21/10/2011

1

Structural Connectors and Their Fasteners

Brent Bunting, P.Eng

Agenda

• Introduction to Simpson Strong-Tie• The Building Code• Nails, Wood Screws and Bolts• Limit States Design Catalogue• Limit States Design Catalogue

– General Information– Installation Guidelines

• Misinstallations• Corrosion of Connectors With PTW

Who We Are Humble Beginnings

SST Global Research and Development

21/10/2011

2

Literature www.strongtie.com

Connectors The Building Code

CSA Standard O86

• 10.10 Joist Hangers

CSA Standard O86

• Sheet steel shall be hot-dipped galvanized(10.10.1.3)

21/10/2011

3

CSA Standard O86

• The hanger shall be at least half the depth of the joist unless the joist is prevented from twisting by other means.(10.10.1.4(a))

• We recommend 60%.

CSA Standard O86

• The hanger shall be fastened to boththe joist and the header.(10.10.1.4(b))

CSA Standard O86

• I-joist hangers that do not use bearing stiffeners shall be high enough to support the top flange.(10.10.1.4(c))

CSA Standard O86

• Where I-joists are used as the header, backer blocks shall be provided between the webbetween the web and the face mount hanger. (10.10.1.4(d))

• We recommend backer blocks on both sides. (APA)

CSA Standard O86

• When an I-joist supports a top mount hanger, filler blocks shall be used between theused between the top and bottom flange of the I-joist. Blocks shall be tight to the bottom of the top flange.(10.10.1.4(e))

CSA Standard O86

• Testing must be done in accordance with ASTM Standard D1761.(10.10.1.5)

21/10/2011

4

Fasteners

• Nails– For all types of connectors

• Wood ScrewsP i t f t– Proprietary screws for some connectors

• Bolts– For special high capacity connections

The Building Code

• 9.23.3.1.(1)– “…nails specified in this section shall be

common steel wire nails or common spiral nails conforming to CSA B111…”p g

CSA B111

• Wire Nails, Spikes and Staples– Dimensional information

• Diameter (gauge)• Diameter (gauge)• Length• Head size

– Material requirements• 90º bend test

CSA B111

• Lists 37 different types of nails/spikes– Table 1 – Common Round Wire Nails– Table 22 – Common Spiral Nails

– Table 12 – Round Wire Box Nails• Gun Nails

CSA B111

Nail Length(in)

Nail Diameter (in)Common Spiral Box

2½ 0.128 0.110 0.1043 0.144 0.122 0.116

3¼ 0.144 0.122 0.1283½ 0.160 0.152 0.128

Nail Nomenclature

• Penny weight system– 16d nail = 3½” long– 16 pence for 100 nails

“d” = denarius– d = denarius

• ASTM D1667– 16d common ≠ 16 box

(0.160” vs. 0.128”)

21/10/2011

5

Nails

• Shear capacity (lateral) is based on:– Relative density of the lumber– Thickness of side member

Depth of penetration into the header– Depth of penetration into the header– Tensile capacity of steel side plate– Bending strength of the nail– Cross sectional area of the nail

Effect of Nail Penetration

CSA O86-01 CSA O86-09*

< 8D Penetration = 0%8D Penetration = 100%

< 5D Penetration = 0%5D Penetration = 70%8D Penetration = 84%

Penetration

D

12D Penetration = 100%

*3” common wire nail with 14 gauge steel side plates

Effect of Nail Penetration Effect of Nail Penetration

Effect of Nail Penetration Effect of Nail Penetration

21/10/2011

6

Effect of Nail Penetration Nails

Specialty Short Nails

• 10d x 1½” nail is NOT a “Joist Hanger Nail”

• CAN be used when attaching to a single plyattaching to a single ply header at a reduced capacity

• Same diameter as 10d common wire nail

Nails

Gun Nails Wood Screws

• ASME Standard B18.6.1

21/10/2011

7

Wood Screws

2.6 Material

Wood screws shall be supplied in steel, corrosion resistant steel brass aluminumcorrosion resistant steel, brass, aluminum alloy, or other materials as designated by the purchaser. Unless otherwise specified, no chemical or physical requirements shall apply.

Wood Screws

• Tapered heads will damage connector holes

Proprietary Connector Screws

• SD Structural Connector screws– Hex head

• #9 x 1½• #9 x 2½#9 x 2½• #10 x 1½• #10 x 2½

– Approved for use with some connectors

SD Structural Connector Screws

Proprietary Connector Screws

• Strong Drive Screws (SDS)– Hex head– ¼” diameter

Nine lengths– Nine lengths• Only to be used with

specific connectors• Also used to laminate

members together

Generic Wood Screws

21/10/2011

8

Bolts

• All bolts are ASTM A307 or Grade 2.– Nut and washer are always

requiredF ifi t l– For specific connectors only

Bolts

• Carriage bolts are not allowed

• Lag Screws are not allowed

Connector Manufacturers Limit States Design Catalogue

• CCMC product evaluation reports.

General Notes General Notes

• Load Duration FactorsKD=1.00 – Standard Duration for floors, and

roofs.KD=1.15 – Short Term for wind and

earthquake onlyearthquake only.

21/10/2011

9

General Notes

• Capacities assume Dry Service Condition (KS=1.00).

• Other service conditions may mean a reduction in capacity.

• Wet service condition means a reduction of 1/3rd in capacity for nail or screw connections (i.e. multiply table value by 0.67).

General Notes

• Do not bend connectors in the field unless the catalogue permits it.

• Connectors that can be bent in the field can only be bent once.

General Notes

• Built up members must be fastened together to act as one unit.

• Load transfer between plies is not done by the hanger.

General Notes

• Not all LVL is the same

General Notes

• Always install the correct quantity, type and size of fastener specified in the catalogue.

• We always specify common wire nails.

Connector Holes

21/10/2011

10

General Installation Information Top Flange Hangers

Hanger Rotation Joist Connection

Joist Connection IUS / ITS

21/10/2011

11

Wood Nailers Wood Nailers

Wood Nailers LSSU - Field Adjustable

Misinstallations Misinstallations

21/10/2011

12

Misinstallations Misinstallations

Misinstallations Misinstallations

Misinstallations Misinstallations

21/10/2011

13

Misinstallations Misinstallations

Misinstallations Misinstallations

Misinstallations Misinstallations

21/10/2011

14

MisinstallationsCorrosion

As of December 31, 2003 CCA is mainly restricted to below grade applications.

Corrosion

As a result, the Wood Preservatives industry must use alternative chemicals to treat wood.

• The two main alternative chemicals in Canada are:– Alkaline Copper Quat (ACQ-C, ACQ-D)– Copper Azole (CBA-A, CA-B)

Corrosion

• Each has substantially more copper (Cu) in its formulation than CCA.

• Copper + Zinc + moisture = Bad

Corrosion Corrosion

21/10/2011

15

Corrosion

• Always compare recommendation from treated wood supplier, chemical manufacturer and component manufacturer and use most conservative suggestion.

Corrosion

• Do NOT mix metals.

• For galvanized connectors use galvanized fasteners.fasteners.

• For stainless steel connectors use stainless steel fasteners.

• Do NOT use aluminum with preservative treated woods.

Corrosion THANK YOU