These are specially fabricated metal components covering seals or joints, to prevent water getting in, and protect the exposed edges of your building. If any objects, such as beams or pipes, penetrate the surface, then flashings will help deflect water away from the seams.
In the old days, this might have been done using birch bark, or lead. But with the advances in metals and precision fabrication, these are now mostly steel, copper, aluminium, or zinc (depending on your budget, and the finished look you’re after).
Aluminium is the most widely used flashing material, but in many instances is totally inappropriate, due to it’s propensity to oxidise, or pit. This is especially true for untreated aluminium in contact with other metals, wood, concrete, mortar, and other alkaline building materials.
At the upper end of the scale, Copper is used not only for it’s visual appeal, but also because of it’s malleability and strength. It’s easy to weld and maintains it’s integrity for decades, if not centuries, giving it a significant cost-advantage over time.
Zinc is also gaining in popularity since it’s softer and extremely malleable. It is completely recyclable and is an excellent replacement for older lead flashings.
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