• 2024 URL Darrel's listing

    Posted on Jun 24, 2024


    HORACE (O_RAS) is proud to present the Latest edition 2024 URL listing by one of the most engaged professionnal technical specialist !

    M. Darrel Henderson - Semi-Retired Roofing Guru ! M. Henderson is a specialized Roofing Specialist, technical resource in regards to FMRC, UL and the NBC and many more involvment of the industry.

    He's the initiator of the URl lists for roofing since 1999

    It's with honnor that we can share those lists for you !






    Category : News

  • Horace presentation for O-RAS

    Posted on Jun 19, 2022

    Let me introduce myself, my name is Horace. I’ll be present from time to time on this platform to give you tips, tricks, advice and procedures to put forward in your project to allow you to determine, in this jungle that is the roofing industry, the right assembly to choose according to your needs and this… in complete neutrality.

    My presence and my name in your landscape come without a doubt from the derivative of the search engine O-RAS (Roof Assembly search for our English-speaking acolytes) and (Recherche d’Assemblages de Système …de toiture… chuut! For our French-speaking acolytes)

    As you know, the world of roofing is constantly changing and one of the latest requirements of the Canadian Building Code 2015 edition setting the wind uplift standard based on constant research by the NRC and of the SIGDERS group (Special Interest Group on Dynamic Evaluation of Roofing Systems) bringing together a large majority of industry stakeholders, all working to achieve stability and a standard on roofing application methods according to satisfactory criteria for everyone.

    In this sense, the web search engine for CSA A123.21, O-RAS test results is at your disposal! It is available at the site http://crt-csa.ca/fr/assembly-search

    Well, well, I hear you telling me that you are used to seeing the results via the manufacturer, or elsewhere, but here I am providing you with a summary as of today, which shows you that O-RAS is the only tool incorporating the largest number of test results in accordance with the CSA A123.21 standard. Table 1, constantly evolving, gives you a portrait of the advantages.


    Tableau reference 22-06-19.jpg

    Some sites list the test results according to the results obtained in the laboratory before reducing the safety factor of 1.5, others report results according to FM-4470 tests or do not include the types of anchors and their resistances. In addition, some tests are performed on steel decks of different gauges (either 33 or 40 ksi), which gives a distorted reference, if we do not pay specific attention to it!

    Follow me regularly at www.crt-csa.ca/blog, I will write articles on some of these particular points in order to allow you to stay on the road!

    New easy way to find the right roofing system for your particular roof according to the specifications of the National Building Code of Canada 2015 and this, in complete neutrality!

    Come and see often, some new systems will be updated gradually, if you are not sure how to use it or if you are looking for something special not listed here, join us on ; info@crt-csa.ca

    See you for the next article

    Category : Blog

  • The CSA A123.21 standard and roofing renovation

    Posted on Oct 04, 2018

    Comment utilise-t-on la norme CSA A123.21 pour la rénovation d’une toiture à faible pente? Comme mentionné dans des articles précédents abordant la légalisation, la spécification et l’application de la norme CSA A123.21, il est essentiel de connaître les contraintes et les limites de la norme afin de bien l’utiliser.

    Ce que nous disent les « commerciaux »

    La majorité des intervenants de l’industrie de la toiture s’entendent pour reconnaitre la norme de résistance au vent CSA A123.21 comme étant la référence de base au Canada pour les nouveaux projets de toiture. Pour les projets de rénovation qu’il soit sous forme de réfection partielle ou de recouvrement de surface, la situation n’est plus la même. L’assemblage existant doit être pris en compte.

    Or, comme la norme est relativement récente, plusieurs fabricants y voient une source intéressante de commercialisation pour leurs assemblages. En mentionnant certaines données incomplètes relativement à l’application des méthodes d’assemblages, ils mystifient les décideurs. Plusieurs font même mention que les résultats d’assemblages peuvent être appliqués sur tout type de toiture et de substrats, quels qu’ils soient.

    Que devrait-on y comprendre ?

    Afin de bien comprendre les tenants et aboutissants de la norme, vous devez savoir qu’il existe trois types d’assemblages qui se nomment : MARS, PARS et AARS.

