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[CCMC 13125-R] CCMC Canadian code compliance evaluation

From: National Research Council Canada

In most jurisdictions this document is sufficient evidence for approval by Canadian authorities.

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Code compliance opinion

It is the opinion of the Canadian Construction Materials Centre that the evaluated product, when used as both exterior decking and as stair treads in accordance with the conditions and limitations stated in this evaluation, complies with the following code:

National Building Code of Canada 2015

ID Code provision Solution type
09-03-02-09-00-0- Termite and Decay ProtectionAlternative
09-04-02-03-00-0- Platforms Subject to Snow and Occupancy LoadsAlternative
09-04-03-01-00-0- DeflectionsAlternative
09-08-09-01-00-0- Loads on Stairs and RampsAlternative
09-23-15-05-00-0- Subfloor Thickness or RatingAlternative

Ontario Building Code

Ruling No. 04-09-113 (13125-R) authorizing the use of this product in Ontario, subject to the terms and conditions contained in the Ruling, was made by the Minister of Municipal Affairs and Housing on 2004-07-20 (revised 2015-04-24) pursuant to s.29 of the Building Code Act, 1992 (see Ruling for terms and conditions). This Ruling is subject to periodic revisions and updates.

The above opinion is based on the evaluation by the CCMC of technical evidence provided by the evaluation holder, and is bound by the stated conditions and limitations. For the benefit of the user, a summary of the technical information that forms the basis of this evaluation has been included.

Product information

Product name

Trex® Transcend® Decking

Product description

The product is wood thermoplastic composite lumber (WTCL) made primarily from equal parts of reclaimed hardwood sawdust and reclaimed/recycled low-density polyethylene. The composite products are manufactured through a continuous extrusion process into planks of solid cross sections. The product is available in 23.7 mm × 137 mm cross sections. The product is intended to be used as stair treads or as exterior decking installed over traditional structural wood framing.

Isometric profile drawing of the deck boards; the minimum spacing between ends of planks, the deck boards, spacing between sides of planks, number of joists per plank, maximum joist spacing and fasteners.
Figure 1. Trex® Transcend® Decking
  1. 3 mm to 5 mm minimum spacing between ends of the planks, depending on the length of the plank and temperature at installation
  2. Trex® Transcend® Decking
  3. 6 mm or 10 mm spacing between sides of the planks, depending on the temperature at installation
  4. Minimum of 3 joists per plank
  5. Maximum joist spacing of 400 mm o.c. for 23.7 mm × 137 mm planks
  6. Joist designed to support applicable loads
  7. Two 76-mm-long fasteners per plank at each intersecting joist

Manufacturing plants

This evaluation is limited to products produced at the following plants:

Product nameFernley, Nevada, United StatesWinchester, Virginia, United States
Trex® Transcend® Decking⦿⦿

⦿ indicates that the product from this manufacturing facility has been evaluated by the CCMC

  Conditions and limitations

The CCMC’s compliance opinion is bound by this product being used in accordance with the conditions and limitations set out below.

  • The product must be installed with supports spaced no greater than 400 mm on center (o.c.). Each plank must be supported by at least three joists.
  • When used as stair treads, the product must be installed with supports spaced no greater than 305 mm.
  • The products must be fastened to the wood joists with fasteners conforming to Article, Standards for Nails and Screws, of Division B of the NBC 2015 that have a corrosion protection coatingFootnote(1) or are made of stainless steel. The planks must be fastened with at least two fasteners per joist and the fasteners must be at least 76 mm long.
  • The product must be installed according to the manufacturer’s installation instructions.
  • The products must be gapped end to end, based on the length of the plank and the temperature at installation in accordance with the manufacturer's recommendations. The end-to-end gapping must be 5 mm for installations below 15°C and 3 mm for installations above 15°C. The width-to-width gapping must be 6 mm for installations above 5°C and 10 mm for installations below 5°C.
  • The products should be installed by a knowledgeable person familiar with the product installation guide.
  • The product’s label or packaging must be identified with the manufacturer’s name or logo and the phrase “CCMC 13125-R.” 

  Technical information

This evaluation is based on demonstrated conformance with the following criteria:

Evaluation requirements
Criteria number Criteria name
CCMC-TG-067314.01-15CCMC Technical Guide for Wood Thermoplastic Composite Lumber Exterior Decking (Solid Cross-Section)

The evaluation holder has submitted technical documentation for the CCMC evaluation. Testing was conducted at laboratories recognized by the CCMC. The corresponding technical evidence for this product is summarized below.

