dampproofing material.]
a.
Coated-Copper Flashing: 0.2 kg 7 ounce, electrolytic copper sheet,
uniformly coated on both sides with acidproof, alkaliproof,
elastic bituminous compound. Factory apply coating to a weight of
not less than 1.8 kg/square meter 6 ounces/square foot
(approximately 0.9 kg/square meter 3 ounces/square foot on each
side).
b.
Copper or Stainless Steel Flashing: Copper, ASTM B 370, minimum
450 g 16 ounce weight; stainless steel, ASTM A 167, Type 301, 302,
304, or 316, 4 mm 0.015 inch thick, No. 2D finish. Provide with
factory-fabricated deformations that mechanically bond flashing
against horizontal movement in all directions. Deformations shall
consist of dimples, diagonal corrugations, or a combination of
dimples and transverse corrugations.
[c.
Reinforced Membrane Flashing: Polyester film core with a
reinforcing fiberglass scrim bonded to one side. The membrane
shall be impervious to moisture, flexible, and not affected by
caustic alkalis. The material, after being exposed for not less
than 1/2 hour to a temperature of 0 degrees C 32 degrees F, shall
show no cracking when, at that temperature, it is bent 180 degrees
over a 2 mm 1/16 inch diameter mandrel and then bent at the same
point over the same size mandrel in the opposite direction 360
degrees.]
2.18
WEEP HOLE VENTILATORS
Weephole ventilators shall be prefabricated aluminum, plastic or wood
blocking sized to form the proper size opening in head joints. Provide
aluminum and plastic inserts with grill or screen-type openings designed to
allow the passage of moisture from cavities and to prevent the entrance or
insects. Ventilators shall be sized to match modular construction with a
standard 10 mm 3/8 inch mortar joint.
PART 3
EXECUTION
3.1
PREPARATION
Prior to start of work, masonry inspector shall verify the applicable
onditions as set forth in ACI 530/530.1, inspection. The Contracting
Officer will serve as inspector or will select a masonry inspector.
3.1.1
Hot Weather Installation
The following precautions shall be taken if masonry is erected when the
ambient air temperature is more than 37 degrees C 99 degrees F in the shade
and the relative humidity is less than 50 percent or the ambient air
temperature exceeds 32 degrees C 90 degrees F and the wind velocity is more
than 13 km/h 8 mph. All masonry materials shall be shaded from direct
sunlight; mortar beds shall be spread no more than 1.2 m 4 feet ahead of
masonry; masonry units shall be set within one minute of spreading mortar;
and after erection, masonry shall be protected from direct exposure to wind
and sun for 48 hours.
3.1.2
Cold Weather Installation
Before erecting masonry when ambient temperature or mean daily air
SECTION 04200
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