Built hearth pad. Lost on pipe installation w/ cathedral ceiling....HELP!

[michiganwinters]

Drywaller is coming Wen. and we are just scratching our heads on the pipe install. Its a cathedral ceiling with a 4/12 interior pitch and the roof above is I believe, 8/12. These are scissor trusses. So the cathedral attic supports Ive seen are really just a long rectangle box?? Im not sure what to do with it??? Is there a trim ring around it or something? Then I think I will need to use a insulation gard because of how close it is to the outside wall. Im not sure what to do with the flashing. Im sure cut a hold in the roof, then tuck it (the flashing itself) under shingles then what? Do I leave the bottom of the flashing hangin out of the shingles or shingle around it? Does anyone have pics of their class a instal? A view of the roof would be very helpful. We are very very handy but this is kinda stumping us.

Thanks in advance
Audrey

 

[nshif]

Im right in the middle of almost the exact same install. (6:12 inside 8:12 outside ) What brand class A and stove pipe are you using? Im using Simpson. The ceiling support box gets mounted through the ceiling prependicular to the floor so one side hangs down 2" (min ) and the other side hangs down about 4-6" depending on your pitch. this box continues to the roof line and is cut to match that pitch. then your stove pipe hangs down from the bottom of that box and your class A starts from the inside of that box and goes up. above that you will have your flashing which is a large cone shaped piece that fits over the pipe and goes under the shingles with a storm collar around the top of that. On the inside there is a trim piece that goes around the box to finish off the box to the drywall. I might be able to some pics tomorrow of what im doing if I get that far If that will help.

 

[hearthtools]

Cathidral support

support box framing

support box

 

[michiganwinters]

Exactly what I was looking for Im using pipe from Menards called Supervent out of Canada. This helps A TON THANKS!

 

[nshif]

Just make sure the ceiling suuport box extends 2" below the sheetrock on the LOW side. Well thats the spec from Simpson check the spec on your brand. Should be about the same.