    L’assemblage MARS

    MARS est l’acronyme de « Mecanicaly Attached Roofing System » qui est traduit par « Système de toiture en attache mécanique ». Cet assemblage implique que la membrane est attachée mécaniquement suivant les recommandations des systèmes testés par les manufacturiers.

    L’assemblage PARS

    PARS est l’acronyme de « Partly Adhered Roofing System » qui se traduit par « Système de toiture partiellement adhéré ». Ce type d’assemblage implique que certains éléments de l’assemblage sont attachés mécaniquement et que les autres le sont en pleine adhérence.

    L’assemblage AARS

    AARS est l’acronyme pour « Adhesive Adhered Roofing System » qui est traduit par « Système de toiture adhéré à l’adhésif ». Cet assemblage implique que tous les éléments de l’assemblage sont attachés les uns aux autres par cordons d’adhésif ou en pleine adhérence.

    Pour chacun de ces assemblages, les forces appliquées aux divers éléments sont différentes. Elles sont soit sous effet structural ou pneumatique soit un mélange des deux comme démontré à la page 22 de la norme CSA A123.21. Voir l’image ci-dessous.

    Comment intégrer la norme CSA A123.21 à votre projet

    Pour une nouvelle conception de toiture, aucune contrainte sur l’application de la norme ne se présente de façon notable. Cependant pour les travaux de remplacement de toiture complète ou partielle quelques éléments doivent être pris en compte afin de répondre aux exigences du Code national du bâtiment du Canada, édition 2015.

    Dans un premier temps, vous devez savoir si votre immeuble est assuré ou non par FM Global. Dans le cas où il ne l’est pas, la norme CSA A123.21 doit être appliquée en tenant compte des différents éléments et contraintes de chaque secteur de la toiture touché par les travaux de réfection.

    Des résultats de laboratoire

    Tous les manufacturiers effectuent des tests de résistance de leurs assemblages en laboratoire. Des pontages d’acier de béton ou de bois neufs avec des grades spécifiques possédant leurs propres propriétés de résistance sont utilisés pour réaliser ces tests. Les résultats obtenus forment les données de base.

    Chaque projet se doit de rencontrer ces données de base, principalement lorsque des attaches mécaniques sont utilisées. Par exemple, si un système a obtenu un résultat X avec une résistance d’ancrage de 300 lb lors de l’essai en laboratoire, le professionnel doit s’assurer de connaître la résistance des ancrages spécifiée au devis en fonction d’obtenir cette résistance de 300 lb au minimum sur le terrain.

    Ainsi, les méthodes MARS et PARS peuvent très bien répondre à la norme d’arrachement au vent CSA A123.21, à la condition de connaître en premier lieu les charges et les résistances à rencontrer. Pour ce faire, des essais « In Situ » normalisés devraient être effectués lors des coupes de validation des systèmes en place. Ces essais normalisés sont pour les ancrages ANSI/SPRI FX-1 et pour les cas de réfections en adhérence la norme ANSI/SPRI IA-1 peut permettre d’obtenir les informations de base nécessaires à l’application d’un système AARS.

    Centrale de référence de toiture

    Indépendante et neutre, la Centrale de référence de toiture vous informe sur les divers aspects de la norme CSA A123.21 et de son application pour vos projets de toiture. Pour de plus amples informations, communiquez avec nous.

    Michel Desgranges, T.P.

    Category : Blog

  • Is the white roof really effective?

    Posted on Aug 17, 2018

    The white roof is one of the latest trends in energy efficiency. Its installation is equally present in the residential, commercial, industrial and institutional sectors, both in the United States and in Canada. Over the last 15 years, white or reflective roofs have become very popular. They are even part of the prescriptive requirements in some northern cities like Montreal.

    It is true that in some warmer climates, the white roof is a useful and effective option. But its systematic use in cities north of the 45th parallel raises a great deal of questioning and requires, in my opinion, a careful examination of each project before continuing the trend of reflective roofs.

    The myth of white roofs

    The popular favor as well as many regulations, not scientifically based, tell us that white roofs always save energy and reduce pollution. Unfortunately, this statement is a myth!

    The claimed benefits of reflective roofs, especially when used in colder climates, are based on unclear science and selfish marketing that has led to the belief that white roofs are energy efficient and more cost effective than more conventional roofs.

    What is it really?

