On Tue, 15 Jan 2013 22:25:31 -0600, "ps56k"
wrote:

We have a concrete patio that is somewhat shaded by the house from the
afternoon sun.

We have a problem with green gunk growing on the surface...
because after it rains, the water does not get the sun to dry quickly... so
green gunk.

After we power wash the patio,
is there something we can put down to help seal or inhibit the growth.
I think I've read about the usual sealers being not good
as they cause the concrete to become slippery when wet...
along with the need of the concrete to "breathe"..

I'd try washing it down with clorox & see if that is enough.

If the patio was done right, with a brush finish, no amount of sealer
will make it slippery. [epoxy might-- but sealers will soak in and
leave the texture.]

Caution with the sealer-- It is a *sealer*. It will seal in, not
cover up, any stains, dirt, vegetation-- Make sure it is *really*
clean before you seal it.

Jim