Joe Bobst wrote:

Labor -- how labor intensive is it to strip slate from a garage roof in way
which won't damage it?

Very labor intensive, nearly impossible for some varieties of slate
(Pennsylvania slate, for example).

is it possible to store half a garage roof's worth of slate
in the unheated garage

Not recommended. Old time slaters always buried a lot of spare slates in the
ground stacked vertically under the eaves so that falling rain always kept them
moist and ready for use.

annual maintenance of $300 or so to keep
it sound.

In 20 years that works out to about the price of new asphalt shingles and
you've still got the roof over your head. And besides that the roof will still
look great. IMO, the $300 annual cost may be on the high side. Don't talk to a
roofer, find an honest-to-john slater. Properly cared for a slate roof will
outlast your grandchildren. HTH

I figured it wouldn't be easy to rassle a bunch of rocks off the roof and keep
them sound, but I figured it was worth checking.

I agree that it's worth keeping the slate on the house, but it's looking like
keeping the garage roof in slate is not going to be worth it.

Is there any other use for old slate tiles? Building garden walls? Paving a
patio? Making a walkway? Or is the stuff just too slippery and brittle?