H. KELLER, P.ENG AND S. LAVIOLETTE, P.ENG.
The paper deals with the results of a 12-month monitoring program of massive sandstone masonry walls in a heritage structure in Ottawa. Measurements included temperature, moisture, relative humidity and pressure across the exterior wall system and windows. The purpose of this monitoring program was to determine the source of moisture in the stone masonry walls. The results clearly established that moisture in the walls is primarily from exterior sources (i.e. rain and snow) but that air ex filtration in localized areas is also a contributory factor. The information obtained from this monitoring program has been considered in the design of the restoration program which will be underway shortly.