The mass walls to be retrofitted could include both multi-wythe solid brick walls, and exterior brick with a hollow clay block infill/backup wall.  The interior of mass walls may be finished with plaster, often gypsum or lime-cement based, and sometimes installed over furring strips and/or lath. In some cases, a layer of bitumen is applied between the interior finish and the masonry. It is necessary to remove any existing interior furring, lath and plaster to expose the brick structure from the interior for retrofit since they could be moisture sensitive (like gypsum), or form a void that can create unintentional air leakage (such as furring and lath).  Photograph 1, Photograph 2, Photograph 3 and Photograph 4 show conditions after removal/demolition of the interior furring, lath, and plaster.  No one said this was going to be easy. #Brick #walls #Insulation #pub

Load-bearing brick walls are tricky to insulate. Here’s why: if you insulate the wall on the interior, you’ll make the bricks colder during the winter. As we know from the psychrometric chart, cold bricks are always wetter than warm bricks. Once the wall is insulated, the escaping heat that formerly passed through the bricks is no longer available to drive out the moisture. So your wet bricks stay wet for a long time. In some cases, repeated cycles of freezing and thawing can permanently damage the bricks, causing them to fall apart. #Brick #wall #insulation #renovate #pub

The first step in addressing the problem is determining where the wythes are delaminating. The simplest method is to sight down the face of the wall with one eye, studying the surface for bulges. Another approach is to look inside the wall cavity with a borescope, an inspection device consisting of long rigid or flexible tube with a lens at the end. After boring a small hole in a mortar joint, an engineer can insert the borescope and look behind the veneer bricks to examine the cavity and the condition of tie bricks or metal ties. #multi #wythe #brick #walls #mass #pub