A brief compendium of water entry results derived from laboratory tests of various types of wall assemblies

Michael A Lacasse,Nathan Van Den Bossche,Travis V Moore,Stephanie Van Linden,R Černý,V Kočí,J Kočí

doi:10.1051/matecconf/201928202050

Michael A Lacasse, Nathan Van Den Bossche + Show 5 more

Open Access

https://doi.org/10.1051/matecconf/201928202050

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Abstract

There is an increase in the use of hygrothermal models to complete the performance evaluation of walls assemblies, either in respect to design of new assembles or the retrofit of existing wall assemblies. To this end there are guides available in which is provided information on moisture loads to wall assemblies. This includes, for example, Criteria for Moisture-Control Design Analysis in Buildings given in ASHRAE 160, Assessment of moisture transfer by numerical simulation provided in EN 15026, and NRC’s “Guidelines for Design for Durability of the Building Envelope”. The designer of a new assembly or evaluator of an existing wall is tasked with having to determine what moisture loads to apply to the wall and where to apply this load within the assembly. Typically there is little or no information that is readily available regarding moisture loads to walls and thus the suggested hourly moisture load, as given in ASHRAE 160, is 1% by weight of the total driving rain load to the wall (i.e. kg/m2-hr). In this paper, a brief compendium of water entry test results derived from laboratory tests of various types of wall assemblies is provided from which estimates of moisture loads to different types of wall can be developed. Water entry test results are given of wood frame walls typically used in housing, but also metal-glass curtain walls and other commercial wall assemblies, where possible, in terms of driving loads to the wall.

Highlights

There is an increase in the use of heat air and moisture (HAM) transport models to complete the performance evaluation of wall assemblies, either in respect to design of new assembles or the retrofit of existing wall assemblies
To this end there are guides available which provide information on moisture loads to wall assemblies. This includes, for example, Criteria for Moisture-Control Design Analysis in Buildings given in ASHRAE 160 [2], Assessment of moisture transfer by numerical simulation provided in EN 15026 [3], and NRC’s “Guidelines for Design for Durability of the Building Envelope” [4]
Water infiltration has been recorded without any pressure difference over the wall assembly if openings or deficiencies were present at the exterior surface of the wall assemblies

Summary

Introduction

There is an increase in the use of heat air and moisture (HAM) transport models to complete the performance evaluation of wall assemblies, either in respect to design of new assembles or the retrofit of existing wall assemblies. There are numerous examples of the use of HAM models to assess the moisture performance of various types of wall assemblies, too many to cite here; fewer examples exist as relate to estimating the service life of wall assemblies To this end there are guides available which provide information on moisture loads to wall assemblies. More recent efforts include: Cornick & Lacasse [6], who provided information as relates to Canada and the US; Giarma and Aravantinos [7] for Greece; Pérez-Bella et al for Spain [8] and Chile [9]; DomínguezHernández et al for Brazil [7] and for the UK, Orr & Viles [11] These references provide methods by which the WDR load to the cladding can be assessed, given appropriate local climate data information. The proposed methods offer insight into how moisture loads on the exterior of the cladding can vary, and how to consider effects of runoff in hygrothermal simulations

Overview of water infiltration of wall assemblies

Findings

Moisture source for hygrothermal simulations