Report 138 Plywood Diaphragms - Panelized

1 50080702030401060905023876941 RESEARCHREPORTR eport 138 Plywood Diaphragmsby John R. Tissell, and James R. Elliott, Services DivisionTHE ENGINEEREDWOOD ASSOCIATIONAPAWood is the right choice for a host of construction applications. It is theearth s natural, energy efficient and renewable building wood is a better use of miracle in today s woodproducts is that they make more efficient use of the wood fiber resource to make stronger Plywood , oriented strand board, I-joists, glued laminatedtimbers, and laminated veneer lumber. That s good for the environment, and good fordesigners seeking strong, efficient, and striking building few facts about wood.

2 We re not running out of of the United States land base 731 million acres is covered by forests. About two-thirds of that 731million acres is suitable for repeated planting and harvesting of timber. Butonly about half of the land suitable for growing timber is open to of that harvestable acreage also is open to other uses, such ascamping, hiking, and hunting. Forests fully cover one-half of Canada s land mass. Of this forestland, nearly half is considered productive, or capable of producing timber on asustained yield basis. Canada has the highest per capita accumulation of protected naturalareas in the world areas including national and provincial parks.

3 We re growing more wood every landowners plant more than two billion trees every year. In addition, millions of trees seednaturally. The forest products industry, which comprises about 15 percentof forestland ownership, is responsible for 41 percent of replanted forestacreage. That works out to more than one billion trees a year, or aboutthree million trees planted every day. This high rate of replanting accounts for the fact thateach year, 27 percent more timber is grown than is harvested. Canada s replanting recordshows a fourfold increase in the number of trees planted between 1975 and 1990. Manufacturing wood is energy products made up 47 percent of allindustrial raw materials manufactured in theUnited States, yet consumed only 4 percentof the energy needed to manufacture allindustrial raw materials, according toa 1987 study.

4 Good news for a healthy every ton of wood grown, a young forest produces tons of oxygen and absorbs tons ofcarbon , the miracle material for the environment, for design, and for strong, lasting :The recommendations inthis guide apply only topanels that bear the APAtrademark. Only panelsbearing the APA trademarkare subject to theAssociation s qualityauditing SHEATHINGEXPOSURE 1 SIZED FOR SPACING32/16 15/32 INCH000PS 1-95 C-D PRP-108 THE ENGINEEREDWOOD ASSOCIATIONAPAWOODThe Miracle Material Percent ofPercent ofMaterialProductionEnergy UseWood474 Steel2348 Aluminum28 CONTENTSR ecommended Shears for High-Load Wood Structural PanelDiaphragms.

5 2 Background ..4 Objective ..4 Test Setup ..4 Test Procedure ..5 Materials and Specimens ..6 FramingChordsPlywoodControl diaphragm Panelized ConstructionDiaphragm No. 1 ..8 PurposeConstructionDesignTest Results and DiscussionHigh-Load diaphragm Two-Layer Panelized ConstructionDiaphragm No. 2 ..10 PurposeConstructionDesignTest Results and DiscussionHigh-Load Diaphragms Conventional ConstructionDiaphragm No. 7 ..12 PurposeConstructionDesignTest Results and DiscussionCorrelation with Table 1 ValuesDiaphragm No. 8 ..15 PurposeConstructionDesignTest Results and DiscussionCorrelation with Table 1 ValuesDiaphragm No.

6 9 ..17 PurposeConstructionDesignTest Results and DiscussionCorrelation with Table 1 ValuesPLYWOOD DIAPHRAGMSBy John R. Tissell, and James R. Elliott, accepted Plywood diaphragm construction isapplicable for design shears significantly higher than thosepreviously published. Multiple rows of fasteners in wideframing members are used to develop the higher shear loadssometimes required for buildings in Seismic Zone 4. Thisreport details the design and testing of eleven Diaphragms ,up to the limiting shear stress of the Plywood . The effects ofopenings in the diaphragm and field gluing of plywoodsheathing are also investigated.

7 diaphragm No. 10 ..18 PurposeConstructionDesignTest Results and DiscussionCorrelation with Table 1 ValuesDiaphragms With OpeningsDiaphragm No. 3 ..19 PurposeConstructionDesignTest Results and DiscussionDiaphragm No. 4 ..20 PurposeConstructionDesignTest Results and DiscussionField-Glued DiaphragmsDiaphragm No. 5 ..22 PurposeConstructionDesignTest Results and DiscussionDiaphragm No. 6 ..23 PurposeConstructionDesignTest Results and DiscussionDiaphragm With Framing Spaced 5 Ft No. 11 ..24 PurposeConstructionDesignTest Results and DiscussionSummary ..26 Conclusions ..26 Literature Cited ..29 Appendix A Summary of Previous diaphragm Tests.

8 30 Appendix B Supplemental Fastener Tests ..36 Appendix C Derivation of Design Shear Equation for Discontinuous Interior Panel Joints ..39 Appendix D Load-Deflection Curves for Test Diaphragms ..41 Appendix E Analysis of Chord Forces and Shears for diaphragm 4 ..522 Plywood DiaphragmsRECOMMENDED SHEARS FOR HIGH-LOAD WOODSTRUCTURAL PANEL DIAPHRAGMSThe table on the following page of allowable design shears forhigh-load wood structural panel Diaphragms has been derivedfrom test results given in the body of this Report , with suitablereference to all previous tests of horizontal Plywood Diaphragms .(See Appendix A for a table of previously accepted design shearsand a summary of previous diaphragm tests.)

9 Tabulated shearsare for wind or seismic loading. Reduce values 25% for normal load : Allowable high-load shear values in Table 1 werederived based on the principles in this Report and EuropeanYield Model (EYM) provisions for fastener lateral loads, perthe 1997 Edition of the National Design Specification (19).*See ICBO ES Evaluation Report No. 1952 (20).Allowable design shears assume that all framing, splices, ties,hold-downs and other connections are adequately designedand detailed for such loads.*Italicized numbers in parentheses refer to literature 1 ALLOWABLE SHEAR IN POUNDS PER FOOT FOR HIGH-LOAD HORIZONTAL BLOCKED Diaphragms WITH FRAMING OF DOUGLAS FIR, LARCH OR SOUTHERN PINE1 FOR WIND OR SEISMIC LOADING2 FastenerMinimumCases 1 and 24 NominalFastener spacing per line at boundariesMinimumMinimumWidth of4 inches2-1/2 inches2 inchesPenetrationNominalFramingFastener spacing per line at other panel edgesPanelin FramingThicknessMemberLines of644332 Grade3 Type(inches)(inch)(inches)

10 Fastenersinches inchesinches inchesinches inches32605815875 1,150 15/32427009151,005 1,290 43875 1,2201,285 1,395 10d32670880965 1,255 common1-5/819/32427809901,110 1,440 nails43965 1,3201,405 1,790 Structural I327309551,050 1,365 23/3242855 1,0701,210 1,565 431,050 1,4301,525 1,800 326006008609601,060 1,20014 ,160 1,2951,295 1,400staples2326006008759601,075 1,20019/32438759001,175 1,4401,475 1,79532525725765 1,010 15/3242605815875 1,105 43765 1,0851,130 1,195 10d32650860935 1,225 common1-5/819/32427559651,080 1,370 Othernails43935 1,2901,365 1,485 APA327109551,020 1,335 Grades23/3242825 1,0301,175 1,445 431,020 1,4001,480 1,565 32540540735865915 1,08014 ,005 1,1051,105 1,195staples2326006008659601,060 1,20019/32438659001,1301,43051,37051,485 5 For SI.