What is vertical toothing?
Vertical toothing is a temporary, vertical end to a brick wall in which alternate courses project and are set back, so that masonry built later can be bonded into it. Seen from the side, it forms a straight vertical line of teeth and pockets, like a comb. The Dutch term is staande tand. You use it when a wall has to stop for a while, for example at a break in the work, an opening left for materials or a wall that will be joined on later.
In Dutch the term has a second meaning: in some bond patterns the bricks form a vertical line that is also called staande tand.
Toothing or racking back
- Toothing. The stopping end stays in one place over the full height. The pockets must later be filled with bricks and mortar that fit exactly.
- Racking back. Each course steps back a little, creating a staircase. New work joins on course by course, with bed and perpend joints that can be filled normally.
Racking back generally gives the better bond, because each new brick is simply laid in a mortar bed. With toothing, it is especially the top joint of an inserted brick that is hard to fill completely. So choose toothing only when there is no room to rack back.
Application
- Keep to the bond. Let the teeth project in line with the bond you will continue, so the new work connects without cut pieces.
- Keep the toothing clean. Remove mortar droppings from the pockets before they harden.
- Dampen absorbent bricks when you join on, so the new mortar bonds well.
- Fill all joints completely. Press the mortar firmly above and beside each inserted brick; hollow joints become cracks or leaks.
- Consider ties. When an internal wall is connected later, stainless wall ties or wall starter kits are often used instead of toothing. Follow the structural engineer’s instructions.
Common mistake: filling the pockets later with broken pieces and a smear of mortar. The connection is then weak and will eventually show as a crack in the facade.
Related terms
- Bond pattern
- Quarter bat
- Half-brick wall
- Mortar
- Perpend joint
- Patching
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