Cleaning Masonry

[Garrin]

Howdy All,

I've got a multi-flue cap that, with the slow and low burns, gets a lot of black drippy goop coming down.

Any good way to clean this off? I know the guy who build the chimney put some sort of sealer on the whiteish cap, but I'd have to reach out to him to see exactly what it was.

Thanks for any suggestions in advance!