A. H. RAHMAN Institute for Research in Construction, N.R.C.
and PROFESSOR G. T. SUTER Carleton University, Ottawa
Thermal movements have all too frequently ted to distress in masonry envelopes of buildings. This paper deals with a thermal analysis to determine the extreme temperatures in the exterior wall and the corresponding temperature distributions in an intersecting interior wall of a building of loadbearing masonry wall construction. Due to the variation of solar radiation and other environmental factors as well as the high thermal mass of masonry, heat flow across masonry walls is far from a steady state condition. A transient one-dimensional heat flow analysis using the climatic data of the Ottawa region was carried out to determine the extreme temperatures in the exterior wall. All climatological factors were considered together with data on such factors and material properties as available in the literature supplemented by studies of those parameters whose influences were not clearly known. Comparison of the results of this transient analysis to those of a steady state analysis shows that the latter significantly overestimates the maximum summertime temperatures in the exterior wall. A steady state analysis was deemed accurate enough to determine the temperature distributions in the interior crosswall corresponding to the maximum and minimum temperatures in the exterior wall.