Bricks, Masonry, Asphalt and Concrete - chimney crown repair

Hi,
I have 2 terracotta type flue's protruding from my chimney (one for the fireplace and the other for the central heating system). I am located in massachusetts.

The two flues are about 1 inch apart. In the gap between them where they meet the crown, no mortar exists. So there is about a 1 inch by 8 inch opening in the crown of my chimney in between the two flues.

How should i fix this? Any help would be greatly appreciated, especially as the cold months near.

thanks
Andy

Mix 1 portland cement and 2 parts sand and water just enough to make it like peanut butter, and fill in the crack, you can use a stick to push it in and smooth it out.
Frank

You want to build it up a little higher there with the new cement . So any rain water runs out of there.

thanks guys. i'll do that.

I do have a question though. It seems like the gap is maybe a little large and i fear that the cement will just fall down the gap. Can i bridge the gap with something then cement over that?

cheers
and thanks for the quick response
Andy

You could like jam some fiberglass insulation down in it some. Then cement over it