Question on roof penetration in a shed / non-lovjng area

[Paradigm11]

Hello,

I'm putting a chimney in a workshop / shed. I picked up a ceiling kit from Lowe's and called our fire chief and he just said to follow the manufacturer specifications.

However, the specs are all assuming a dwelling and sound like they have conflicting requirements.

I've got insulated double wide pipe that is passing through a very simple roof of plywood and galvanized metal.

The instructions say I need a 2" clearance from combustibles, which I plan to exceed to around 8" just because it doesn't really matter and better safe than sorry.

My only question is that the kit says you need rafter shielding to penetrate the roof. Do I actually need that? The kit only came with an attic insulation shield and the ceiling support.

I'm really trying to avoid spending a bunch of money getting another piece because I suspect the only real code requirements I need for this is just combustibles clearance and I have that in spades.

This is the fifth place I've asked this same question and I've yet to get a single response, so here's hoping.

Edit: forgot to add, the roof is a 3 : 12 pitch lean-to style if that matters.

 

[bholler]

The only answer we can give is follow the manufacturers instructions.

 

[begreen]

There are multiple types of ceiling kits. Which ceiling kit is this?

 

[kborndale]

Hello,

I'm putting a chimney in a workshop / shed. I picked up a ceiling kit from Lowe's and called our fire chief and he just said to follow the manufacturer specifications.

However, the specs are all assuming a dwelling and sound like they have conflicting requirements.

I've got insulated double wide pipe that is passing through a very simple roof of plywood and galvanized metal.

The instructions say I need a 2" clearance from combustibles, which I plan to exceed to around 8" just because it doesn't really matter and better safe than sorry.

My only question is that the kit says you need rafter shielding to penetrate the roof. Do I actually need that? The kit only came with an attic insulation shield and the ceiling support.

I'm really trying to avoid spending a bunch of money getting another piece because I suspect the only real code requirements I need for this is just combustibles clearance and I have that in spades.

This is the fifth place I've asked this same question and I've yet to get a single response, so here's hoping.

Edit: forgot to add, the roof is a 3 : 12 pitch lean-to style if that matters.

One code requirement that you may have trouble with is the one that states that wood stoves are not permitted in garage/workshop.

 

[Paradigm11]

The kit in question is this one:

https://www.lowes.com/pd/SuperVent-5-Piece-Chimney-Pipe-Accessory-Kit-for-Ceiling-Support/3134415

I understand the framing, flashing, clearance, storm collar, etc stuff. The only thing that's giving me confusion is what the actual requirements are for roof penetration, and since I'm confused I'm unable to follow the manufacturer instructions.

There's no chance in hell that fire code requires a specific piece of hardware from a specific kit. I'm trying to understand what constitutes the actual requirements for shielding the passage between the ceiling and the exterior.

I appreciate the responses!

Edit: Missed a reply while I was commenting. I talked to my town's fire chief and he said the only requirements were to meet the clearances required by the manufacturer and I cannot store accelerants inside of the structure.

 

[begreen]

The kit in question is this one:

https://www.lowes.com/pd/SuperVent-5-Piece-Chimney-Pipe-Accessory-Kit-for-Ceiling-Support/3134415

I understand the framing, flashing, clearance, storm collar, etc stuff. The only thing that's giving me confusion is what the actual requirements are for roof penetration, and since I'm confused I'm unable to follow the manufacturer instructions.

There's no chance in hell that fire code requires a specific piece of hardware from a specific kit. I'm trying to understand what constitutes the actual requirements for shielding the passage between the ceiling and the exterior.

Edit: Missed a reply while I was commenting. I talked to my town's fire chief and he said the only requirements were to meet the clearances required by the manufacturer and I cannot store accelerants inside of the structure.

This may be the wrong kit for the installation. It's a ceiling mount kit. Is there a real ceiling or is the ceiling actually the underside of the roof? Pictures are always welcome.

 

[bholler]

One code requirement that you may have trouble with is the one that states that wood stoves are not permitted in garage/workshop.

National code is only for garages. Workshops vary by state and municipality

 

[bholler]

The kit in question is this one:

https://www.lowes.com/pd/SuperVent-5-Piece-Chimney-Pipe-Accessory-Kit-for-Ceiling-Support/3134415

I understand the framing, flashing, clearance, storm collar, etc stuff. The only thing that's giving me confusion is what the actual requirements are for roof penetration, and since I'm confused I'm unable to follow the manufacturer instructions.

