new flu hole ?

What is the easiest way to cut a flu hole in an existing cement block chimney with a clay liner ? I can drill 1/2 inch or so holes around the outside circumference and chip out the cement block, but what about the clay liner? I don't want to break or crack that.

Depends concrete contractors with a big wet core drill will make a very nice hole...
12" hole for me was $250 most of the cost is the setup, drilling and travel time...
Not the size of the hole...

I was hopeing I could get diamond wheel for a small hand grinder and rough it out with that .

If you take your time you should be fine my friend.

I like the multiple hole method, and with a nice small 'Bosch or equal' hammer drill, I'd go with 3/8" bits and make it quick and easy. Not a job to play 'Magilla the Gorilla' on, slow and steady wins every time.

Make the hole big enough the first time for a thimble of appropriate size.

Here is a PS: leave the damned thimble out a 1/4 to 1/2" when you are done. You need to screw the stove pipe into it in at least three places, so give yourself some room to do just that.

Sure, I'd love to 'core' every hole, but this way you won't spend $20.00 on two SDS bits and a 25.00 rental of a small hammer drill.

I have not used a small diameter diamond wheel myself, but if you go that route, let us know how it worked. (Hard to make a round hole uniform, IMO)

Yep, mine was thru 8" poured concrete...
Block would be way easier to do oneself...

Poured is NO QUESTION: Call the Coring Boys.....you would not live long enough! Block.....not so much work.....

Raining HARD right now...thought it was only a 20% chance tonight....oh well.....

Clear and dark?
Big rain sunday-tuesday...
Pumps are ready...

Thanks for the info , I do know a retired mason who doesn't live to far from me ,so I just might stop over to his place in a few days and see what he suggests. Who knows ,maybe he will lend me the right equipment or at least some more ideas.

CapeCoaler wrote:Clear and dark?
Big rain sunday-tuesday...
Pumps are ready...

It is looking like a major snow storm for N. PA and NY Monday. Trees leafed out + heavy wet snow of maybe a foot or more = bad start to the week!!