Dr. Michael A. Lacasse is a senior research officer in the Construction Research Center of the National Research Council Canada (NRC-CRC) having over 33 years experience as a building engineer. His current role within the NRC-CRC is Team Leader for the Facades Systems and Products Team. Since joining NRC in 1991, he has been active in various ISO, ASTM, CSA, and CIB technical committees related to performance of envelope and the durability and service-life prediction of materials and components. He chairs the ISO technical committee for TC59 SC14, "Design Life of Buildings" and is an active member and current coordinator (1997-2005 / 2017- ) to the activities of the CIB technical committee W080 "Prediction of Service Life of Building Materials and Components”. As well, he participates in ASTM activities of committee E06 on “Performance of Buildings”. More recently he has been asked to support the work of the NBC Part 5 “Building enclosures” and is a current member of the committee to develop the CSA S478 “Guideline on Durability in Buildings”. Dr. Lacasse prior to working at the NRC worked both in private industry and government construction agencies. Phone: +1 343 550 4260 Address: National Research Council Canada Construction Research Centre 1200 Montreal Road, Building M24 Ottawa, Ontario, K1A 0R6 Canada
IOP Conference Series: Earth and Environmental Science
Facade failures due to rainwater entry are common in Turkey although, few systematic studies have... more Facade failures due to rainwater entry are common in Turkey although, few systematic studies have been completed to determine the types of defects and failures and their causes as would permit developing appropriate repair solutions. The intent of this study is to determine the types of defects and failures caused by rainwater ingress to building facades based on case studies of failure in Turkey. Thus, defects and failures can be characterized and classified, such that the most common types of failure can be revealed and adequate repair solutions proposed. A review of literature was conducted of studies undertaken in Turkey on rainwater entry and building defects. Additionally, field inspections were carried out for 16 public buildings in Istanbul and information regarding failures was gathered from local authorities. Based on data evaluated from previous research and field inspections, it was determined that majority of the buildings had cladding walls with stucco being the most c...
This report has been compiled based on experimental work carried out in the laboratories of theIn... more This report has been compiled based on experimental work carried out in the laboratories of theInstitute for Research in Construction, a review of pertinent literature and feedback obtained fromdifferent experts and practitioners of window installation. It forms the initial part (Phase 1) of aseries of three reports prepared on the 'Performance Evaluation of Wall-Window InterfaceDetails'. Of the eight chapters provided in this report, the first three provide an introduction to thework in which the approach to the performance assessment process is described, the developmentand rationale for the test method are given, and a summary description of the test specimens isoffered.
Wind-driven rain (WDR) is the main moisture source that affects the hygrothermal performance and ... more Wind-driven rain (WDR) is the main moisture source that affects the hygrothermal performance and durability of building envelopes. Therefore, the quantity of wind-driven rain impinging on the surface of buildings' façade constitutes an important consideration for the design of the building envelopes. Three semi-empirical models are available in the literature to estimate the quantity of wind-driven rain that impinges on the cladding surface, namely ASHRAE model, ISO model, and the Straube and Burnett model (thereafter called SB model). The objective of this work was to compare the consistency of hygrothermal responses and moisture performances of wood-frame wall assemblies as predicted by hygrothermal simulations with WDR calculated using these three models. These models were computed and compared for a Terrain Category III, corresponding to a suburban area as described in the ISO Standard. This comparative study was carried out for four different wood-frame wall systems differi...
Abstract Air-barrier systems (ABSs) are essential elements in the performance of building envelop... more Abstract Air-barrier systems (ABSs) are essential elements in the performance of building envelopes and they are specified in the National Building Code of Canada (NBC) to minimize the infiltration...
L'installation efficace et durable des fenêtres demande une bonne étanchéité à l'air et u... more L'installation efficace et durable des fenêtres demande une bonne étanchéité à l'air et une bonne gestion de l'eau. Dans ce numéro, on explique le rôle joué par le degré d'étanchéité à l'air et l'emplacement du plan d'étanchéité à l'air de l'interface mur-fenêtre dans les infiltrations d'eau de pluie. C'est le deuxième numéro d'une série de Solutions constructives sur les détails d'installation des fenêtres.
