SpiderLath – Installation Procedures
May 8, 2009
ATTACHMENT 2
(Installation Instructions)
To provide evidence of compliance with AC-275 (Section 2.1.2), please find outlined below the following information:
Installation procedures for SpiderLath (Patent Pending)
Standards and References
ASTM F 1667 – Standard Specification for Driven Fasteners, Nails, Spikes and Staples
ASTM C 270 – Standard Specification for Mortar for Unit Masonry.
ASTM C 144 – Standard Specification for Aggregate for Masonry Mortar
ASTM C 150 – Standard Specification for Portland Cement.
ASTM C 778 - Standard Specification for Standard Sand
ASTM C 207 – Standard Specification for Hydrated Lime for Masonry Purposes.
1. Installation
The lath is to be installed with the standoff strips against the substrate in any direction to create a void that is to be filled with the mortar scratch coat. The lath is to be installed with a minimum 2 inch (51 mm) overlap at horizontal and vertical edges. The lath shall be applied flat and stretched tight against the substrate.
2. Fasteners
A. Wood Studs
a. Corrosion resistant wide crown staples (minimum of ¾ inch crown width) for wood stud applications; achieve penetration into wall
stud a minimum of ¾ inch and spacing of staple 6 inches on perimeter and 6 inches in the field into the strip system (rubber strips).
b. Staple must be applied only into the strip system to ensure damage created by the staple, into the water barrier, can compress and
seal intrusion made by the staple to prevent moisture damage to the substrate.
c. In Open Stud framing (wood), length of staple shall be long enough to penetrate the wood stud by at least ¾ inch.
d. In Rigid Sheathing over wood framing, length of staple shall be long enough to penetrate wood stud by at least ¾ inch.
B. Metal Studs
a. For metal surfaces and metal stud applications, No. 6 Type S self tapping screw with 2 -inch-diameter (52 mm) Wind-Lock wind-devil 2
fastening system of sufficient length to penetrate at least 3/8” beyond the metal surfaces.
b. Screw must be applied only into the strip system to ensure damage created by the screw, into the water barrier, can compress and seal intrusion made by the screw to prevent moisture damage to the substrate.
3. Mortar
A. Masonry mortar minimum: masonry Type S mortar, ASTM C 270
B. Masonry Sand: Natural or manufactured sand per ASTM C 144, that is clean and free from deleterious amounts of loam, clay, silt, soluble salts and organic matter.
C. Pigment: Mineral oxide pigments (powder or liquid), ASTM C979
D. Water: Potable water clean and free from injurious amounts of oils, acids, alkali’s, salts, organic minerals or other deleterious substances.
4. Applying Scratch Coat
A. Apply mortar scratch coat with sufficient pressure to force mortar through openings to completely fill area between lath and substrate. Apply a minimum of ¼ inch mortar to fill area between lath and substrate made by furring strip system and a minimum of ¼ inch of mortar to outside of lath.
B. Scarifying the surface of the mortar scratch coat in a horizontal direction may be performed to increase the surface bonding properties when veneer masonry unit is applied.
C. Permit the mortar scratch coat to cure to a point where veneer masonry unit can be applied without damage to the scratch coat. Cure time varies with ambient temperature and humidity.
2.1.2 Installation Limitations
2.1.2-B Limitations:
A. Weight of veneer stone or exterior cladding must be under 15 lbs per sf
B. Do not install on Soffit
C. SpiderLath must be installed with the Strips against substrate
ENGINEERING • MATERIALS TESTING