Brick is porous, which means paint doesn't just sit on the surface, it soaks slightly into the material itself. This makes removal more involved, often needing a combination of pressure washing and a chemical paint stripper matched to the brick's porosity to avoid discolouring or damaging the surface underneath.
Render is generally smoother and less porous, so paint sits closer to the surface and can often be removed with less aggressive treatment. The risk with render is different, it's more prone to cracking or chipping under excessive pressure, so a gentler, more controlled approach usually gets the better result.
In both cases, testing on a small, less visible section first is standard practice, since the exact paint type, age and surface condition all affect how it responds. What works cleanly on one wall won't always translate directly to another, even on the same property.
