The other thing this valley made
This valley did not only quarry slate. It made cement on an industrial scale, and some of that output went onto roofs and walls as rigid shingle. Those coverings are still up there, and they are not removed the way an asphalt roof is removed.
- 1 The ridge. The highest course, and on slate the one most often reset by hand.
- 2 The field. Slate on the older stock, shingle on the rest. Two very different clocks.
- 3 Valleys. Where leaf litter settles, and where a slate roof usually ends its life.
- 4 Wall flashing. The party wall of a row or twin, rising through a roof two houses share.
- 5 Penetrations. Holes cut on purpose. When access is awkward they get sealed instead of rebuilt.
- 6 The overhang. Where meltwater from a warm attic reaches cold framing and stops.
How to recognise it
Rigid, brittle, usually laid in a regular diamond or rectangle pattern, often grey and sometimes tinted. It rings hard rather than flexing underfoot, and it breaks rather than tears. On many houses it appears on a rear ell or a porch roof, replaced elsewhere but left where the work was awkward.
It weathers unevenly: the field can look serviceable while individual pieces have cracked through, particularly on slopes that take the freeze and thaw from both sides.
Why it changes the job
Older rigid shingle of this era can contain material that requires trained handling and controlled disposal rather than a dumpster. Any contractor working this housing stock knows that; the ones who do not are the ones who have not worked it. It is a question worth asking out loud before a crew starts, not after.
It also changes the price honestly. Removal is slower, disposal costs more, and those are line items rather than surprises. A quote that assumes an ordinary tear-off on a house wearing this material has not looked at the roof.
What usually replaces it
Almost always a modern covering, because the original is no longer manufactured in this form. The useful part of the conversation is not what goes on top but what the removal reveals: decking of an era when boards were spaced rather than sheeted, and fastening that was designed for a different weight.