On Saturday, June 1, 2019 at 9:31:26 AM UTC-4, Davej wrote:
On Friday, May 31, 2019 at 7:10:31 PM UTC-5, Clare Snyder wrote:
On Fri, 31 May 2019, Davej wrote:
[...]... but the easiest solution would be a wall
that incorporates a drain. Does this exist? Thanks.

There is if you build it that way.

That is the puzzle. I could remove the concrete block wall,
install a series of drains, cover the drains with styrofoam
blanks and then pour a new concrete wall which would then
have pockets for the drains.

If the wall is otherwise OK, why would you do all that instead of renting
a concrete saw and cutting off the end of the patio where it meets the
wall? It's one cut with the saw, no? And HD and similar have troughs
and grate covers that fit 4" pipe.