Reinforced or Non-reinforced wall:
Non-reinforced walls cannot carry high stresses and are generally used as parapet walls; sometimes buildings, of 16 story heights, have been built with non-reinforced masonry – Reinforced walls are reinforced with vertical and horizontal steel reinforcements and are less thick.
Composite masonry walls:
Usually constructed with an outer wythe of stone or facing brick and a back up of hollow concrete block masonry – The two wythes are bonded together by steel horizontal joint reinforcements or by headers from the outer wythe that penetrate the back up wythe.
Since exterior walls must resist water penetration and heat transfer, these walls are built with internal cavities – Masonry cavity walls consist of an inner, structural wythe and an outer wythe of masonry facing – These two are separated by a continuous airspace that is spanned only by corrosion-resistant metal ties that hold the wythes together – Cavity walls prevent water from reaching the interior by interposing the cavity between outside and inside wythes of the wall – When penetrating moisture reaches the cavity, it goes down and is caught by a thin, impervious membrane called flashing and drained through weep holes to the exterior.