Wall thimbles

[kwdaye]

I am installing an insulated stove pipe through an 8 inch thick poured concrete wall and I was wondering if I need to use a wall thimble. There is no wood or drywall where the pipe goes through the wall. The pipe diameter is 6" I.D. and 8" O.D. and I was wanting to know if I can just core drill a 8" inch hole through the concrete wall and not use a wall thimble?


Thank you,
kwdaye

 

[DriftWood]

Walls poured concrete anwthing on it, paint or covering of any type.

 

[kwdaye]

No, there is nothing on the walls, inside or out.

 

[Metal]

If you don't put in a thimble the concrete will be touching the pipe and the heat will be trapped creating a hot spot. Bad idea.

 

[precaud]

Sounds like an insulated double wall pipe you're using, yes? If so, you'll be fine.

I am installing an insulated stove pipe through an 8 inch thick poured concrete wall and I was wondering if I need to use a wall thimble. There is no wood or drywall where the pipe goes through the wall. The pipe diameter is 6" I.D. and 8" O.D. and I was wanting to know if I can just core drill a 8" inch hole through the concrete wall and not use a wall thimble?
Thank you,
kwdaye

 

[jtp10181]

I believe per code the 2" clearance around Class A is supposed to be an "air space" clearance. At minimum I would core a 10" hole.

 

[kwdaye]

Yes it is double insulated pipe and the the wall thimble hole will have to be 11", I will use the wall thimble just to be safe on to make sure it will pass local code.

Thank for all the responses, they were helpful

kwdaye

 

[Metal]

Even if it is double wall insulated you still need the airspace around the pipe so heat doesn't build up there, you are correct to use the thimble. Maybe you could take post pictures here to help others that may want to do the same thing in the future.

 

[kinsmanstoves]

It would be nice to use some type of sleeve and cement that into the wall. Run the pipe through the sleeve. Check with your local building inspector. Eric