How to fake this concrete effect with paint?

Question

I'm attempting to imitate this concrete wall (at least I think it's real concrete!), using acrylic paint.

For my initial attempt I was thinking of working with two grays (one slightly lighter) - First a layer of the darker color, followed with a watered down (and slightly patchy) later of the same, then a the lighter paint (maybe also watered down) where needed.

What are my chances of getting a similar effect? Do you have any tips or alternative approaches?

Thank you!

EDIT: I'll be painting on an already painted, solid wall (plastered brick).

Answer 1

You can use a natural sponge to make concrete like shadings. Use a light touch and dab the sponge. Turn the sponge often so you don't get a regular pattern. Practice first on some cardboard. You can start with either your darker shade or the lighter, see which you like the best. Go back over what you have done with a dry brush or rag to soften your work while it is still wet. Remember acrylic paint dries fast and darker.