I have an internal brick wall which must be allowed to breathe to prevent damp. Does chalk paint have microporosity? Colin MORTON oes oes
The Rust-Oleum Chalky Finish Wall Paint is a durable and scrubbable paint but does not state it is breathable.
Assuming the internal wall is clean, dry, sound and prepared as detailed in the technical data sheet we can recommend Keim Optil for a highly vapour permeable option.