A chase wedge is a hand tool used for forming or shaping soft, malleable metals such as lead and copper sheets. It is one of a range of ‘lead working’ tools suitable for forming lead and other sheet metals into desired shapes (known as bossing). It can also be used for dressing (arranging) sheet metal into position.
An example of when a chase wedge would be used is when fitting a new or replacement piece of lead sheeting (known as flashing) around a chimney. The edge of the chase wedge is used to dress the flashing in place around the various angles and intersections of the chimney. For more information, see our page: What are the basic parts of a chase wedge?
Flashing is used to seal and protect the joints in exterior building structures such as a roof or roof-mounted constructions e.g. a skylight or a parapet. It is installed to prevent rainwater – especially the UK wind-driven rain – from leaking into the building itself.
Why is it called a chase wedge?
Many manufacturers describe a chase wedge as a tool for chasing roofing materials.
…explain what ‘chasing’ means!
A ‘chase’ is a groove or a channel that has been cut into plaster or brickwork to hold electric cables and plumbing pipes, for example. Or in this case, metal sheets for flashing.
To ‘chase’, therefore, means to cut into brickwork or plaster and create an indentation.
A chase wedge is used to assist with ‘chasing’ a wall when inserting a sheet of flashing, for example. The edge of the tool is placed on the flashing and a gentle blow is applied to the back of the tool with a mallet. This will drive the flashing into position.
So, a chase wedge is a wedge-shaped tool used for bossing and dressing lead and other sheet metal, that is, ‘chasing’ roof materials. Hence its name – chase wedge.