What is racking back?
Racking back is a temporary, stepped end to a brick wall: each course is set back from the one below, forming a staircase that later work can join on to, course by course. The Dutch term is vallende tand. Bricklayers rack back when a wall has to stop for a while, for example at a break in the work, or when the corners (leads or quoins) are raised first and the wall between them is filled in afterwards.
Racking back or toothing
- Racking back. The end steps back diagonally. New bricks are simply laid in a mortar bed, with bed and perpend joints that can be filled normally.
- Toothing. The stopping end stays in one place over the full height, with alternate bricks projecting and set back. The pockets must later be filled with bricks that fit exactly.
Racking back generally gives the better bond, because with toothing the top joint of each inserted brick is hard to fill completely. So rack back wherever there is room.
| Racking back | End steps back diagonally. Joining on: bricks laid in a mortar bed, with bed and perpend joints that can be filled normally. Bond: generally the better bond. |
|---|---|
| Toothing | End stays in one place over the full height. Joining on: pockets must be filled with bricks that fit exactly. Bond: the top joint of each inserted brick is hard to fill completely. |
Method
- Keep to the bond. Set each course back in line with the bond you are using, so the new work joins without cut pieces.
- Check the rake. A neat rack has a straight diagonal line; hold a straightedge against the brick ends to check it.
- Keep the steps clean. Scrape off mortar droppings before they harden.
- Dampen absorbent bricks when you join on, so the new mortar bonds well.
- Fill every joint, including the perpends against the old work.
Common mistake: steps that are irregular and ignore the bond. When you join on, you need cut pieces and the bond drifts out of line.
Related terms
- Vertical toothing
- Bond pattern
- Bed joint
- Perpend joint
- Mortar
- Bricklaying
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