Pour une bonne performance des fenêtres, il faut un bon produit et une installation appropriée. L... more Pour une bonne performance des fenêtres, il faut un bon produit et une installation appropriée. La présente Solution constructive présente les résultats d'une étude récente des détails d'installation des appuis de fenêtre en vue d'un drainage efficace des infiltrations d'eau aux interfaces mur-fenêtre.
An effective and durable window installation demands good airtightness and proper water managemen... more An effective and durable window installation demands good airtightness and proper water management. This Update explains how the degree of airtightness and the location of the plane of airtightness of the wall-window interface affect water entry. It is the second in a series of Updates presenting results from studies of window installation details.
Satisfactory window performance demands a good product and proper installation. This Update prese... more Satisfactory window performance demands a good product and proper installation. This Update presents results from a recent study of sill installation details for the effective drainage of inadvertent water entry at the wall-window interface.
Water penetration in the wall assembly through deficiencies, resulting from the coupled action of... more Water penetration in the wall assembly through deficiencies, resulting from the coupled action of rain and wind, also known as wind-driven rain (WDR), can cause degradation of tall wood building components (e.g. mould growth, wood decay), thereby by reducing their performance and service life. Three semi-empirical models are available in the literature to estimate the quantity of wind-driven rain that impinges on the cladding surface: the ASHRAE model, the ISO model, and the Straube and Burnett model (SB model). The objective of this work was to compare the consistency of the hygrothermal responses and the moisture performance of the CLT panel used in massive timber walls as predicted by hygrothermal simulations with WDR calculated using the three models. Three Canadian cities having contrasting climates were selected for simulation: Vancouver (BC) located in Climate Zone 5 with a minimum RSI-value requirement of 3.60; Ottawa (ON) located in Climate Zone 6 with a minimum RSI-value r...
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, co... more Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team at PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRC
The main emphasis of the MEWS project was to predict the hygrothermal responses of several wall a... more The main emphasis of the MEWS project was to predict the hygrothermal responses of several wall assemblies that are exposed to North American climate loads, and a range of water leakage loads. Researchers used a method based on both laboratory experimentation and 2-D modeling with IRC's benchmarked model, hygIRC. This method introduced built-in detailing deficiencies that allowed water leakage into the stud cavity-both in the laboratory test specimens and in the virtual (modeling) " specimens "-for the purpose of investigating water entry rates into the stud cavity and the drying potential of the wall assemblies under different climate loads. Since the project was a first step in investigating a range of wall hygrothermal responses in a parametric analysis, no field study of building characteristics was performed to confirm inputs such as water entry rates and outputs such as wall response in a given climate. Rather, ranges from 'no water entry and no response'...
stock. The reasons for the difficulties relate directly to the lack of usable data, information a... more stock. The reasons for the difficulties relate directly to the lack of usable data, information and knowledge related to service life prediction, and the lack of tools to assist the asset manager in making a proper repair choice. The Building Envelope Life Cycle Asset Management (BELCAM) project addresses these two deficiencies: its goal is to develop methods to predict the service life of the building envelope and its elements, and to assist asset managers in maintaining these building components. The project in the initial stages focuses on roofing, and seeks to integrate existing enabling technologies used in this domain, namely: maintenance management, life cycle economics, service life prediction, user requirement modeling, risk analysis, and product modeling. Although there exists degradation models for flat roof systems, as well as a number of roofing maintenance management packages, these have yet to be integrated into a consistent resource that satisfies the asset manager&a...
This paper presents further steps in the development of reliability-based approaches for the dura... more This paper presents further steps in the development of reliability-based approaches for the durability design and service life prediction of building components which integrate the requirements of safety, serviceability and durability. In general, the load and resistance should be modelled as stochastic processes and the resulting durability problem is formulated in a time-dependent probabilistic format. Using the classical reliability approach, the resulting time-dependent reliability problem is transformed into a time-independent reliability problem through the adoption of an extreme-value probability distribution for the maximum lifetime load. The resistance degradation and its variability are included in the model, and the probabilistic design problem is transformed into a deterministic (or semi-probabilistic) problem using the first-order second moment theory. This semi-probabilistic integrated approach to durability design and prediction overcomes the shortcomings of the empi...
