Hey y’all,

I have to fill about a 10″ diameter hole in an 8″ block wall that used to have a flue pipe to a woodstove going through it.  What type of mortar/concrete product should I use that won’t fall out of the hole as I’m putting it in and won’t sag while drying? 

One thought I had was that on the inside the walls will be covered in closed cell foam.  I could make a wire mesh ball and stick it in the hole.  On the inside the foam will hold the mesh in place and then I could fill it from the outside but my question is still what I should use that will stick to the wire mesh well enough to maybe fill it in one shot. Or will I have to build it up with a couple of coats of something.

Thanks for your responses!