Wood Construction Connectors - Page 8

®	Sources of Deflection at Shearwall Holdown Connections

A. Stud bolt holes: bolt slip can occur at holdown stud bolts.

B. Oversized stud bolt holes: increased bolt slip can occur if oversized holes are drilled through the stud for holdown stud bolts (oversized holes are when the diameter of the hole is greater than the bolt diameter plus 1/16"  inch per 1997 NDS, section 8.1.2.1).

C. Eccentricity in stud: when a holdown is installed on only one side of the stud, an eccentricity exists during  loading which can cause more movement in the shearwall system.

D. Nut spin: unrestrained anchor bolt nuts can spin loose during cyclic loading; the use of steel nylon locking nuts or thread adhesive may prevent nut spin.

E. Lack of nut tightening: additional movement can occur when nuts are not tightened sufficiently. Retightening bolts before covering wall may prevent this.

F. Deflection of the holdown: deflection can occur in the holdown under load caused by stresses due to earthquake or high wind.

G. Vertical deflection at the holdown seat caused by stud rotation: lateral displacement at the top of the wall rotates the stud around its base causing the holdown base plate to displace vertically.

H. Shrinkage: wood shrinkage can occur due to drying of the sill plate, rim joist, and/or top plate; nuts may require retightening after wood shrinkage.

I. Localized wood crushing at stud bolt holes: uplift forces on the bolts can cause localized wood crushing at bolt bearing locations. The use of larger bearing plates may prevent this.

J. Localized crushing caused by dead and live loads: wood at the end of the studs (sill plates, rim joists, etc.) may crush under normal dead and live loading; additional compressive forces due to overturning during earthquake and high wind loads add to the deflection.

CONVERSION CHARTS

US Standard Steel Gauge Equivalents in Nominal Dimensions

Steel thickness may vary according to industry mill standards.

Slope Conversion

Optional Nails for face mount hangers and straight straps

1. 10d x 1-1/2"or 16d x 2-1/2" nails may not be substituted for joist nails in double shear hangers (i.e. LUS, HUS, HHUS). Contact factory for exceptions.

2. 10d x 1-1/2" nails may not be substituted for face nails on skewed LSU and LSSU hangers.

3.This table does not apply to specials (see Hanger Options), or steel thicker than 10 gauge.

Metric Conversion

Bolt Diameter

NAILING IDENTIFICATION

Dome Nailing This feature  guides the nail into the joist and header at a 45° angle. U.S. Patent  5,603,580	Double Shear Nailing The nail is installed into the joist and header, distributing the load through two points on each joist nail for greater strength. U.S. Patent 4,480,941;   Canada Patent 1,193,418	Positive Angle Nailing (PAN) Provided when wood splitting may occur, and to speed installation. U.S. Patent 4,291,996
Speed Prongs Used to temporarily position and secure the connector for easier and faster installation.	Triangle Holes Provided on some products in addition to round holes. Round and triangle holes must be filled to achieve the published maximum load value.	Obround Holes Used to provide easier nailing access in tight locations.
Diamond Holes Optional holes to temporarily secure connectors to the member during installation.

CORROSION RESISTANCE

Connectors are steel and will corrode and lose load-carrying capacity if exposed to ocean salt air, corrosive fire-retardant chemicals, fertilizers, or other substances that adversely affect steel. Simpson Strong-Tie^® offers two additional coating options and stainless steel products to give you special corrosion-resistant NO-EQUAL quality. In corrosive environments, especially for connectors that are not exposed to rain or periodic washing, deterioration will occur at a faster rate. The service life of galvanized connectors in a temperate marine environment can be greatly improved by homeowner maintenance. Fasteners of comparable material should be used to install the product. Contact your Simpson representative for product availability, ordering information and lead times. Pressure-preservative treated and fire-retardant treated wood can be caustic to zinc coated (or galvanized) steel. Galvanized connectors should not be placed in contact with treated wood that has not been properly air-seasoned or properly kiln-dried. See material supplier for specific recommendations.

Products are hot-dip galvanized after fabrication. The coating weight increases with material thickness. Hot-dip galvanizing is available for many products, and require galvanized 3 fasteners.

3 times the zinc of our standard galvanized products! Z-MAX meets all catalog load specifications listed for the regular products and all published building code reports. Require galvanized fasteners.

Connectors are manufactured from Type 316 stainless steel, and provide greater durability against corrosion. Stainless steel nails should be used with stainless steel products, and are available from Simpson.