This paper presents the framework of a stochastic decision-support system for life cycle asset ma... more This paper presents the framework of a stochastic decision-support system for life cycle asset maintenance management of building elements and systems. This system is based on a probabilistic modeling of the performance and risk of failure of building components. The maintenance optimization is formulated as a multi-stage and multiobjective optimization problem where the simultaneous satisfaction of several conflicting objectives, including minimization of maintenance costs, maximization of performance, and minimization of risk of failure, is sought. Compromise programming is used to determine the optimal ranking of the deteriorated components in terms of their priority for repair and replacement, by achieving a satisfactory trade-off between the competing or conflicting objectives. A product model of the building system is used to provide the data framework for collecting and processing data.
IOP Conference Series: Earth and Environmental Science
Facade failures due to rainwater entry are common in Turkey although, few systematic studies have... more Facade failures due to rainwater entry are common in Turkey although, few systematic studies have been completed to determine the types of defects and failures and their causes as would permit developing appropriate repair solutions. The intent of this study is to determine the types of defects and failures caused by rainwater ingress to building facades based on case studies of failure in Turkey. Thus, defects and failures can be characterized and classified, such that the most common types of failure can be revealed and adequate repair solutions proposed. A review of literature was conducted of studies undertaken in Turkey on rainwater entry and building defects. Additionally, field inspections were carried out for 16 public buildings in Istanbul and information regarding failures was gathered from local authorities. Based on data evaluated from previous research and field inspections, it was determined that majority of the buildings had cladding walls with stucco being the most c...
This report has been compiled based on experimental work carried out in the laboratories of theIn... more This report has been compiled based on experimental work carried out in the laboratories of theInstitute for Research in Construction, a review of pertinent literature and feedback obtained fromdifferent experts and practitioners of window installation. It forms the initial part (Phase 1) of aseries of three reports prepared on the 'Performance Evaluation of Wall-Window InterfaceDetails'. Of the eight chapters provided in this report, the first three provide an introduction to thework in which the approach to the performance assessment process is described, the developmentand rationale for the test method are given, and a summary description of the test specimens isoffered.
Wind-driven rain (WDR) is the main moisture source that affects the hygrothermal performance and ... more Wind-driven rain (WDR) is the main moisture source that affects the hygrothermal performance and durability of building envelopes. Therefore, the quantity of wind-driven rain impinging on the surface of buildings' façade constitutes an important consideration for the design of the building envelopes. Three semi-empirical models are available in the literature to estimate the quantity of wind-driven rain that impinges on the cladding surface, namely ASHRAE model, ISO model, and the Straube and Burnett model (thereafter called SB model). The objective of this work was to compare the consistency of hygrothermal responses and moisture performances of wood-frame wall assemblies as predicted by hygrothermal simulations with WDR calculated using these three models. These models were computed and compared for a Terrain Category III, corresponding to a suburban area as described in the ISO Standard. This comparative study was carried out for four different wood-frame wall systems differi...
Abstract Air-barrier systems (ABSs) are essential elements in the performance of building envelop... more Abstract Air-barrier systems (ABSs) are essential elements in the performance of building envelopes and they are specified in the National Building Code of Canada (NBC) to minimize the infiltration...
L'installation efficace et durable des fenêtres demande une bonne étanchéité à l'air et u... more L'installation efficace et durable des fenêtres demande une bonne étanchéité à l'air et une bonne gestion de l'eau. Dans ce numéro, on explique le rôle joué par le degré d'étanchéité à l'air et l'emplacement du plan d'étanchéité à l'air de l'interface mur-fenêtre dans les infiltrations d'eau de pluie. C'est le deuxième numéro d'une série de Solutions constructives sur les détails d'installation des fenêtres.
Pour une bonne performance des fenêtres, il faut un bon produit et une installation appropriée. L... more Pour une bonne performance des fenêtres, il faut un bon produit et une installation appropriée. La présente Solution constructive présente les résultats d'une étude récente des détails d'installation des appuis de fenêtre en vue d'un drainage efficace des infiltrations d'eau aux interfaces mur-fenêtre.
An effective and durable window installation demands good airtightness and proper water managemen... more An effective and durable window installation demands good airtightness and proper water management. This Update explains how the degree of airtightness and the location of the plane of airtightness of the wall-window interface affect water entry. It is the second in a series of Updates presenting results from studies of window installation details.