    In fact, white roof membranes have a high reflectivity that directs heat upward, as do energy-efficient glasses. Therefore, the presence of a vapor barrier on the hot side of an assembly, which is mandatory according to the Building Code, traps an abnormal rate of condensation under the white membrane which, in turn, has weak properties. permeability to water vapor.

    Result: Extreme condensation problem, water infiltration, breakdown of ventilated wood decks and much more!

    And who will be responsible for these problematic situations? Considering that the contractor installs the white membranes by obligation in the sectors identified by the Régie municipale and the regulations in force without being able to take into account the type of construction of the building and its environment, can it be held responsible for the problems which result?

    Reduction of heat islands: Bilateral consequences

    In an urgency to reduce "the effect of heat islands" by a few degrees in summer, white roofs have been presented as "a saving solution to counteract global warming. In Nordic countries like Canada, this notion remains true for a few weeks a year, 6 weeks at most!

    This same phenomenon is considerably reversed in winter, where snow accumulated on the surface acts as an additional insulator, displacing the dew point under the membrane. Not to mention accumulated dirt that significantly reduces the rate of reflection, and this, from the second year after installation.

    What the studies say

    All studies, including the Lawrence Berkeley National Laboratory, demonstrate the effectiveness of reflective white roofing throughout, including northern climates. However, these studies do not take into account thermal performance, air infiltration or steam entrainment. They are limited to measuring the surface temperature at the roof level.

    New studies, including one from Virginia Tech, question the energy savings of white reflective membranes and challenge the hypothesis on which standards and codes were based. They demonstrate that the reflectivity of windows, masonry walls, ventilated roofs and many other phenomena contributes more to the increase of the ambient temperature and can even cancel and cause problems of condensations or others.


    Architects, engineers, building owners and roof system designers are also questioning their scientific validity. In a PDF document available on their website, RCI recognizes that for colder climates installing a reflective roof is not always the ideal option.


    Thermal image showing condensation contamination of a wood decking after only 2 years of installation.

    My expertise, my questioning

    Working as a building envelope waterproofing consultant with specialization in infrared thermography and having no connection with any membrane manufacturer, I consider that I have an unbiased perspective and expertise supported by sad realities.

    Considering now the various problems related to the white roof in northern climate, a question arises: should one wait for major roof subsidence before reconsidering the systematic implementation of white roof on a building?

    Sources :

    Michel Desgranges, T.P.

    OTPQ : 18788

    Category : Blog

  • Roofing projects coming !

    Posted on Jan 02, 2018

    Looking for a normative information platform in roofing domain?

    To meet the demands of manufacturers with upcoming projects across Canada, their possibilities to conduct tests in different laboratories recognized in Canada and the United States. It is essential to be able to obtain, quickly and accurately, an assembly meeting the specific requirements of each roofing projects in a neutral and centralized in one place.

    Few questions ask by the industry ?

    Central Roof Reference !

    Q : How to benefit Canadians fairly our CSA A123.21 test results? R : By a centralized approach via a search engine on a website mainly dedicated taking into account the values obtained by the online calculator Wind-Rci.

    Q : A centralized website accessible for that and for who? R : It is accessible to the public, for validation purposes by architects, specifiers, contractors, manufacturers, managers, etc.

    Q : How will it work? R : The first step will be to get the resistance to project’s assess, the values serve as a basis in the search engine, subsequently, the desired type of system, the type of adhesion/attachment and/or manufacturers, to finally get a short list of possible assemblies.

    ONE PLACE TO FIND IT ALL Stop searching all over the web or in manufacturing, all will be at the same place.

    For any assistance ! Contact us info@crt-csa.ca

    Category : Blog

  • Why using CSA-A123.21 standard?

    Posted on Sep 15, 2017

    CSA A123.21 standard protect you, as it meets the requirements of the specific elements in force in the National Building Code of Canada 2015 (NBCC) and earlier.

    Using an assembly tested according to the CSA-A123.21 specifications and designed for the building you are working on, you ensure that you are in good standing with the NBCC and that the chosen system will respond effectively to the elements according to the specific criteria of your project such as:

    • Building location
    • Building geometry
    • Building exposure
    • Building openings
    • Importance category (risk level)

    So, with accurate results for your project and using the right materials with the right linked fixing method to each other, your risk level is greatly reduced.

