Butter soft
Butter soft
I have tried Lag Shield Anchors in the mortar joint near the top of the building and had the last few courses actually start to lift up (just the immediate bricks above the lag anchor). Moved the lag anchor to the brick and it just started to disintegrate the further I drove in the lag bolt. It is amazing the difference between the old (at least a hundred years I'd guess) and newer brick. I don't even need a hammer drill to make a hole in the old brick it's so soft. Sometimes I worry the hammer drill or rotary hammer is gonna really mess up the brick.:roll: For little stuff I'll use plastic inserts in the old brick but with the forces on the point of attachment definitely want something solid especially when its a tension force from the point of attachment instead of being a shear force. I try to use the old point of attachments from the original Knob & Tube wiring because they're longer then newer ones so I feel they help to spread out the forces more, instead of concentrating it on two or three bricks.
Usually the construction is an outer course of brick with a hollow space then an inner course of brick, but not always. I tend to use a slightly smaller drill bit then the manufacturer suggests to get a tighter fit.
A lot of the time the attic is the 3rd floor and is finished.
I use to know what the bricks were made of but it escapes me at the moment when I remember I'll post it up. It seems like I remember the material was locally quarried.