There's no chance in hell that fire code requires a specific piece of hardware from a specific kit. I'm trying to understand what constitutes the actual requirements for shielding the passage between the ceiling and the exterior.

I appreciate the responses!

Edit: Missed a reply while I was commenting. I talked to my town's fire chief and he said the only requirements were to meet the clearances required by the manufacturer and I cannot store accelerants inside of the structure.

The code requirements concerning prefab ul listed chimney systems are that you follow all manufacturers instructions

 

[begreen]

National code is only for garages. Workshops vary by state and municipality

And by usage? I was thinking a metal shop might be different than for a wood shop as long a solvents and rags were kept properly stored and disposed of.

 

[bholler]

And by usage? I was thinking a metal shop might be different than for a wood shop as long a solvents and rags were kept properly stored and disposed of.

Absolutely. Which is why the local code office is really the only one that can say in that regard. Nationally we know garages are out though

 

[Paradigm11]

This may be the wrong kit for the installation. It's a ceiling mount kit. Is there a real ceiling or is the ceiling actually the underside of the roof? Pictures are always welcome.

Underside of the roof. I'm still building it and need to add additional framing among other things, but here are a couple pics:

The pics are roughly where the stove will go, the second is the roof it's penetrating, the final is the kit I have. While it says "ceiling support kit" it comes with the exterior bits like flashing, storm collar and rain cap, which makes my confusion even deeper. If it didn't have what I need to go through the roof why would the kit have the parts for an attic and the exterior but not the final pass through?

 

[bholler]

Underside of the roof. I'm still building it and need to add additional framing among other things, but here are a couple pics:
View attachment 316963
View attachment 316964

View attachment 316962

The pics are roughly where the stove will go, the second is the roof it's penetrating, the final is the kit I have. While it says "ceiling support kit" it comes with the exterior bits like flashing, storm collar and rain cap, which makes my confusion even deeper. If it didn't have what I need to go through the roof why would the kit have the parts for an attic and the exterior but not the final pass through?

It comes with a flat ceiling support box. You don't have a flat ceiling though

 

[Paradigm11]

It's a bit of a misnomer. The flat ceiling support box covers my roof. It supports 0:12 to 6:12, above 6:12 is a different kit.

 

[gthomas785]

I have to assume the rafter shield is for passing within 2" of a rafter? Otherwise you shouldn't need a shield if the wood framing is more than 2" away from the pipe. Can you quote the part of the instructions that says you need rafter shielding?

 

[Paradigm11]

I have to assume the rafter shield is for passing within 2" of a rafter? Otherwise you shouldn't need a shield if the wood framing is more than 2" away from the pipe. Can you quote the part of the instructions that says you need rafter shielding?

It's not getting even near that close, I'm just trying to make extra sure I'm doing it correctly.

Here's the quote:

"Rafter Radiation Shield: Required when the chimney is enclosed immediately below the roof"

And:

RAFTER RADIATION SHIELD:
A Rafter Radiation Shield (RRS) must be installed where the chimney is
enclosed immediately below the roof line as shown in
figure 18. An example of this is when the attic space of a house is being
used as living space (ie. bedroom, guestroom etc.). It must also be
installed when height restrictions will not allow the use of the Attic
Insulation Shield (AIS) and the chimney has been enclosed with an
enclosure around the chimney.

 

[gthomas785]

Key word: enclosed.
The chimney is not enclosed immediately below the roof so you're good.

 

[begreen]

It's the wrong kit. It has parts that you don't need like the attic insulation shield (rafter radiation shield) and the wrong type of chimney pipe support. There's no point in paying for that. I'd return it.

A cathedral ceiling support kit would work. It's something like this. Weirdly, this kit does not include the roof flashing and storm collar so that has to be added. Another alternative would be to get a roof mount support along with the flashing, storm collar, cap, and stove pipe adapter.

FWIW, this is why I never buy this stuff from a big box store. They mix brands and don't have the full line of parts needed to do the job correctly.

https://www.lowes.com/pd/SuperVent-8-Piece-Chimney-Pipe-Accessory-Kit-for-Ceiling-Support/3572826