Repairing or replacing a leaky metal roof

The terne metal roof on our church was painted six years ago -- and seven years before that when it was new. The last refinishing also included repairs for rust and leaks. Now the roof leaks again and is rusting at the seams. The roofing company told us that the roof would give a lifetime of service. What should we do now: Repair and repaint the old roof or put on a new one? Richard Blamey Fond du Lac, Wis.

In making repairs to the roof, be sure to use the same metal as the original material. If a different type of metal is used for patching, electrolysis might result, thus giving even more problems in the long run.

For a nonmetal repair material, consider a plastic autobody filler, such as Bondo, or its equal.

To expect another repair-and-paint job to last more than the previous ones may be overly optimistic.

The way to avoid these perennial repairs and repainting is to install a new roof. A new roof, however, will have its own problems of longevity, aesthetics, and maintenance. You might want to investigate the cost of various roofing materials that are appropriate to the design of the church.

Ask for comparative prices for fixing the old roof, using the original metal, against using plastic for repairs. Have the proposals include a written life expectancy of the repaired and repainted roof, then let the economics determine the issue.

Compare these repair costs and longevity with the cost of written bids for a new roof.

For those who don't know (as I didn't), a terne roof, according to Webster, is "sheet iron or steel coated with an alloy of about 4 parts lead to 1 part tin."