Q: Why does the slate have to be replaced?
A: The original slate roof is at the end of its serviceable life. The tiles are over 140 years old. The slates have weathered to the point of “softness,” where they can easily crack, split, or fall out. The steel nails holding them have rusted and no longer provide much holding power. The original underlayment- asphalt felt has deteriorated to a point of ineffectiveness. If a slate falls out, the underlayment will not prevent leaks.
Q: How much slate will be replaced?
A: All slate tiles will be replaced including the tiles on the bell tower.
Q: Instead of replacing the entire roof could only the defective slates be replaced?
A: Repairing the roof will increasingly become cost ineffective. Any repairs will probably not have lasting value, as other areas of the roof will likely fail. Resulting leaks will certainly damage underlying structures. Eventually, the entire roof will have to be replaced.
Q: Was synthetic slate considered?
A: Yes. Each bidder was asked to submit a bid for natural and synthetic slate. Three bidders responded about the synthetic slate. The price for synthetic slate was about 85% of the price for natural slate. Natural slate was determined to be the best option because it was the original material of the chapel, is considered to be more attractive, and is more appropriate for a historic chapel. Synthetic slate does not have a long history, so there are many unknowns.
Q: How was the price determined?
A: We received five quotes. Three vendors provided similar bids for $100,000. We added a 10% contingency.
Q: How were the bidders selected?
A: We developed a detailed RFQ and selected ten potential vendors. Five potential vendors were members of a slate contractor association (more than 75% of their work is with slate). We added five local vendors to the bidder list. Five vendors responded.
Q: Where will the slate come from?
A: We expect to use slate from Vermont.
Q: What color will the new slate be?
A: It will be the original color – weathering green; however, since it has not weathered it will be brighter than the current slate.
Q: How many slate tiles will it take to complete the replacement?
A: Slate is sold in “squares.” Each square contains 100 sq. ft. of slate tile. The replacement will require 40 squares of slate, or about 4,500 tiles of slate.
Q: Will the copper flashing be replaced?
A: Much of the copper flashing will have to be replaced as the tiles are removed near the flashing. The copper on the bell tower appears to be intact and will be preserved if appropriate.
Q: Will the chapel schedule be affected by the roof replacement?
A: No. The process will take approximately four to six weeks, so the work will be scheduled outside the chapel calendar.