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[CCMC evaluation requirements] ANSI/APA PRG 320-2012, Grade E1

From: National Research Council Canada

This document provides a summary of the minimum requirements imposed by the Canadian Construction Materials Centre (CCMC) for all evaluations based on the below criteria document. Additional requirements may be imposed by the CCMC when necessary for a particular evaluation, and are detailed in the individual evaluation.

Criteria document


These evaluations are in accordance with ANSI/APA PRG 320-2012, “Standard for Performance-Rated Cross-Laminated Timber.”This standard applies to cross laminated timber (CLT) panels defined as prefabricated solid engineered wood panels made of at least three orthogonally bonded layers of solid-sawn lumber or structural composite lumber (SCL) that are laminated by gluing the longitudinal andtransverse layers with structural adhesive to form a solid rectangular-shape, straight and plane timber intended for roof, floor, or wall applications.

Grade E1 CLT panels meeting the requirements of ANSI/APA PRG 320 for use in Canada are defined as the following:

  • Grade E1: 1950f-1.7E Spruce-pine-fir MSR lumber in all parallel layers and No. 3 Spruce-pine-fir lumber in all perpendicular layers

These panels are intended for use in dry service conditions only, i.e. conditions where the mean equilibrium moisture content of solid-sawn lumber is less than 16%. The panels are manufactured to meet the standard and are subject to a third-party certification program.

Material requirements

The evaluation holder must demonstrate that the product meets the following requirements (additional requirements may be imposed by the CCMC when necessary, and are detailed in the individual evaluation):

The prescriptive and performance requirements addressed in the standard are summarized below:

Panel Dimensions and Dimensional Tolerances

The standard applies to CLT products that do not exceed a thickness of 508 mm (20 in.).

Table 1. Dimensional tolerances of the CLT panel at the time of manufacturing
Dimension Tolerance (mm (in.)) Footnote (1)
Thickness Stricter of ± 1.6 (1/16) or 2% of specified thickness
Width ± 3.2 (1/8) of specified width
Length ± 6.4 (1/4) of specified length
Squareness ± 3.2 (1/8) difference in diagonals' length
Straightness ± 1.6 (1/16) deviation of edges from a straight line

Component Requirements

Table 2. Tabulated component requirements of lumber and SCL laminations
Property Requirement
Lumber species or species combination Footnote (1) Any species or species combination recognized by the Canadian Lumber Standards Accreditation Board under CSA O141 Footnote (2)
Minimum specific gravity 0.35
Minimum lumber grades Footnote (1) parallel layers Footnote (3) 1200f-1.2E MSR or Visual grade No. 2
perpendicular layers Footnote (4) Visual grade No. 3

Lamination sizes

major strength direction Lamination width ≥ 1.75 × lamination thickness for parallel layers
minor strength direction Lamination width ≥ 3.5 × lamination thickness for the perpendicular layers Footnote (5)
both directions 51 mm (2 in.) ≥ lamination net thickness Footnote (5) ≥ 16 mm (5/8 in.)
Moisture content Footnote (6) 12 ± 3%


surface preparation Planed and cleaned
dimensional tolerance – variation in thickness ± 0.2 mm (0.008 in.) across the width
± 0.3 mm (0.012 in.) along the length
Standards on requirements for adhesives CSA O112.10
Sections 2.1.3 and 3.3 of AITC 405 Footnote (7)
Section of DOC PS1 Footnote (8)
Lamination Joints end joints Section 9.5 of CSA O177
edge and face joints Sections 9.2 and 9.3 of CSA O177 except for shear strength

CLT Performance Criteria

The structural performance of every layup must be evaluated as per the standard (with some exceptions). The minimum required characteristic test values that the CLT products have to meet are shown in Table 3, below, which is reproduced from the standard. The structural performance must be evaluated and approved by a third party certification agency. Custom CLT grades are also permitted by the standard

Table 3. Required characteristic test values - Grade E1 Footnote (1) Footnote (2)
Major Strength Direction (MPa) Minor Strength Direction (MPa)
fb,0 E0 ft,0 fc,0 fv,0 fs,0 fb,90 E90 ft,90 fc,90 fv,90 fs,90
28.2 11 721 19.9 23.6 2.9 0.97 7.2 8 274 3.6 8.5 2.9 0.97


The CLT components are qualified in accordance with the requirements summarized above. The standard includes requirements for plant pre-qualification. The CLT qualification tests include qualification of effective bond area, structural performance, and mechanical properties. The standard also described process change qualification requirements as well as mill specifications.

