Answer
Apr 22, 2024 - 03:34 PM
What is happening is the water that falls on the stucco walls is running down the wall and it is seeping under the concrete slab between the wall and the slab.
From The pictures you can see a gap or separation between the wall and slab. When water is under the slab and then the slab is exposed to heat from the sun it will start sweating through the concrete and leaching out the concrete salts or efflorescence.
When concrete has been colored stain/seal or painted and efflorescence leaches out it pushes out whatever is on the way. This is why after cleaning the efflorescence you can see that the color has been removed from the concrete.
The solution is as follows:
1. Seal The gap between the wall and the slab to prevent more water under the slab. We recommend using SealGreen 116 Caulk and the apply SealGreen Finishing Sand.
2. After sealing the gap, you will have to re-apply the sealer/color again to the areas that are missing color. I suggest using a sponge or cotton ball to dab the color as opposed to brush. You can also apply the color/sealer mix with small prayer but do not flood the application because it may leave color streaks. A combination of spray and sponges combine will help.
Source: SealGreen Website
