White powder

[john2189]

This is white powder on the mortar joints in the basement of our church outside walls. Is it just the lime leaching out of the mortar? It was built in 1959.

John

 

[Don McCombs]

It's called efflorescence. Check out this explanation...

https://www.nitterhousemasonry.com/tips ... orescence/

 

[john2189]

Thanks Don. These are inside walls. We will clean it up

 

[Don McCombs]

A sealer may keep it from re-appearing.

 

[john2189]

Thanks