DavidM47 t1_ja0pyr2 wrote on February 25, 2023 at 11:44 PM

Reply to comment by CyberKingfisher in Tiling over concrete expansion joint by Scav54

I think you’re right that it’s a crack.

I’ve never seen such a perfect crack in a foundation before.

DavidM47 t1_ja0pkth wrote on February 25, 2023 at 11:41 PM

Reply to Tiling over concrete expansion joint by Scav54

I would make it the expansion joint in my tile.

Expanse of tile greater than 15-20 feet should have an expansion joint anyway.

DavidM47 t1_j5vcl1m wrote on January 25, 2023 at 8:43 PM

Reply to comment by OzAnonn in Is this mold in my chimney? by OzAnonn

There are many different types of mold. But I think for most of them, the smell (and definitely the biohazard) comes from the byproducts not the spores. So the smell could be gone but the discoloration remains.

DavidM47 t1_j5t9u0r wrote on January 25, 2023 at 12:23 PM

Reply to comment by OzAnonn in Is this mold in my chimney? by OzAnonn

The discoloration may be permanent even if spores are gone

DavidM47 t1_j5t6jwu wrote on January 25, 2023 at 11:48 AM

Reply to Is this mold in my chimney? by OzAnonn

OP, I was going to say that I don’t think it’s mold, because I don’t think mold can grow on concrete, but apparently it can! And it does kinda look like that when it does. Search for leaks. Check to see if you have a dead valley at your chimney. If so, you need to install cricket flashing.