Satisfactory window performance demands a good product and proper installation. This Update prese... more Satisfactory window performance demands a good product and proper installation. This Update presents results from a recent study of sill installation details for the effective drainage of inadvertent water entry at the wall-window interface.
Water penetration in the wall assembly through deficiencies, resulting from the coupled action of... more Water penetration in the wall assembly through deficiencies, resulting from the coupled action of rain and wind, also known as wind-driven rain (WDR), can cause degradation of tall wood building components (e.g. mould growth, wood decay), thereby by reducing their performance and service life. Three semi-empirical models are available in the literature to estimate the quantity of wind-driven rain that impinges on the cladding surface: the ASHRAE model, the ISO model, and the Straube and Burnett model (SB model). The objective of this work was to compare the consistency of the hygrothermal responses and the moisture performance of the CLT panel used in massive timber walls as predicted by hygrothermal simulations with WDR calculated using the three models. Three Canadian cities having contrasting climates were selected for simulation: Vancouver (BC) located in Climate Zone 5 with a minimum RSI-value requirement of 3.60; Ottawa (ON) located in Climate Zone 6 with a minimum RSI-value r...
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, co... more Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team at PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRC
The main emphasis of the MEWS project was to predict the hygrothermal responses of several wall a... more The main emphasis of the MEWS project was to predict the hygrothermal responses of several wall assemblies that are exposed to North American climate loads, and a range of water leakage loads. Researchers used a method based on both laboratory experimentation and 2-D modeling with IRC's benchmarked model, hygIRC. This method introduced built-in detailing deficiencies that allowed water leakage into the stud cavity-both in the laboratory test specimens and in the virtual (modeling) " specimens "-for the purpose of investigating water entry rates into the stud cavity and the drying potential of the wall assemblies under different climate loads. Since the project was a first step in investigating a range of wall hygrothermal responses in a parametric analysis, no field study of building characteristics was performed to confirm inputs such as water entry rates and outputs such as wall response in a given climate. Rather, ranges from 'no water entry and no response'...
stock. The reasons for the difficulties relate directly to the lack of usable data, information a... more stock. The reasons for the difficulties relate directly to the lack of usable data, information and knowledge related to service life prediction, and the lack of tools to assist the asset manager in making a proper repair choice. The Building Envelope Life Cycle Asset Management (BELCAM) project addresses these two deficiencies: its goal is to develop methods to predict the service life of the building envelope and its elements, and to assist asset managers in maintaining these building components. The project in the initial stages focuses on roofing, and seeks to integrate existing enabling technologies used in this domain, namely: maintenance management, life cycle economics, service life prediction, user requirement modeling, risk analysis, and product modeling. Although there exists degradation models for flat roof systems, as well as a number of roofing maintenance management packages, these have yet to be integrated into a consistent resource that satisfies the asset manager&a...
This paper presents further steps in the development of reliability-based approaches for the dura... more This paper presents further steps in the development of reliability-based approaches for the durability design and service life prediction of building components which integrate the requirements of safety, serviceability and durability. In general, the load and resistance should be modelled as stochastic processes and the resulting durability problem is formulated in a time-dependent probabilistic format. Using the classical reliability approach, the resulting time-dependent reliability problem is transformed into a time-independent reliability problem through the adoption of an extreme-value probability distribution for the maximum lifetime load. The resistance degradation and its variability are included in the model, and the probabilistic design problem is transformed into a deterministic (or semi-probabilistic) problem using the first-order second moment theory. This semi-probabilistic integrated approach to durability design and prediction overcomes the shortcomings of the empi...
This paper presents the framework of a stochastic decision-support system for life cycle asset ma... more This paper presents the framework of a stochastic decision-support system for life cycle asset maintenance management of building elements and systems. This system is based on a probabilistic modeling of the performance and risk of failure of building components. The maintenance optimization is formulated as a multi-stage and multiobjective optimization problem where the simultaneous satisfaction of several conflicting objectives, including minimization of maintenance costs, maximization of performance, and minimization of risk of failure, is sought. Compromise programming is used to determine the optimal ranking of the deteriorated components in terms of their priority for repair and replacement, by achieving a satisfactory trade-off between the competing or conflicting objectives. A product model of the building system is used to provide the data framework for collecting and processing data.
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Papers by Michael A Lacasse