[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

Number

ANSI/APA PRG 320-2012, Grade E1

Title

Standard for Performance-Rated Cross-Laminated Timber

Document

Standard

Publisher

American National Standards Institute

Scope

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
Minimum lumber grades ^{Footnote (1)}	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%
Face-bonding	surface preparation	Planed and cleaned
	dimensional tolerance – variation in thickness	± 0.2 mm (0.008 in.) across the width
	dimensional tolerance – variation in thickness	± 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 6.1.3.4 of DOC PS1 ^{Footnote (8)}
Lamination Joints	end joints	Section 9.5 of CSA O177
Lamination Joints	edge and face joints	Sections 9.2 and 9.3 of CSA O177 except for shear strength

Notes to table:

Footnote 1

This requirement does not apply to SCL laminations.

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Footnote 2

Within a single layer of the CLT panel, the same species or combination thereof has to be used. However, species can be different between adjacent layers.

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Footnote 3

Parallel layers refer to the layers that will be parallel to the load direction, i.e., parallel to the major strength direction.

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Footnote 4

Perpendicular layers refer to the layers that will be perpendicular to the load direction, i.e., perpendicular to the minor strength direction.

Return to footnote 4 referrer

Footnote 5

This width is only required when the parallel layers are not edge bonded. Furthermore, an alternative is allowed by the standard to forgo this requirement by demonstrating interlaminar shear strength and creep performance through specified testing.

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Footnote 6

This requirement refers to the moisture content at the time of manufacturing.

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Footnote 7

The requirements for heat durability in ASTM D7247.

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Footnote 8

Evaluation for heat performance.

Return to footnote 8 referrer

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)
f_b,0	E₀	f_t,0	f_c,0	f_v,0	f_s,0	f_b,90	E₉₀	f_t,90	f_c,90	f_v,90	f_s,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

Notes to table:

Footnote 1

f_b,0 is the characteristic bending strength parallel to the major strength direction of the CLT.

E₀ is the modulus of elasticity in bending parallel to the major strength direction of the CLT.

f_t,0 is the characteristic tensile strength parallel to the major strength direction of the CLT.

f_c,0 is the characteristic compressive strength parallel to the major strength direction of the CLT.

f_v,0 is the characteristic shear strength parallel to the major strength direction of the CLT.

f_s,0 is the characteristic interlaminar (rolling) shear strength parallel to the major strength direction of the CLT.

f_b,90 is the characteristic bending strength perpendicular to the major strength direction of the CLT.

E₉₀ is the modulus of elasticity in bending perpendicular to the major strength direction of the CLT.

f_t,90 is the characteristic tensile strength perpendicular to the major strength direction of the CLT.

f_c,90 is the characteristic compressive strength perpendicular to the major strength direction of the CLT.

f_v,90 is the characteristic shear strength perpendicular to the major strength direction of the CLT.

f_s,90 is the characteristic interlaminar (rolling) shear strength perpendicular to the major strength direction of the CLT.

Return to footnote 1 referrer

Footnote 2

Tabulated values are test values and shall not be used for design.

Return to footnote 2 referrer

Qualification

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)
f_b,0	E₀	f_t,0	f_c,0	f_v,0	f_s,0	f_b,90	E₉₀	f_t,90	f_c,90	f_v,90	f_s,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
CLT thickness (mm)	═	┴	═	┴	═	┴	═	f_bS_eff,0 (10⁶ N-mm/m)	EI_eff,0 (10⁹ N-mm²/m)	GA_eff,0 (10⁶ N/m)	f_bS_eff,90 (10⁶ N-mm/m)	EI_eff,90 (10⁹ N-mm²/m)	GA_eff,90 (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

Note to table:

Footnote 1

The symbols that were previously used in Tables 3 and 4 are as defined in Note (1) to Table 3. Other symbols are defined as follows:

S_eff is the effective section modulus (mm³/m) of the composite CLT section for calculating the moment capacity of CLT.

I_eff is the effective moment of inertia (mm⁴/m) of the composite CLT section for calculating the bending stiffness of the CLT.

G₀ is the modulus of rigidity in parallel to the major strength direction of the CLT (MPa). In the standard, G₀ = E₀/16 for lumber.

G₉₀ is the modulus of rigidity in perpendicular to the major strength direction of the CLT (MPa). In the standard, G₉₀ = G₀/10 for lumber.

A_eff is the effective cross sectional area (mm²/m) of the composite CLT for calculating the interlaminar shear capacity of the CLT.

Return to footnote 1 referrer

© 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:

do not contravene the National Building Code of Canada, or any provincial or territorial building codes; and
meet the requirements of CCMC minimum documentation requirements.

Manufacturing requirements

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

is operated under a documented quality system; and
meets the minimum requirements of the CCMC minimum documentation requirements.

Labelling requirements

The CCMC requires that evaluation holders ensure that product labels:

reference the associated CCMC number or mark; and
meet the requirements of CCMC minimum documentation requirements.

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.).

panel dimensions and dimensional tolerances;
component requirements:
1. lumber laminations,
2. structural composite lumber (SCL) laminations,
3. adhesives, and
4. lamination joints;
CLT performance criteria:
1. layup requirements, and
2. structural performance requirements;
qualification and product marking;
quality assurance; and
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:

MasterFormat®

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-L	Nordic Structures	Nordic X-Lam
14041-L	Structurlam Products LP	CrossLam

Code references

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

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

Criteria document

Scope

Material requirements

Panel Dimensions and Dimensional Tolerances

Component Requirements

CLT Performance Criteria

Qualification

Quality Assurance

Design Properties

Installation requirements

Manufacturing requirements

Labelling requirements

Classification information

MasterFormat®

Published CCMC evaluations

Code references