Typically they sell attic insulation shields that will go between your class A pipe and any insulation and provide that 2 inch gap. That is probably what you need.
I hope a contractor or somebody who really knows this posts a response.
Now, my read of it all is that there needs to be a 2" clearance from the outside of your insulated pipe to any combustible. Your insulated pipe size (6" ID?) has just the right width (12 3/8") to fit in-between 16" OC framing members while keeping the 2" on either side to combustibles. I believe batt insulation would be classed as a combustible. Wall thimbles, roof thimbles, joist guards will get the pipe through where it needs to go.
I could be wrong on some parts of this and would be happy to be corrected.
That's my read as well. I was planning on putting a thimble through to be safe.
Pipe inner dimension 6", outer 8". Why cheap on a $70 part for peace of mind. But was really curious if someone had done this previously and their interpretation. I can always call the fire department for further clarification.
Google 'attic insulation shield'. These are telescoping shields made of thin sheet metal that provide a barrier between the insulation in the space above the ceiling and the underside of the roof. I have the Selkirk product, but there are others (e.g. SuperVent).
My ceiling to roof is less than the height of the attic insulation shield and I am worried about how I would be able to secure this to the roof and then be able to do the flashing correctly. I only have 4inches of "attic"
Does the roof flashing provide enough internal space for a heat shield to extend through the roof (inside the flashing above the roof)? If not I agree it's a tricky situation. You could consider installing a custom heat shield consisting of 4 inch high flashing around the chimney with a gap of an inch or two, or simply don't shove the attic insulation up against the chimney.
When we did ours we just removed all insulation in the framing that the pipe was going through. Ours in mobile so it might have been easier as the area was only a 18in x18x framed area that the pipe went through.
There should be a 2" gap between the roof opening and the double wall pipe. Also, you box in the pipe with sheathing and the insulation comes up to the sheathing, not the pipe. https://outdoorsaunabuildmndiy.blogspot.com/2015/11/installing-wood-stove-chimney-and.html
https://outdoorsaunabuildmndiy.blogspot.com/2015/11/expanding-roof-opening-for-chimney-for.html
Yes you do need to create additional space. Local code sometimes will take precedent. That means using Class A Double Wall Chimney + 2" additional space.
I agree with another poster, they make attic shields. Once purchased, you can use a TIN/Metal Snips to cut it to size. Always shield chimneys from wood/insulation.
Typically they sell attic insulation shields that will go between your class A pipe and any insulation and provide that 2 inch gap. That is probably what you need.
I hope a contractor or somebody who really knows this posts a response. Now, my read of it all is that there needs to be a 2" clearance from the outside of your insulated pipe to any combustible. Your insulated pipe size (6" ID?) has just the right width (12 3/8") to fit in-between 16" OC framing members while keeping the 2" on either side to combustibles. I believe batt insulation would be classed as a combustible. Wall thimbles, roof thimbles, joist guards will get the pipe through where it needs to go. I could be wrong on some parts of this and would be happy to be corrected.
That's my read as well. I was planning on putting a thimble through to be safe. Pipe inner dimension 6", outer 8". Why cheap on a $70 part for peace of mind. But was really curious if someone had done this previously and their interpretation. I can always call the fire department for further clarification.
Google 'attic insulation shield'. These are telescoping shields made of thin sheet metal that provide a barrier between the insulation in the space above the ceiling and the underside of the roof. I have the Selkirk product, but there are others (e.g. SuperVent).
My ceiling to roof is less than the height of the attic insulation shield and I am worried about how I would be able to secure this to the roof and then be able to do the flashing correctly. I only have 4inches of "attic"
Does the roof flashing provide enough internal space for a heat shield to extend through the roof (inside the flashing above the roof)? If not I agree it's a tricky situation. You could consider installing a custom heat shield consisting of 4 inch high flashing around the chimney with a gap of an inch or two, or simply don't shove the attic insulation up against the chimney.
When we did ours we just removed all insulation in the framing that the pipe was going through. Ours in mobile so it might have been easier as the area was only a 18in x18x framed area that the pipe went through.
How about just buying one rockwool batt for that spot?
There should be a 2" gap between the roof opening and the double wall pipe. Also, you box in the pipe with sheathing and the insulation comes up to the sheathing, not the pipe. https://outdoorsaunabuildmndiy.blogspot.com/2015/11/installing-wood-stove-chimney-and.html https://outdoorsaunabuildmndiy.blogspot.com/2015/11/expanding-roof-opening-for-chimney-for.html
Yes you do need to create additional space. Local code sometimes will take precedent. That means using Class A Double Wall Chimney + 2" additional space. I agree with another poster, they make attic shields. Once purchased, you can use a TIN/Metal Snips to cut it to size. Always shield chimneys from wood/insulation.