Material requirements
Table 1. Results of testing the physical properties of the product
Property Unit Requirement ResultTable footnote (1)Table footnote (2)
Dimensional change coefficient of linear expansion (thermal) longitudinal cm/cm/°C < 2 × 10-5 5.2 × 10-5Table footnote (3)
cross sectional 7.1 × 10-5Table footnote (3)
coefficient of linear expansion (swelling): oven dry to vacuum pressure soak % < 0.5 by 80% of specimens 0.0
Strength and stiffness modulus of elasticity (MOE) span to depth ratio within 18 to 21 MPa > 750 2 980
modulus of rupture (MOR) > 9 30
Impact resistance (Izod impact, notched) J/m > 53.4 41Table footnote (4)
Hardness (11.28-mm-diameter ball) kN > 1.8 3.8
Creep, recovery and load duration % < 25 for creep 49.1Table footnote (5)
> 75 for recovery 68.7Table footnote (5)
No failure Pass
Strength and stiffness after aging weathering: impact resistance % > 75 of non-weathered value 92
accelerated aging MOE % > 50 of non-aged value 60
MOR 71
Fastener holding capacity nail withdrawal strength N > 600 761 (standard deviation = 35)
lateral nail strength > 720 518Table footnote (6) (standard deviation = 100)
Flame-spread rating smoke development - < 200 120
Report > 500


Table 2. Results of testing the durability, decay, termite and slip resistance properties of the product
Property Requirement Result
Durability MOE Mean percentage losses in MOE and MOR after UV exposure and accelerated aging must be less than or equal to spruce lumber. Pass
Decay resistance % loss in weight Mean percentage losses in weight and compressive strength after exposure to decay-causing fungi must be equal to or better than spruce heartwood. Pass
compressive strength
Termite resistance Rating must be equal to or better than preservative-treated wood conforming to CSA 80.1-M97 Pass
Slip resistance dry condition longitudinal planks > 0.5 ASTM D2394 (05) Parallel to planks Perpendicular to planks
0.43Table footnote (1) 0.52
wet condition 0.32Table footnote (1) 0.39Table footnote (1)
Performance requirements
Table 3. Results of testing the performance of the product under concentrated static loads and impact loads
Property Requirement ResultTable footnote (1)
Minimum ultimate load (kN) Maximum deflection under 0.89 kN load (mm) Ultimate load (kN) Deflection under 0.89 kN load (mm)
Concentrated static load decking at 50°C 2.45 2.4 3.88 2.71
decking at 20°C 4.20 2.7Table footnote (2)
decking at –35°C 4.14 1.06
Impact load of 102 N·m decking at 50°C 1.78 2.4 >1.78 2.3
decking at –35°C 1.12


Table 4. Results of testing the performance of stair treads under a concentrated static load
Property Requirement ResultTable footnote (1)
Minimum ultimate load (kN) Maximum deflection under 1 kN (mm) Applied ultimate load (kN) Deflection under 1 kN (mm)
Concentrated static load stair tread 5Table footnote (2) 0.75 8.75 1.4Table footnote (3)

Administrative information


This evaluation is issued by the Canadian Construction Materials Centre (CCMC), a part of the Construction Research Centre at the National Research Council of Canada (NRC). The evaluation must be read in the context of the entire CCMC Registry of Product Assessments and the legislated applicable building code in effect.

The CCMC was established in 1988 on behalf of the applicable regulator (i.e., the provinces and territories) to ensure—through assessment—conformity of alternative and acceptable solutions to regional building codes as determined by the local authority having jurisdiction (AHJ) as part of the issuance of a building permit.

It is the responsibility of the local AHJs, design professionals, and specifiers to confirm that the evaluation is current and has not been withdrawn or superseded by a later issue. Please refer to the website or contact:

Canadian Construction Materials Centre
Construction Research Centre
National Research Council of Canada
1200 Montreal Road
Ottawa, Ontario, K1A 0R6
Telephone: 613-993-6189
Fax: 613-952-0268

The NRC has evaluated the material, product, system or service described herein only for those characteristics stated herein. The information and opinions in this evaluation are directed to those who have the appropriate degree of experience to use and apply its contents (i.e., AHJs, design professionals and specifiers). This evaluation is only valid when the product is installed in strict compliance with the stated conditions and limitations of evaluation and the applicable local building code. In circumstances where no applicable local building permit is issued and that no confirmation of compliance ‘for use in the intended field application’ is undertaken, this evaluation is null and void in all respects. This evaluation is provided without representation, warranty, or guarantee of any kind, expressed, or implied, and the NRC provides no endorsement for any evaluated material, product, system or service described herein. The NRC accepts no responsibility whatsoever arising in any way from any and all use and reliance on the information contained in this evaluation with respect to its compliance to the referenced code(s) and standard(s). The NRC is not undertaking to render professional or other services on behalf of any person or entity nor to perform any duty owed by any person or entity to another person or entity.


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© 2022 Her Majesty the Queen in Right of Canada, as represented by the National Research Council of Canada.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the CCMC.