Terms & Tools: Metals
brace
Diagonal framing member that provides stiffness to keep plane (wall, table top, etc.) from racking by creating a triangle.
counterflashing
Metal that is anchored into a building and over the flashing coming up from the roof. Helps to prevent water infiltration. Often found where the a vertical face meets the roof.
compression fold
need definition
expansion joint
The connection of metal sheets or pans that allows for the expansion and contraction of metal.
flashing
A continuous piece of metal used to prevent water penetration in roofing systems. Usually found at an angle or joint like where the roof meets the chimney, under an expansion joint, and in the valley of a roof. Sometimes covered with "counterflashing" to provide extra protection against water infiltration.
hem
The edge of sheet metal that have been folded back on itself. A hemmed piece of metal has significantly increased strength and rigidity.
lock seam
A type of metal joint that provides a mechanical connection and, when not soldered, allows for expansion and contraction of metal. A flat lock seam of sufficient width (3/4" minimum) provides excellent watertightness. Also called a "compression seam."
mechanical connection
A connection of direct contact between two pieces. The joining of elements by fasteners, such as screws, bolts, or nails (instead of non-mechanical, meaning joining by adhesives.)
pan
A metal sheet with hemmed edges that lock together to create a water-shedding. Usually used as roof covering, flashing, or counterflashing.
pintel
A metal pin or bolt used as the pivot for a hinge, usually inserted into a gudgeon.
proud
Describes an feature or element that is raised, not flush with the surface.
verdigris
Copper salt, of various types. Also referred to as Copper(II) acetate. For centuries has been used as paint pigment for its blue/green color and as a fungicide. Different areas will have different kinds of salt: coastal will usually have more sodium chloride because of the ocean, urban/industrial areas will have more complex salts.
white lead
(PbCO3)2 Pb(OH)2 Pigment that was used in lead paint because of it opacity. A mixture of the carbonate and the hydrated oxides of lead. Also known as "flake white."