Duraplus cathedral ceiling supply box install.

[Bingo]

hi all,
I'm am going to be installing a duraplus cathedral ceiling support box, I've been looking at the instruction manual and have a few questions. It says in the instructions to snip the corners of the part of the box that extends through the roof and fold it down and nail to roof or framing. My question is do I have to fold it over and nail it to the roof or can I nailii to just the framing between the joists. The only pic in the manual shows the sides being folded over the roof. I'd prefer to just nail it to the framing to avoid having to remove and replace shingles. My second question is if I have to nail it to the roof, do all four side have to be folded over or can it just be 3 sides, and can I trim off some excess and just leave a few inches to fold over and nail?

 

[begreen]

You can box it in and just nail it to the framing with the top edge trimmed flush with the roof. Just be sure to use 3 screws per side for good support.

 

[xman23]

It holds up the all the weight of all the chimney above, so secure it well on all sides.

 

[Bingo]

Thx a lot guys, much appreciated.

 

[Bingo]

@begreen the manual says I should use 8 penny nails. You mentioned using screws, Do you prefer screws over nails for any particular reason? Thanks.

 

[begreen]

The DuraVent manual goes into a bit more detail. There they say:
"and nail the Support Box to the roof or framing with at least three (3) 8-penny nails, or (3) 1-1/2", #8 screws, per side (Fig 20)."
I like screws because they are less likely to work loose with continued vibration.

 

[Highbeam]

Get the dang thing screwed in perfectly level. The plumbness of your chimney depends on it. I too use screws. Easier to remove if you screwed up on level.