We had our foundation repaired a few weeks ago and found time, and dry weather, this weekend to get it painted. In prep, I first hosed down the portions of the walls that had not been repaired and then scrubbed with a firm bristle scrub brush as well as a little water and dish soap. The amount of dirt that came off the walls that looked clean to the naked eye was a bit repulsive. Anyways, we let them get good and dry in the heat that we had last week.
I was also able to sneak outside during nap-time to get all the cutting in done.