Grumps wrote:
snip

My house has never had a leaking pipe in 20 years. Does the screed really
'leak' onto the pipes to cause damage?
Yes.
It corrodes.

I'm going to go with buried pipes. If they last 10 years, good. If they last
more than 10 years, even better. If they leak, isn't that what insurance is
for?

Bare pipes don't last very long.

Properly treated, or trunked pipes should last much, much longer.
Insurance may not cover 'normal' maintainance.