How to get stubborn black mold off exterior brick
Standard scrubbing and degreasers fail on deep-set exterior black marks because the growth embeds into the material rather than sitting on the surface. Trying to force it with hard-bristled brushes often strips the surrounding mortar instead of removing the stain, leaving homeowners stuck between ruining the masonry or resorting to painting over it.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Using a hard bristled brush with a degreaser
- 2Painting over the brick and mortar
- 3Ignoring the marks entirely
- 4Hiring an expert to clean it with hypo and correct PPE
- 5Painting over the stained metal
- 6using a power washer with RainX Shower Glass Cleaner
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“I tried a hard bristled brush and degreaser which worryingly had more impact on the mortar than the brick.”source ↗
“Can the black marks be cleaned or is it a characteristic of the brick?”source ↗
“We are going to a Lowe's tomorrow and are looking for suggestions on what to buy to put in the containers to help get the stubborn Grime off (we are lazy and haven't washed the house in the 6 1/2 years we have owned it).”source ↗
“What is the best way to fix this? It’s like a black mold that is not able to be scrubbed off and has permanently stained the metal?”source ↗
“The mold is embedded into the metal , it won’t scrub off”source ↗
“Looks like the kind of mold that gets deep into the paint, scrubbing won't do much at this point”source ↗
“Yep exactly right. I’m thinking my only option is to like paint over it? Just unsure the best solution or what products to use for this”source ↗
Where this came up
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