Quality Assurance

The standard requires an ongoing quality assurance program to be documented in an in-plant manufacturing standard that is approved by a third party certification agency. The standard also describes the requirements for ongoing quality assurance testing for end, face and edge joints in laminations, minimum effective bonding area maintained, lamination grade limits, glue skip in the face bondline, finished product inspections and minor variations.

Design Properties

The limit states design properties are provided in the table below, and the limit states design resistances are shown in Table 5, below. These tables are reproduced from the standard.

Table 4. Specified strength and modulus of elasticity - Grade E1 Footnote (1) Footnote (2)
Major Strength Direction (MPa) Minor Strength Direction (MPa)
fb,0 E0 ft,0 fc,0 fv,0 fs,0 fb,90 E90 ft,90 fc,90 fv,90 fs,90
28.2 11,700 15.4 19.3 1.5 0.50 7.0 9,000 3.2 9.0 1.5 0.50
Table 5. Limit states design bending resistances - Grade E1 Footnote (1)
CLT thickness (mm) Lamination Thickness (mm) in CLT Layup Major Strength Direction Minor Strength Direction
(106 N-mm/m)
(109 N-mm2/m)
(106 N/m)
(106 N-mm/m)
(109 N-mm2/m)
(106 N/m)
105 35 35 35 42 1 088 7.3 1.4 32 9.1
175 35 35 35 35 35 98 4 166 15 12 836 18
245 35 35 35 35 35 35 35 172 10 306 22 28 3 183 27

© American National Standards Institute. This information is reproduced from the referenced standard published by the American National Standards Institute (ANSI). The full version of the Standard should be referenced, and can be obtained from ANSI.

Installation requirements

The CCMC requires that evaluation holders provide instructions for the installation of the product(s) that:

Manufacturing requirements

The CCMC requires that evaluation holders, at a minimum, demonstrate that the associated production process:

Labelling requirements

The CCMC requires that evaluation holders ensure that product labels:

In addition, the standard requires the CLT products to bear the stamp of a third party certification agency that either inspects the manufacturer or has performed sampling and testing of the finished product in the shipment being certified for conformance with the standard.

In addition the product must be identified with the following marks and information:

The standard also specifies that the spacing of markings be no more than 2.4 m (8 ft.).

  1. panel dimensions and dimensional tolerances;
  2. component requirements:
    1. lumber laminations,
    2. structural composite lumber (SCL) laminations,
    3. adhesives, and
    4. lamination joints;
  3. CLT performance criteria:
    1. layup requirements, and
    2. structural performance requirements;
  4. qualification and product marking;
  5. quality assurance; and
  6. design properties.
    1. CLT grade;
    2. CLT thickness or identification;
    3. mill name or identification number;
    4. the name of third party certification agency or logo;
    5. the symbol of ANSI/APA PRG 320;
    6. any manufacturer designation which has to be separated from the grade-marks or trademarks of the certification agency by not less than 152 mm (6 in.); and
    7. “Top” stamp on the top face of custom CLT panels used for roof or floor if manufactured with an unbalanced layup.

Classification information

Products falling within the scope of this document are commonly classified by:


  • 06 10 00 Rough Carpentry
  • 06 17 19 Cross-Laminated Timber

Published CCMC evaluations

The following products have been evaluated to these requirements by the CCMC:

CCMC number:Manufacturer:Product names:
13654-LNordic Structures Nordic X-Lam
14041-LStructurlam Products LP CrossLam

Code references

This standard is not referenced in the National Building Code of Canada