Ceiling Box and General Install Questions

[adamflyer]

Hi All,

I just purchased a Green Mountain 60 wood stove to put in my great room and have some first time installer confusion. Attached is a drawing that shows the setup I'm planning on. My questions are as follows:

1. I'm confused about the connection between the DVL and the ceiling support box. The drawing I found in the documentation shows it has some sort of an adapter protruding from the bottom but all the pictures I see of the box for sale I don't. Best I can tell I need the "DLV Adapter (6DVL-ADT) or do I need something else?

2. I assume my transition between DVL pipe and Class A Duratech pipe is at the bottom of the ceiling box via that "DLV Adapter". So then I just need to make sure this junction is at least 8" away from my ceiling per the 8" ceiling clearance spec for the DLV (since the pipe is coming up at an angle vs vertical) or something else. Also does it look like there is enough room in my drawing for the connection to keep this clearance?

3. As far as I can tell by reading the documentation, by using the ceiling support box there is no other structural support for the stove or chimney pipe other than the "DLV Adapter" junction between DVL and Class A pipe at the bottom of the box. Do I really not need any more support for the chimney pipe other than this for less than 5' above the roofline? I guess the roof flashing above and the stove connection below will stabilize it but it seems like it would need more.

4. If there is a more foolproof way of doing the flashing than tucking the uphill side under the ridge cap please say so. Roof penetrations make me nervous.

Of course I'm open to any other critique to my plan. I like to do things correct the first time. Thanks in advance.
-Adam

 

[begreen]

6DVL-ADT is the right ceiling support to DVL adapter. Each section of the DVL stove pipe gets screwed with 3 screws, effectively making it one unit. The one thing to watch is the Damper section. Unfortunately DuraVent only sells this in the adapter instead of offering the option for it to be in a 6" section of regular DVL. The problem is that for many stoves the adapter is not only unnecessary, it's too small at the flue collar leading to a leaky seal. On many stoves, the DVL pipe connects nicely without any adapter to the flue collar on the stove. I ran into this recently and had to remove the damper from the adapter and then put it into a 6" section of DVL.

The chimney is supported by the cathedral ceiling support box. There is no need for additional chimney support if the chimney is less than 5 ft from the roof exit. If greater, then a roof brace must be installed at the 5' level. In this case it doesn't look like that will be necessary.

 

[adamflyer]

6DVL-ADT is the right ceiling support to DVL adapter. Each section of the DVL stove pipe gets screwed with 3 screws, effectively making it one unit. The one thing to watch is the Damper section. Unfortunately DuraVent only sells this in the adapter instead of offering the option for it to be in a 6" section of regular DVL. The problem is that for many stoves the adapter is not only unnecessary, it's too small at the flue collar leading to a leaky seal. On many stoves, the DVL pipe connects nicely without any adapter to the flue collar on the stove. I ran into this recently and had to remove the damper from the adapter and then put it into a 6" section of DVL.

The chimney is supported by the cathedral ceiling support box. There is no need for additional chimney support if the chimney is less than 5 ft from the roof exit. If greater, then a roof brace must be installed at the 5' level. In this case it doesn't look like that will be necessary.

Thank you for the quick reply. I ordered the parts. Can't wait for some good wood heat.

 

[begreen]

I wrote today to DuraVent about getting the damper put in a regular section of 6" DVL from the factory. This should be an easy one for them. Hope they do it.

 

[Chestnutty]

Thanks for posting this question! I was wondering the same too since we are getting ready to install an Ambiance Hipster 20. How much weight does the ceiling support box hold? We have a 10 ft outside chimney that will have 2 roof support brackets so that will sit on the box. The inside stove pipe has a telescoping part since we are installing in a log home and they settle - so the stove pipe is not helping hold up the roof pipe... is that an issue?

 

[begreen]

The ceiling support box is what is carrying the weight. The stove pipe just connects to this in the room, it offers no support.

 

[adamflyer]

I don't remember how much weight it supports but the documentation says what it is. Basically its rated to hold all the pipe I have below and above. My penetration is near the ridge and so my minimum length above the penetration is below the length to require a roof brace. That being said the chimney pipe above the roof is not very sturdy so I bought a brace I'm going to install.

The answer to my original question (others answered as well): 6DVL (Stove pipe) -> 6DVL-ADT (Chimney Adapter) -> 6DT-CS36 (Ceiling Support Box) -> 6DT-__SS (Class A Chimney Pipe) -> 6DT-VS (Chimney Cap). Attached are the parts I used.

I have a standing seam metal roof so a square hole the size of the Ceiling Support Box was cut in my roof sheathing and metal roofing and the top of the chimney box was folded over on top of the roof sheathing and screwed down. I placed the hole such that the uphill side of the metal roof flashing (6DT-F12DSA) was tucked under my metal ridge cap. Additionally the flashing was bent to conform to the standing seams on the sides. Everything ended up layered like shingles. For good measure I still silicone sealed everything but theoretically the only place it could leak is the seal between the storm collar and the chimney pipe which gives me some peace of mind.

I've ran the stove weeks on end this winter and we have been very happy with the setup.

The hearth is a scrap peice of granite countertop I bought from a local granite shop and the rock on the wall came out of my driveway when I cleared my lot before I built the house.

 

[stoveliker]

I thought code required also screwing the two sections of telescoping pipe together?
(Obviously taking out the screws when one disassembled.)

This would then still be problematic for a settling cabin.

 

[Chestnutty]

I thought code required also screwing the two sections of telescoping pipe together?
(Obviously taking out the screws when one disassembled.)

This would then still be problematic for a settling cabin.

The way we are going to approach this is that the home will settle for about a year. During this time, we will check the screws frequently and loosen and re-tighten them. The stove is not going to be used until winter so we can also leave the screws off until then. Most of the settling should have happened by then.

 

[stoveliker]

I see.
If it is only for a limited time, I'd not screw the overlapping sections down, as any movement would require to drill new holes. You might end up with a sieve...

 

[begreen]

I thought code required also screwing the two sections of telescoping pipe together?
(Obviously taking out the screws when one disassembled.)

This would then still be problematic for a settling cabin.

Hope not. I haven't seen that one. Our last telescoping pipe was screwed together there. It creates a burr on the pipe that scratches the paint badly every time the the pipe is lifted. I didn't screw together the replacement at that joint.