
THE CONSTRUCTION INDUSTRY
MASON-JAX AUTOMATED
MASONRY SYSTEM
MASONRY AUTOMATION
REACHES A NEW
OPERATING AND
QUALITY
STANDARD
A
Billax
A LEADER IN THE SCAFFOLD INDUSTRY
595 E. LUGBILL RD. ARCHBOLD, OH 43502
PH. (419) 445-8915 or (800) 537-0540
18 MASONRY-SEPTEMBER/OCTOBER, 1992
Illustrated without
winching mechanism.
All photos and drawings are for illustration only.
AN AMERICAN COMPANY
BUILDING AMERICA
SINCE 1947