1. Why were the slates covered with asbestos ?
2. The copper valley flashings are all but worn out and in the last 20 years have been patched with roofing cement at least 4 times and just the last big rain we had there was a lot of water coming through the ceiling into my sons bedroom. Checking the attic it still looks like the copper valleys are leaking. The roofer says that he cannot slide new flashing under the slates as the slates are nailed too close to the edge. Is the any way around this? Is there no way to seal the old flashing? The roof guy wants to replace the whole roof and I am trying to avoid this if possible. Any ideas?