We are about to start a flat seam stainless steel roof on Thursday. The roof we are removing (pictured middle and bottom) to make way for new roof is also a flat seam stainless steel roof; its only seven years old and it has a fatal leak.
We didn’t install the roof; but I have tried a bunch of times to fix it and it just wouldn’t work. This roof is made up of 16″ X 22″ panels of stainless steel; each edge is turned up 3/4″ to make interlocking tiles. After the tiles are laid out the seams where each panel meets are hammered down flat. The seams are fluxed and then soldered (look at the copper flat seam roof on upper right); this method has been in use for about 600 years and is very durable if done properly. There is no reason why this roof won’t keep the building dry for the next 90 years if done properly.
You cant rush this work; it takes lots of time and in 600 years no one has found a faster way.
Look at the photos, notice anything odd? Ok, why would a stainless steel roof have rust on it? Wait, why does some of the metal look like it has gold paint on it? If you solder these panels then why do I see black tar and gray caulk?
The previous contractor used a few different types of metal on this one; we have stainless steel (dark gray), terne metal or tin (gold looking), and plain old galvanized steel (rust stained).
The mismatched metals are all in places that would be installed toward the end of the job; he probably ran short of stainless which is really expensive and grabbed any old metal he had laying around. There is approximately 1260 linear feet of soldered seams on this roof and just about half of them are cracked.
There are lessons to be learned here; but I’m tired and I have 1260 linear feet of soldering to do tomorrow.