Center Mount Roof Jack

[concord maple]

I am in the process of having my first sugar house built and was wondering what size of center mount roof jack is needed if my stack on the evaporator is 6" in diameter? Also, how big of hole do I need in the roof to maintain distance from the roof wood to the stack in the jack?

[WESTVIRGINIAMAPLER]

I have a Leader 10" center mount roof jack and really like the design of it due to the fact that it is aprox 11" at the bottom and tapers down to 10" at the top where it has a male crimp. This allows you air space around the bottom of the jack but a nice watertight seal at the top as it is aprox 3' high and I have another section of 3' stainless 10" pipe on the top.

[MapleME]

I think you need one size up so you have good clearance on all sides. at least 1/2 to 1" all the way around

[Russell Lampron]

I have an 8" pipe on my evaporator and an 11" pipe through the roof jack. This leaves a 1.5" air gap around the 8" pipe. Check your local building codes, you will probably need 18" of space between your roof jack pipe and the rafters.

[maple flats]

If you have single wall stack pipe with no insulation you need 36" clearance to wood. For each 1" spaced metal you cut that by half. I have a 12" stack with 3 layer spaced aorond it. I went 36"/2=18, 18/2=9 and 9/2=4.5" I kept my space at 5" from the outer layer, that way. Another way is to use ceramic insulation or other non flamable insulation, however I do not know a formula for the insulation method. The space one i stated is industry standard for wood fired and is adopted as most state fire codes. If you want to be covered by insurance as I did you likely will need an inspection by some authority, mine had to be by our local fire dept. I made my triple wall cover by taking light gage stack pipe and seperating them with 1" metal spacers I formed and pop riveted in place. For mine I used a 14", 16" (really 2 8's hooked together) and a 20" (2x10", because I could not find 9") If I do it again I plan to just use 30 ga flat sheets of sheet metal and rivot them into a circle, I think they will stay rounder that way as opposed to joining 2 to form a larger one, they do not stay very round that way. Now for the final size for my 12", my outer pipe layer is 20 and my opening is 30", 5" on each side I made that truss space 32" on center which is 30" inside while all the others are 24") Your roof jack should then be wide enough to flash over the hole and attach to the roof boards or trusses.

[WESTVIRGINIAMAPLER]

My rafters are on 2' centers and I have a 10" stainless stack going between 2 of them and it is single wall, so I only have aprox 6" clearance on each side. I have all the wood within several feet covered with 1" ceramic blanket and it works great and I don't think I would ever have any problems with it.