Why heavy waterproofing rusts metal sheets
Heavy waterproofing encourages rust on sheets. Water gets trapped under the layer, and as the waterproofing perishes it holds moisture against the metal and lets water back up underneath it. That is why we keep waterproofing to a minimum and fix the sheeting itself.
Flashings fitted properly
All roofs have flashings that join the vertical, horizontal and diagonal surfaces together, and we know which flashings go where.
A badly fitted flashing is one of the most common causes of leaks, especially where an extension joins the original house.
