Form Approved
REPORT DOCUMENTATION PAGE
OMB No. 0704-0188
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1. AGENCY USE ONLY (Leave blank)
2. REPORT DATE
3. REPORT TYPE AND DATES COVERED
July 1995
4. TITLE AND SUBTITLE
5. FUNDING NUMBERS
Roof Blisters: Cause and Cure
6. AUTHORS
Charles Korhonen and Brian Charest
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)
8. PERFORMING ORGANIZATION
REPORT NUMBER
U.S. Army Cold Regions Research and Engineering Laboratory
72 Lyme Road
Special Report 95-19
Hanover, New Hampshire 03755-1290
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)
10. SPONSORING/MONITORING
AGENCY REPORT NUMBER
Office of the Chief of Engineers
Washington, D.C. 20314-1000
11. SUPPLEMENTARY NOTES
For conversion of SI units to non-SI units of measurement consult Standard Practice for Use of the International System of Units (SI),
ASTM Standard E380-93, published by the American Society for Testing and Materials, 1916 Race St., Philadelphia, Pa. 19103.
12a. DISTRIBUTION/AVAILABILITY STATEMENT
12b. DISTRIBUTION CODE
Approved for public release; distribution is unlimited.
Available from NTIS, Springfield, Virginia 22161.
13. ABSTRACT (Maximum 200 words)
Blisters are a major problem of built-up roof membranes. They are caused by voids built into the roof during
construction. They develop into the characteristic dome-shaped humps by a breathing action driven by ther-
mal cycling. A small pressure relief vent was patented by CRREL as a cost-effective way to repair blisters.
Though these vents cannot prevent blisters from forming, they can lengthen a roof's service life by repairing
the blisters before they break. Two demonstration projects were conducted to transfer the blister vent tech-
nology to the military community. Most participants in the demonstration projects found the vent easy to
use and that it performed as designed. The main objection to the vent was its price.
14. SUBJECT TERMS
15. NUMBER OF PAGES
13
Blister
Maintenance
16. PRICE CODE
Built-up roof
Repair
17. SECURITY CLASSIFICATION
18. SECURITY CLASSIFICATION
19. SECURITY CLASSIFICATION
20. LIMITATION OF ABSTRACT
OF REPORT
OF THIS PAGE
OF ABSTRACT
UNCLASSIFIED
UNCLASSIFIED
UNCLASSIFIED
UL
Standard Form 298 (Rev. 2-89)
NSN 7540-01-280-5500
Prescribed by ANSI Std. Z39-18
298-102
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