Teeth

There are quite a few design ideas that we like that are completely dependent on the skill of the laborers. Ultimately, all structural design is dependent on the skill of the laborers – it’s not like we engineers are on site actually building anything – but some details are more sensitive to skill levels than other.

When we are dealing with unreinforced brick walls, like those that make up about 95 percent of the walls in New York, our preferred detail for repairs and alterations is to “tooth in” new brick by interleaving the new brick with the old. Toothing has a number of advantages, including compatibility of materials and an even distribution of load, but it requires very careful cutting out of joints and setting new bricks in place.

Here is a picture of it being done right (and a close up), unfortunately back-lit by the outside daylight on the other side of the wall:

New masonry walls are built with steel reinforcing, but there’s little point in putting in reinforcing that will only extend a foot or two along the wall length, so we don’t bother in cases like this.