Watertightness of masonry walls: an overview

Masonry walls are commonly used in a range of different climates and there has emerged over the years a consensus amongst building practitioners that, if correctly installed and adequately maintained, masonry walls clearly achieve adequate long-term performance. Two key features of masonry walls contribute in providing acceptable performance by mitigating the effects of wind-driven rain: the evident capacity of the exterior masonry to absorb and store rainfall; an open cavity behind the exterior masonry cladding to drain infiltrated water. Recent European trends in respect to energy conservation have building practitioners considering applying spray-in-place insulation to fill the open cavity in walls. As well, there is an emerging interest in low energy wood frame construction for moderate climates such as those of North-western Europe. Such construction would incorporate brick veneer cladding with reduced space behind the cladding. Knowing the degree of water infiltration of brick masonry walls might help provide a useful estimate of moisture loads behind the cladding and hence improve HAM-simulations of these new concepts. Extensive research has been carried out over the years to assess the performance of masonry walls systems with regards to watertightness. This paper offers an overview of research on water infiltration through brick masonry walls. Assessment protocols and test methods are discussed and where possible test data amongst the different methods compared