Joseph Meehan wrote:
PipeDown wrote:

"Goedjn" wrote in message
. ..

Does anyone know of an objective way to decide whether
a salvaged roofing slate is in useable condition or not?
I've got a whole pile of them in my basement,
so they're free; if they'll last as long as a cheap-ass
asphalt shingle, that's a win for me, because it means
I don't have to replace the skip-sheathing with plywood.

--Goedjn



If the edges are in good shape and they are not spalling or
delaminating (splitting along the layers) and the nailing holes are
intact, I'd say they are servicable.

Try soaking one in water and freezing in the fridge overnight to see
how it stands up if they look porous (they should not).

Installed properly, they will last a heck of a lot longer than cheap
ass shingles. Could be a big win for you.


Good advice.

I will only add that there are many kinds of slate. The good stuff has
a life span rated in centuries, while the cheaper stuff may be rated in
decades. Even the cheaper ones last a long time.




The life of the slate depends on the region the slate came from. The
slate in my region usually lasts 75 to 100 years on the roof. Some slate
belt's slate can last a few hundred years, but the hardware that holds
the slates on the roof rarely lasts as long, so the roof would generally
have the slates removed and re-installed after about 100 years. My slate
roof is 75 years old and I expect it to last about another 25 years
(according to a roofer who looked at it).

Rob