CLOQUET RESIDENTIAL RESEARCH FACILITY:
WALL SYSTEMS HYGROTHERMAL PERFORMANCE EXPERIMENTAL EVALUATION
June 2007 – January 2009

Principal Investigator: Louise F. Goldberg Ph.D (Eng)
Energy Systems Design Program
College of Design
Co-Principal Investigator: Patrick H. Huelman
Cold Climate Housing Program
Department of Bioproducts/Biosystems Engineering
Research Associate: Robert Seavey Ph.D
Department of Bioproducts/Biosystems Engineering
Technician: Charles Kramer
Cloquet Forestry Center
Sponsors: CertainTeed Corporation
Stanley D. Gatland II
  Minnesota Lath and Plaster Bureau
Steven Pedracine
Contributors: Brian Peterson Stucco, Inc
  Mark Stender
Moisture Management, LLC

ACKNOWLEDGEMENTS AND DISCLAIMER

The research described herein has been performed with funding provided by the CertainTeed Corporation and the Minnesota Lath and Plaster Bureau with additional contributions by Brian Peterson Stucco, Inc. and Moisture Management, LLC. 

While this support is gratefully acknowledged, the Principal Investigators assume complete responsibility for the contents herein.



Energy
Systems Design Program
College of Design, University of Minnesota
1425 University Ave SE, Suite 220
Minneapolis, MN 55414

Release date
: June 19, 2009

SUMMARY

In order to compare the efficacy of 2-mil PA-6 and 4-mil PE as warm-side vapor retarders and to clarify the impacts of stucco cladding on wall system hygrothermal phenomenology, eleven different above-grade envelope wall systems were continuously tested for a period of 13.5 months at the University of Minnesota’s Cloquet Residential Research Facility.  Each system was tested simultaneously on both a north and a south wall exposure.  Experimental hygrothermal performance data including sensible and dew point temperatures, relative humidities and sheathing moisture contents were collected continuously over the duration of the experiment with a data reliability in excess of 99 %.  A detailed photographic record of the dismantling of the all the test sections at the end of the experiment was assembled and reported herein.

A universal building envelope hygrothermal performance standard is presented as an extension of the building foundation wall hygrothermal performance criterion currently promulgated in the Minnesota Building Code and the performance of the tested wall systems is evaluated in terms of this standard.

As expected, none of the tested systems complied with the universal standard because none of the systems was designed specifically to comply with it.  However, some of the systems tested did show that compliance with the standard is possible even for cavity insulated wall systems.  In general terms, the results show that 2-mil. polyamide-6 vapor retarders yield superior hygrothermal performance as determined by sheathing moisture content to conventional 4-mil. polyethylene vapor retarders in the absence of complicating vapor bypass phenomenology.  The negative consequences of vapor bypass effects at the edges of framing cavities in which the vapor retarder is not sealed to the framing were clearly demonstrated.  The experimental data do not provide any evidence that stucco cladding is inappropriate for use in a cold climate or that stucco systems by themselves are the cause of wall system biotic failures.

TABLE OF CONTENTS

A.       INTRODUCTION
B.
       UNIVERSAL BUILDING ENVELOPE HYGROTHERMAL PERFORMANCE STANDARD
C.
       WALL SYSTEMS TESTED
D.
       INSTRUMENTATION
E.
       BOUNDARY CONDITIONS
F.
       RESULTS
    F.1
      Section 1 – Sheathing Moisture Content
    F.2
      Section 2 – Cavity Relative Humidity
    F.3
      Section 3 – Detailed Hygrothermal Performance
G.
       TEST SYSTEM DISMANTLING
H.
       UNIVERSAL ENVELOPE HYGROTHERMAL PERFORMANCE STANDARD COMPLIANCE
I.
         CONCLUSIONS
J.
        REFERENCES

Download the full reportWalls-6_09-Final.pdf (133 pages, 41.4 Mbytes)

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Revision date: 6/19/09