Lead and steel are the main materials that are used with seaming pliers, but there are some others as well. Read on to find out more….
Lead
The Lead Sheet Association (UK) issues guidance on the use of lead, using a coding system.
Lead codes are based on pounds weight per foot square. The higher the code number, the thicker the lead. Different thicknesses of lead are used for different purposes, for example code 7 is used for larger sheets of lead on historic roof repairs.
The recommended thickness of lead that is most commonly used on a roof varies from 1.3mm (0.05 inches), 1.8mm (0.07 inches) to 2.2mm (0.08 inches) or codes 3, 4 and 5.
Sheet metal is generally considered to be a piece of stock between 0.15mm (0.006 inches) and 6.25 mm (0.25 inches) thick, so this is the maximum thickness for use with seaming pliers.
The codes also indicate where on a roof the lead should be placed. Seaming pliers are used with flashing which is code 4, and on flat roofs, valleys and gutters which is code 5.
Steel
There is a standard measure, called the gauge, which uses numbers to indicate the thickness of a sheet of metal. A higher number indicates a thinner sheet, except for zinc were a higher number is used for a thicker sheet.
The gauge was developed based on the weight of the sheet for a given material, including aluminium, copper, and stainless steel.
Manufacturers of seaming pliers recommend the gauge of sheet metal to be used with the pliers for maximum effectiveness.
This information can be found in the product specification and tells the user which seaming pliers will work most effectively i.e. make the bending of a piece of sheet metal easiest, with which material.
However, some people who have more than one pair of seaming pliers find that they have a favourite pair, and use them for all of their seaming tasks.
Aluminium
Seaming pliers can also be used with aluminium sheet metal 0.9mm (0.03 inches) thick or 19 gauge.
Aluminium is used as flashing on a roof because it is a lightweight material that is inexpensive and durable. Aluminium roofing resists rust and corrosion. It is also easy to form.
Zinc
Seaming pliers can be used with zinc sheet metal of 0.9mm (0.03 inches) thickness or 14 gauge.
Zinc is used as a roof covering because of its zero or low maintenance life of over sixty years and clean, clear lines.
Copper
Seaming pliers can be used with copper sheet metal of 0.58mm (0.02 inches) thickness or 22 gauge.
Copper is used on roofs because it is malleable which allows a roofer to make small, detailed pieces of flashing or guttering on-site. It is also weather-resistant.
Stainless steel
Seaming pliers can be used with stainless steel sheet metal of 0.45mm (0.01 inches) thickness or 26 gauge.
Stainless steel may be used as a roof covering because of its high resistance to corrosion and for its cosmetic appearance. However, stainless steel is not easy to work with because of its lack of malleability.