Black spots in brick mortar

[rambling-panda]

Hey all,

I've just had a garage conversion; A wall was built for the new window. I've started to notice black spots appearing on the mortar surface. When I brush it with my finger it falls out. It's only been about 3 weeks since it was done and I don't want it to get worse.

What is it, is it an issue, and what steps do I need to take to prevent it?

Please see the attached.

Thanks all.

 

[noseall]

Hey all,

I've just had a garage conversion; A wall was built for the new window. I've started to notice black spots appearing on the mortar surface. When I brush it with my finger it falls out. It's only been about 3 weeks since it was done and I don't want it to get worse.

What is it, is it an issue, and what steps do I need to take to prevent it?

Please see the attached.

Thanks all.

It's bits of undissolved black mortar dye. Probably old (powdered) gear.

 

[rambling-panda]

Thanks. Why does it crumble away? Is it anything to be worried about and could I just refill it if needs be?

 

[noseall]

Why does it crumble away?

Mortar dye itself is not designed to harden. Pockets of undissolved dye will behave the same as undissolved lumps of sand etc. They will behave how they are supposed to behave - friable.

 

[rambling-panda]

Mortar dye itself is not designed to harden. Pockets of undissolved dye will behave the same as undissolved lumps of sand etc. They will behave how they are supposed to behave - friable.

Thanks for the information. Can I just fill those holes with new mortar if needs be?

 

[noseall]

Thanks for the information. Can I just fill those holes with new mortar if needs be?

Yes. Wet it first

 

[rambling-panda]

Yes. Wet it first

Cheers.