Can you tell me what this stuff is and what will remove it?

[troyt 14]

I don't think that this is mold, I could be wrong, but on brick it seems to be black, but on siding it is yellowish in color. I guess could be rust, does chlorien in the local water stain? It seems that all of this is where sprinkler systems hit the houses in the area. Attached are some examples.

[Mike Williamson 198]

The first pic is rust stain from the irrigation system. Not sure about the last two.

[troyt 14]

I have read that not much will take off rust, or since it is on Vinyl siding will it come off, but not on brick?

[Paul B. 523]

Phosphoric acid based products such as Prosoco's Ferrous Stain Remover or Oxalic acid based products such as White-Ox (Rust-Away) will remove rust stains from vinyl and brick.

Rust will be orange color on brick also - it's most likely mold & mildew or slight chance it could be carbon deposits.

Pool Shock/Chlorine (liquid) will remove mold mildew.

"No" - chlorine will not stain materials (it will whiten or bleach some materials)

1st pic shows "Rust on Brick"

2nd and 3rd show "Mold & Mildew on Brick"

[troyt 14]

Thanks Paul,

Those photos helped alot, and the chems.

[Paul B. 523]

You are welcome!

[James 625]

I agree with door # 1 and 3 # 2 looks like a black top sealant was applied

[Paul B. 523]

James,

What's interesting about door #2 is that the mortar joints both horizontal and vertical are all (relatively) clean on the bottom rows of brick. May just be black bricks.

[James 625]

look at the very bottom ( Thick black resydue )

[Scott Stone 604]

IS the black stuff thick and hard, or can it flake off? Are there little bumps all over it, or is it smooth? Is the water in your area exceptionally hard?

I have seen stuff like this in carwashes, and it is Calcium buildup. It is most common in hard water areas. The Prosoco stuff Paul recommended will take it off, but you will need to work at it. Think a sitff brush, applied on straight, and scrub your little heart out.

Maybe RFitz knows what to do??

Scott Stone

[troyt 14]

I will stop by this afternoon and get a better discription of the black stuff on the bricks and post.

[troyt 14]

Sorry I haven't gotten back on this one till now. I stopped by the other day and gave it a rub. It appears to come off almost like eraser rubber. I think it is caused by rain water splashing up off the tar/sealer then sticking to the brick. Should come off with pressure and heat I would imagine.