- Author
-
Fishburn, C. C.
|
Petersen, P. H.
- Title
- Effect of Heating and Cooling on the Permeability of Masonry Walls.
- Coporate
- National Bureau of Standards, Washington, DC
- Report
-
BMS 41,
January 11, 1940,
8 p.
- Keywords
-
walls
|
masonry
|
heating
|
cooling
|
permeability
|
clay
- Abstract
- Since the coefficients of thermal expansion of masonry units and mortars are unequal, changes in temperature may tend to cause cracks in the mortar joints of masonry walls. Exposure to wind-driven rain may then result in the leakage of water through the walls. Permeability tests wer made on 11 small masonry wall specimens before and after exposing them to a number of cycles of heating and cooling. Seven of the specimens were 12-in. brick walls, two were of clay tile with stucco facings, and two were brick walls with hollow-unity backings. The walls were dry when subjected to extremes of temperature over a range of about 105 det F. The maximum air temperature was about 125 deg F and the minimum less than 20 deg F. For each cycle, the walls were stored in the heating or cooling rooms until they attained room temperature. Data obtained from the tests indicated that repeated exposures of dry walls to extremes of temperature did not have an important effect on the permeability of all-brick walls. The permeabilities of the walls with facings of brick and backings of hollow units and of those faced with stucco increased slightly as the result of exposure to cycles of heating and cooling