Seems to me like, given the expense and duration goals, you'd be much better off forgoing steel entirely and creating a stone gravity-bound structure, and making the places where you can't go with stone easy to repair or replace, something for which I'm not sure structural steel is ideal.
> Our other option is slate. Slate roofs have extremely long lifespans and are extremely attractive. But, like copper, they’re more expensive upfront, and require more specialized skills to install (since they’re less common). A slate roof is also extremely heavy, putting more weight on our framing and increasing the risk of damage during an earthquake.
OP apparently doesn't know that slate roof have to be repaired all the time. Slates will age and break, especially if they're nailed (because the metal expands and cracks the slate).
I've spent 10 years with a slate roof, and it has to regularly be fully checked, and missing or breaking slates replaced (because they'll leak).
Screw slate, give me terracota tiles any day of the week. Lighter, way more flexible, and easier to replace when they invariably break.
Yes, another way to spell Slate roof = work. The reason is simple: Slate, layers of fossilized leaves, has a rough surface and frost and the weather in general will work on it and split the layers apart, seeds will find enough purchase to germinate (the handy supply of water certainly helps) and lichen and moss just love to grow on slate.
This whole article to me reads: "I'm planning on an overpriced construction for my house and need a plausible excuse'. It's a status thing and a discussion piece, not a serious project. If you want to build for a millenium: copy the Romans. Done. And even then you're going to have to re-do all the trimmings every so many years because they'll all give out with use. Even staircases made out of solid stone will wear over such time spans.
> Slate, layers of fossilized leaves, has a rough surface and frost and the weather in general will work on it and split the layers apart, seeds will find enough purchase to germinate (the handy supply of water certainly helps) and lichen and moss just love to grow on slate.
25 years ago, when I saw some roofers working to replace an old slate roof on a church outside Philadelphia with asphalt (I was horrified), I asked them why they were taking this (to me) horrible step, since my parents live and stay in homes in the UK with slate roofs that are between 300 and 500 years old.
The roofers laughed and said "yeah, that's probably welsh slate. The stuff here in PA is so much worse than that. Freeze-thaw will destroy it in 20-40 years"
So the observations you're making about slate are true but only for specific slate quarries. There are slate sources that can provide slate which could last for centuries.
The UK seems not to have much of an issue with moss & lichens causing problems with slate roofing (it grows but it isn't much of a problem).
I think the roofers would have said "oh, and the upstate NY stuff is pretty good too". The slate I've looked at in detail in PA really is pretty bad. It just isn't as dense as the welsh stuff in the UK.
Slate is not made of fossilized leaves; its foliate structure arises from the metamorphic process as flakes of clay (aluminium silicates) align and merge into sheets under transverse pressure. Any organic material present in the original sedimentary deposit will typically result in a graphite inclusion.
Hm, ok! I totally bought this when it was related to me but you are absolutely correct. It always makes me wonder if there is a faster way to cross check everything in your head to fish out the false stuff other than people taking the time to point these things out. Thank you.
I wish there were a service to sort through the ideas in my head and point out the flawed ones too — until I realize that a) I'd have to agree to one implanted product preference for each hundred thoughts scanned, and b) many of my thoughts would be placed behind trigger warning overlays.
I don't think slate roofs are that bad - our house is an exceptionally exposed spot and has a slate roof and we lose maybe one or two slates a year to storms. Our wooden windows and doors are a far bigger maintenance headache than our roof.
When I got to the part about wood windows it dawned on me that the author is less clued in than he lets on. Wood windows are a maintenance nightmare. You can't open them half the year in a humid climate, or all of the year in an old house that has settled. No window is going to last 1000 years so might as well pick one that will make you hate your house less in the interim.
And one or two slates per year is indeed manageable, assuming they are in an accessible spot. If you're unlucky they are not and then you have to get to the spot to apply your fix without breaking more slates, which can be quite a bit of work (remove slates to make a path to the spot, fix, then rehang all the others, and hopefully they were uniform).
I've had one storm bad enough in NL that we lost some rooftiles, which were fairly easily replaced. Since in the rest of the country people had lost whole roofs and other houses in the same street were in much worse shape and comparing with the few houses that had slate I'm pretty happy with my good old 'dakpannen', which are almost maintenance free (due to the angle of the roof).
The worst is thatched roofs. Those require pretty much bi-annual upkeep and tend to become rodent infested. They look pretty in the first 10 years, a bit garish in the second and depending on their state of maintenance horror shows in the last 10. I'll never live in a house with one of those, people like them for status but they tend to be people that can afford to pay others to do their work for them.
> Our other option is slate. Slate roofs have extremely long lifespans and are extremely attractive. But, like copper, they’re more expensive upfront, and require more specialized skills to install (since they’re less common). A slate roof is also extremely heavy, putting more weight on our framing and increasing the risk of damage during an earthquake.
OP apparently doesn't know that slate roof have to be repaired all the time. Slates will age and break, especially if they're nailed (because the metal expands and cracks the slate).
I've spent 10 years with a slate roof, and it has to regularly be fully checked, and missing or breaking slates replaced (because they'll leak).
Screw slate, give me terracota tiles any day of the week. Lighter, way more flexible, and easier to replace when they invariably break.