Masonry Magazine August 1978 Page. 15
CAVITY SPACE MAY CONTAIN BOARD OR FILL TYPE INSULATION
3/16" (4.8 mm) DIAMETER ROUND TIES OR OF EQUIVALENT STIFFNESS SPACED ACCORDING TO MAXIMUM LIMITATIONS SHOWN IN FIGURE 2
Cavity Wall Ties FIG. 6
FLASHING INSTALLED IN CONTINUOUS REGLET
WEDGE INSERT ANCHOR
WEEP HOLES @ 24" (610 mm) O.C.
ELASTIC SEALANT AND BACKER ROPE
1/8" (3.2 mm) MINIMUM SPACE BELOW SHELF ANGLE
COMPRESSIBLE MATERIAL (OPTIONAL)
Steel Shelf Angles FIG. 8
Corrosion resistance is usually provided by copper or zinc coatings, or by using stainless steel. To ensure adequate resistance to corrosion, coatings or materials should conform to the following ASTM Specifications: Zinc-coating of flat metal-A 153, Class B-1, B-2 or B-3 Zinc-coating of wire-A 116, Class 3 Copper-coated wire-B 277, Grade 30HS Stainless steel-A 167, Type 304
Flashing. Flashings are generally formed from sheet metals, bituminous membranes, plastics, vinyls or combinations of these, the selection being largely de- termined by cost and suitability. The costs of flashing materials vary widely. It is suggested, however, that only superior materials be selected for flashing, as its replacement in event of failure will be exceedingly expensive. For a more complete discussion of the var-ious types of flashings available, see Technical Notes 7A.
Weep Holes. Weep holes are formed by inserting a material into the mortar joint or by omitting mortar from all or part of a head joint. The forming material may be removed to leave an unobstructed opening, as
OVER OPENINGS AT LINTELS
UNDER SILLS
WEEP HOLES 24" (610 mm) O.C. MAXIMUM ELEVATION AT FLASHING
Flashing and Weep Holes FIG. 7
DOVETAIL SLOT
1/4" (6.4 mm) FLEXIBLE ANCHOR AND DOVETAIL
COMPRESSIBLE FILLER (OPTIONAL)
PLAN VIEW
ELEVATION
Flexible Anchorage FIG. 9
when oiled metal rods are used, or may be left in place, as when plastic tubing or rope wicks are used. Sometimes metal screening, fibrous glass or other materials are placed in open weep holes, but this should not be done indiscriminately. Materials such as metal screen- ing can rust and cause staining of the masonry. Some materials in weep holes such as cotton sash cord, or nylon rope, act as wicks, drawing moisture out of the cavity.
Expansion Joint Material. Expansion joint material in masonry walls can be of 20-oz/ft² (6103 g/m²) copper, premolded compressible elastic fillers, or specially formed rubber and plastic sections. Fiberboard and similar materials are not suitable for this purpose, be- cause they are not compressible. For more information on expansion joints and materials, see Technical Notes 18 Series.
Joint Reinforcement. Joint reinforcement should comply with ASTM A 82. Corrosion resistance should be the same as that noted under Ties and Anchors.
Shelf Angles. Shelf angles should be made of struc- tural steel and properly sized to carry the imposed loads. For harsh climates and exposures, consideration should be given to the use of galvanized shelf angles.
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