reducing stove pipe size

[cyclone]

Due to the wrong size clay crock/thimble is it possible or not recommended to reduce the stove pipe.

I would be running a six inch stove pipe from the stove with a 90 degree elbow and somewhere at that point have a reducer with 5 inch stove pip that will run to near back of the chimney.

Reason for this is wrong size clay thimble into wall and chimney. To big of a job to take out and a chance of cracking the clay flues in the chimney of where the thimble is mortored.

 

[cyclone]

It is to reduce the stove pipe.


The chimney is about 25 to 30 feet tall. It is masonary and has 6inch clay flu's. They are rectangular flu's and even though I mention 6 inches thay are bigger.

Draft is good.

 

[stoveguy13]

it does not meet code for one two you may get some puff backs and smoke spillage into the house it is not the right way to do it change the thimble to a six inch.

 

[PunKid8888]

I had a similar problem. here is what to do.

Assuming your clay thimble is 5 inchs or larger, and I think it is rectangular in shape and you have single wall pipe. You should be able to take your 6inch pipe and force it from a round shape to a more rectangular shape.

The perimeter of 6inch pipe is 18.85" and the perimeter of a 5x5 square is 20. so in theory it will work, but obviously this does not take into account the radii.

I was able to stuff an 7inch pipe through my 6.5" by 6.5" clay thimble. I used four 1x3 studs and then strapped them around the pipe (make sure one lines up with the seam) and I then just kept pressing it by hand until it was a more square shape. I was able to slide the pipe all the way in the thimble, and I did not square the full length of pipe, the last foot transitions from the square to round so that is still easily connects to the other pipes.

 

[Todd]

My crock has a similar problem but mine was 8" going into a smaller square opening and like Punkidd I just squared the one end of pipe to make it fit.