[sologoub]

Materials may cost that, but you are not getting a roof replaced for $1,700. Maybe $17,000 and even then it’s pushing it on the coasts especially. Labor and other overhead costs have really gone up and contractors don’t want to deal with small jobs. Sad really.

I’ve never seen slate roofs in California, so not sure if these are to code here. We looked at metal and other materials, but the problem is the weight is different, so now you are engaging an engineer to evaluate structure, submitting plans, dealing with code updates. Or just new asphalt shingles every 15-20 years. The payoff isn’t there and folks don’t tend to keep houses for generations, unlike in the UK.

[PaulDavisThe1st]

There is very little acceptable roofing slate available in the USA. PA has a few quarries that provide it, but according to roofers (in PA) that I talked to, it is still nowhere close in quality to, say, Welsh slate. Too many voids which when coupled with much more severe freeze/thaw cycling in much of the USA leads to early failures.

I think you may be overestimating the extent to which UK houses are held for "generations.

[bombcar]

And even if you import Welsh slate, you may have to import workers, too.

Because if you're trying to use building materials that the local contractors are not familiar with, you're going to have a bad time.

[londons_explore]

Slate isn't the only material with decent longevity. Ceramic and concrete tile should both last 100+ years.

[sologoub]

In my comment I said we looked into metal and other materials, but all increase weight, requiring engineering evaluation of the house and likely reinforcing the structure. Ceramic and concrete tiles are common here, but have the same problem. Don’t know about slate, but for the tiles you mention underlayment still needs to be replaced every 20-30 years at least requiring these to be removed and reapplied. Since labor is the major cost driver, it’s basically like paying for a new roof.