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[CCMC 12764-R] CCMC Canadian code compliance evaluation

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

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Compliance opinion

It is the opinion of the Canadian Construction Materials Centre that the evaluated product, when used as a residing underlayment, to cover existing siding while adding thermal insulation in accordance with the conditions and limitations stated in this evaluation, complies with the following codes:

National Building Code of Canada 2015

ID Code provision Solution type
09-25-02-02-00-0- Insulation MaterialsAlternative

National Building Code of Canada 2020

ID Code provision Solution type
92502020000009.25.2.2. Insulation MaterialsAlternative

Ontario Building Code

Ruling No. 09-14-212 (12764-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 2009-08-05 (revised 2018-04-12) 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(s) is/are 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

GreenGuard®/Fanfold Underlayment

Product description

The product is a faced, extruded polystyrene board that is perforated on both sides.

The product is available in 6.35 mm and 9.5 mm thicknesses. As a fanfold, it is 1.2 m high and 15.2 m long, with folds every 600 mm. The underlayment has perforated plastic facers on both sides and an additional perforated foil/plastic facer on one side. The polystyrene core is either green or pink.

An illustration of the product

Figure 1. GreenGuard®/Fanfold Underlayment

Manufacturing plant

This evaluation is valid only for products produced at the following plant:

Product nameManufacturing plant
Winchester, VA, US
GreenGuard®/Fanfold UnderlaymentProduct evaluated by the CCMC

Product evaluated by the CCMC 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 new cladding must be securely fastened either:
    1. directly through the existing structure; or
    2. attached to existing siding if adequate rigidity and supports are provided.
  • The product may only be installed over existing cladding that has a minimum 10-mm air space behind it, which is vented to the exterior and drained. The vented and drained air space must be maintained after the new cladding is installed.
  • The product may be installed with or without a sheathing membrane. If no sheathing membrane is installed and if the existing cladding is susceptible to moisture damage, then the joints of the product must be taped.

Explanatory information

The possibility of moisture accumulation within the wall construction is mainly a function of the physical properties of the insulation being installed and its impact on the thermal, air leakage and vapour diffusion characteristics of the existing wall. Consequently, the potential moisture accumulation resulting from the addition of insulation is very specific to the existing wall construction being retrofitted. This also applies to retrofit construction where insulating sheathing is installed over existing exterior walls.

Adding insulation as sheathing is beneficial only in cases where this insulative sheathing adds thermal resistance without increasing the risk of moisture accumulation. The product can provide additional thermal resistance to the wall assembly without any detrimental effects, if installed properly with knowledge of the existing wall configuration and performance.

  Technical information

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

Evaluation requirements
Criteria number Criteria name
CCMC-TG-072113.10-15ACCMC Technical Guide for Re-Siding Underlayment (Insulative)
CCMC-TG-072113.10-20ACCMC Technical Guide for Re-Siding Underlayment (Insulative)

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

Performance requirements
Table 1. Results of testing the performance requirements of the product
Property Unit Requirement Result
Dimensions (tolerances) As per CCMC Technical Guide Pass
Thermal resistance, min. m2·ºC/W ≥ 0.70 0.723 Footnote (1)
Water vapour permeance, min. ng/(Pa·s·m2) ≥ 130 60-95 Footnote (2)
Dimensional stability, max. % linear change ≥ 1.5 Pass
Flexural strength, min. kPa ≥ 240 661.3 Footnote (3)
Water absorption, max. % by volume ≤ 4 2.72
Compressive strength, min. kPa ≥ 35 50.3

Administrative information

Use of Canadian Construction Materials Centre (CCMC) assessments

This assessment must be read in the context of the entire CCMC Registry of Product Assessments, any applicable building code or by-law requirements, and/or any other regulatory requirements (for example, the Canada Consumer Product Safety Act, the Canadian Environmental Protection Act, etc.).

It is the responsibility of the user to confirm that the assessment they are using is current and has not been withdrawn or superseded by a later version on the CCMC Registry of Product Assessments.


The National Research Council of Canada (NRC) has evaluated only the characteristics of the specific product described 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 (such as authorities having jurisdiction, design professionals and specifiers). This evaluation is valid when the product is used as part of permitted construction, respecting all conditions and limitations stated in the evaluation, and in accordance with applicable building codes and by-laws.

This evaluation is provided without representation, warranty or guarantee of any kind, expressed or implied, and the NRC provides no endorsement for any evaluated product. The NRC accepts no responsibility whatsoever arising in any way from any and all use of or reliance on the information contained herein or the use of any evaluated product. 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.


Une version française de ce document est disponible.
In the case of any discrepancy between the English and French version of this document, the English version shall prevail.


© His Majesty the King in Right of Canada, as represented by the National Research Council of Canada, 2024

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.

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From: National Research Council Canada

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