Raising a new roof
I sing in a choir every Sunday morning, in the choir loft upstairs at the back of our large church. We sometimes think we are nearer to Heaven back there, but more importantly we are closer to the ceiling. From our vantage point we can see the crumbling plaster, adding an extra tremolo to the sopranos when it rains.
You see, the roof leaks from a series of long, brittle fractures in the cladding. There are 14 main leaks at the moment, but that could quickly turn into a torrent, according to the building consultants who have studied the situation.
The church was built 70 years ago, and is on its original copper roof. Seven decades is a long time, but copper roofs are supposed to last 80-120 years. The ballpark estimate for replacing the roof with another copper one is close to half a million dollars. No matter how cheap the current price of copper is, we’re talking about a lot of copper. It will take many bake sales to pay for this roof.
I was talking this week to Father John Mullins, the young priest who has recently been assigned to our parish. When he heard I was a geologist involved with a mining magazine, he asked me if we should replace the roof with copper or steel (painted green to look like aging copper). What do I know? Having heard about the weight advantages of aluminum, I asked him if he had considered aluminum. He said he had.
Those three metals are the sole materials that he is considering as protection for the aging building. I couldn’t help noting that he was placing his faith in metals to perform a really important job over a long period. His main consideration is which one would be most cost-effective. (Steel would cost half the price, and we don’t know the price of an aluminum roof). He also wonders whether acid rain or changing weather patterns might corrode any of these metals more quickly these days than in the past.
A few weeks ago I was interviewing Peter Goudie, executive vice-president of marketing for Inco Ltd., for a special issue we are preparing about the giant nickel-maker (CMJ April 2002). He also referred to long time lines. When asked when he thought nickel would be in short supply again, he answered, “That depends on when the world fully recovers from the economic downturn that we have just gone through. The important thing about nickel is the amount of time it takes for a greenfield project to get into production….”
Metals are a slow business. It takes a long time to find them, to plan and develop them for exploitation. This is an immutable factor in the mining/metallurgy business that has to be taken into account no matter what’s in fashion amongst investors in any given year. Once metals are in use, it takes a long time for them to wear away. That’s their big advantage, more significant than their cost in many applications.
If anyone can offer advice on the best metal for long-term roofing use in today’s climate, I will pass that information along to Father John, and will make it available to our readers as well. By the way, are there any suggestions about what to do with five tonnes of gently used copper cladding?