    CSA A123.21 Standard: his reason of being

    It is important to note that since 2004 an interest group formed by researchers from the National Research Council of Canada (NRC) and involving most stakeholders in the roofing industry in North America exists. This group, SIGDERS (Special Interest Group on the Dynamic Evaluation of Roofing Systems), has developed a dynamic test protocol simulating actual and real cyclic and variable wind pressures.

    Previously, designers had to use either their previous experiences or use empirical data available from manufacturers

    The basis for these data was the requirements of an American insurance company known as the Global FM and their laboratory Factory Mutual (FM). Those data, better known as FM 1-90 or other and used by most Canadian professionals, represent the resistance to a static lifting pressure of 90 psi.

    This practice was deemed insufficient, and the requirement for a dynamic calculation came into being in section 4.1.7 in 2005, thus provoking the urgency of designing a protocol dedicated to it. To counter this, dynamic calculation methods have been included in the Canadian Building Code in the user guide section and adjusted as the CSAS A123.21.

    CSA A123.21 Standard: Its scope

    This test method determines the pull-out resistance of wind-driven membrane roofing systems when subjected to dynamic wind load cycles.

    The test methods are applicable to mechanically fastened or adherent membrane roof systems.

    The roofing system comprises a bridging and a roofing membrane. It also includes components such as vapor barrier, thermal barriers or retarders, insulation, cover panel, etc. It is subjected to a dynamic load sequence that has been developed as a function of wind pressure records simulating the effects of wind on the membrane roof assembly.

    Now that CSA A123.21 has become law in some Canadian provinces, many different interpretations are being conveyed for commercializing waterproof systems by different laboratories and manufacturers.

    It is therefore essential to know the details of this new standard and to be able to use it adequately. To do so, should not hesitate to inquire about the test methods used, and to validate the relevance of the elements included in the documents presented. In addition, ensure that the laboratory is recognized by NRC and accredited to ISO-17025 for this type of test.

    Central Roof Reference: all about the CSA A123.21 standard

    Central Roof Reference is your reference portal for CSA A123.21 for the design and construction of Canadian roofs. Use our tool to determine which roofing assembly is right for your construction project.

    Any questions? Contact us!

    Category : Blog

  • Central Roof Reference and Wind Uplift CSA A123.21

    Posted on Mar 09, 2017

    We're now part of the Construction Standard list

    Your place to find tested roof assemblies

    Central Roof Reference is now part of the list of important sites in the North American building envelope weatherproofing industry. This list is, updated annually by Mr. Darrel Henderson Esq. From Rooftech Services, he’s a recognized member of the RCI Chapter Ontario, emitted with more than 250 copies of Ontario chapter members.

    Central Roof Reference is the central site for published results of the roofing system assemblies tested per the nomenclature of CSA A123.21 standards and coming from any recognized North-American laboratories.

    Proud to be part of this section dealing with the bundling of web links; Construction standards, Laws, codes and regulations, and this, among the most important ones! Here is an excerpt from the main document;

    Central Roof reference gives you the opportunity to be seen all over Canada, and most of all, being redirect to your website on many ways! So be present…

    Category : Blog

  • Application of the standard CSA A123.21 for your projects

    Posted on Mar 22, 2016

    Now that the standard has become bi-law in some Canadian provinces, and that many different interpretations are conveyed for the purpose of commercialization of waterproofing systems.
    It is essential to be able to obtain, quickly and accurately, an assembly meeting the specific requirements of each roofing projects with neutrality and integrity.


    Adapted normative advisory service

    With over 30 years experience in the building envelope weathertighness with a specialization of over 20 years in roofing waterproofing, it’s possible to address your special normative requests and information.

    Having participated for several years in the development, improvement and integration of CSA A123.21 standards in the National Building Code of Canada 2015 with the SIGDERS grouping created by NRC, voting member associations; ASTM International (D-08 Committee, C-24 and E06), CSA Group committee Roofing and waterproofing, RCI envelope weatertighness Technical Committee.

    Whether you are architects, specifiers, contractors, manufacturers, managers,etc. you will get the most appropriate information services to your project.


    Stop searching all over the web or in manufacturing, all will be at the same place, send requests with our contact form


    Category : Blog

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