Design Mercer CLT to CSA O86

Mercer’s Canadian cross-laminated timber is manufactured by OK Laminators (dba Mercer Mass Timber, Okanagan Falls, British Columbia). It is recognized under APA Product Report PR-L314(C), rated to ANSI/APA PRG-320. SPEC Toolbox designs the panels to CSA O86, in limit states design.

The integration covers the OK Laminators CLT, cross-laminated spruce-pine-fir (SPF) laminations, in visual and E-rated grades.

• Visual grades V2.1, V2M1, V2M1.1, V2M2, V2M2.1 and V2.1M1, and E-rated grades E1M3, E1M3.1, E1M3.2, E1M4, E1M5, E1M6 and E1M7 (to 2100f-1.8E SPF).
• Layups from 87 to 315 mm thick, including XL layups with doubled outer laminations; panels up to 3.05 m wide and 12.2 m long.
• Applications in floor, roof and wall panels; SPF laminations may be replaced with lumber of equal or greater design properties.

At a glance, in the Canadian scope the OK Laminators panels support:

• Load-bearing floors, roofs and walls.
• Limit states design (LSD).
• Dry service (average solid-sawn moisture content 15 percent or less, not exceeding 19 percent).

• Visual and E-rated SPF grades. From the visual V2 series to the E-rated E1M7 (2100f-1.8E), with LSD specified strengths and unfactored resistances in the major and minor directions.
• XL layups. Selected layups double the outer laminations to raise major-direction resistance for a given thickness.
• In-plane shear values. Specified edgewise (in-plane) shear strengths are given for the panels, for diaphragm and in-plane design under CSA O86.
• Fire design to CSA O86 Annex B. Fire exposure is designed by the residual-cross-section method of CSA O86 Annex B.

The OK Laminators panels are available across the SPEC Toolbox CLT modules, worked to CSA O86:

• CLT floor and CLT wall.

and in the connection modules:

• the screw connection module and the panel-to-panel connection details (spline, butt joint and half-lap);
• CLT floor-to-glulam beam, CLT floor-to-floor and CLT wall-to-wall connections.

Panel behaviour is taken from the integrated database with the LSD specified values of PR-L314(C), using the grade relative density (0.42 to 0.47) for fastener design.

Design follows CSA O86 (CSA O86:19, Engineering Design in Wood, limit states design) under the National Building Code of Canada. APA Product Report PR-L314(C) publishes LSD specified strengths and unfactored resistances for the OK Laminators CLT, rated to ANSI/APA PRG-320: effective bending capacity, bending and shear stiffness, shear and edgewise (in-plane) shear, in the major and minor directions, for the SPF V-series and E-series grades. Factored resistances are obtained with the CSA O86 modification factors, and the lumber size factor is not applied. The laminations are SPF (relative density 0.42, or 0.47 for the higher E-rated major laminations). The evaluation is for dry service; fire is designed by the residual-cross-section method of CSA O86 Annex B. Connection design follows CSA O86.