BKK flue hook-up?

[Jon BK]

Getting close to finishing the BKK alcove build and hook-up. Using Majestic SK-8 double-wall pipe. The 12" length section you see in the picture is 4" too short. The 18" section I have coming in will be 2" too long so I plan on carefully trimming 2" away with tin snips. You can also notice that the OD/ID of my inner 8" wall is the same as the BKK flue outlet.

1.) Height - Is my trimming technique a good idea? Unfortunately Majestic / Monessen does not make telescoping parts. I have 2.5" of stove flue outlet height, and about 1" of vertical play if I push up on the entire chimney.

2.) Diameter/Fit - Is it ok to cut two short vertical slits in the 8" inner pipe to allow fit over the flue outlet? My goal is to have this slit completely pushed down over the outlet so there is no air gap, but I am not sure if this is realistic.

The 18" part should arrive today. All side (10"), rear (6"), and height (49") clearances are met using the rear and side shields. Thanks for your help! - Jon

 

[begreen]

Welcome to hearth.com. Are you sure that the old SK-8 fireplace pipe is UL103HT 2100 rated as required for the stove? SK-8 is normally a fireplace pipe rated at 1700F. It is not designed to couple with a standard stove. Check with Blaze King and Majestic.

 

[Heatsource]

the sk pipe is Definitely not rated for you BKK

sorry for the bad news, but you will need all new pipe

 

[Heatsource]

it doesn't look like you have the 20" side clearance as required by the maker either..

 

[jeff_t]

it doesn't look like you have the 20" side clearance as required by the maker either..

It's 9" for alcove. Side shields required.

That pipe appears to be made for Majestic/Monessen fireplaces only.

 

[Heatsource]

It's 9" for alcove. Side shields required.

That pipe appears to be made for Majestic/Monessen fireplaces only.

oops, i was looking at c measurement...

 

[jeff_t]

For whatever reason, it's 9" in an alcove, but 10" out in the open?

 

[Jon BK]

Thanks for the feedback. I had a hunch this may be the case, but looked past that so far as the Majestic was double walled, UL rated, and in a modern (2005) build for the old cheap insert.

From my understanding most double walled stove pipes have the 1000F gas outlet capabilities, but the difference in safety ratings for chimney fires. The old Majestic pipe would fare worse in a chimney fire correct? It seems odd that it is safe for an insert but not a stove; is there a different probability or temperature in chimney fire situations? Are there any other special characteristics of the Majestic fireplace that allows for a less robust flue? From burning the insert last year, the flames easily went into the bottom of the flue directly which seems riskier than a well built CAT stove. Perhaps the CAT stove becomes hotter overall than the open faced insert could achieve.

Will a Duravent or similar UL103HT pipe hook directly over the BKK flue outlet, or is there a separate adaptor?
For height fine tuning, I assume everyone has a telescoping piece under the attic support? Or is it more common to couple the pipe to the attic support once the required height is known and set? That would seem more of a hassle for removal for sweeping purposes.

 

[jeff_t]

The Majestic pipe is designed and tested for the Majestic/Monessen products only. Will it work in your application? Maybe, but it's your and your family's safety, and any inspector should not sign off on it. If anything bad were to happen, your insurance company could deny any claims.

Class A chimney pipe should stop at the support, and use black connector pipe, preferably double wall, between the stove and ceiling. Duravent, Selkirk, Excel, to name a few. They all have the necessary adapters to make it work. Telescoping connectors make cleaning much easier.

 

[webby3650]

The insert you are referring to is a pre-fabricated fireplace, not an insert. Just trying to prevent confusion here. They are made as cheap as possible, don't expect the pipe that's made specifically for these to be any better. The difference is its made for the small open fireplace that is sucking 200 cubic feet of air out of your house along wh the smoke. The flue gasses are much cooler than a stove is capable of. These fireplaces also have no ability to reduce the air, preventing a smoldering fire that causes creosote build up. Therefore, a flue fire would be much less intense if it was able to happen.

Does this pipe go all the way out to daylight?

 

[Jon BK]

Good point, it was a pre-fab fireplace. The oak surround probably cost more than the fireplace. Without the fire brick it only weighed about 60lb! It truly did suck a ton of air, burn a ton of splits, and had no control. The OAK had a damper control, but it still was worthless for heating overall. It makes sense that the flue gassed would be much cooler in a pre-fab compared to a hot stove, and that relates to creosete fire risk.

Yes, the pipe is 15' up to daylight, through a frame and siding chase. It has the Majestic brand attic support, insulation shield, and flue termination. The dampener was built into the top of the prefab.

I will have to be careful with the pipe design for the refit with Class A to black connector pipe. I don't have 18" of clearance on the back of the alcove, there are wood studs behind the airstone and fire rock. It looks like there are telescoping double wall options, as well as 30* offset double wall options that I also need.

 

[jeff_t]

Double wall connector, recommended for the BK because of already low flue temps, needs only 6" clearance to combustibles.

 

[webby3650]

Changing it all out isn't that big of a deal really. With telescoping sections of pipe you will most likely be able to hit the flue collar even with the 45's. Different brands have different amounts of offset. For example Dura-Vent DVL have a 5" offset with elbows back to back, where ameri-vent has a 7" offset.

 

[Jon BK]

Thanks for the feedback again guys! With the new 18" section of SK8 it is clear this isn't going to work. I will scrap the Majestic SK8 system, without even getting to break in the BKK!

DuraTech quoted out $1872 on Woodland Direct, yikes. Excel is even more, as is Champion. Selkirk seemed similar until I went to Menards like Jeff recommended in this post: https://www.hearth.com/talk/threads/blaze-king-to-selkirk-dsp.129798/
That is a more reasonable $1100.

My confusion is around the Supervent Class A to double wall pipe adaptor. This seems to be the correct part - Selkirk Double Wall Stove Pipe 8" Universal Chimney Adapter, DSP8CA. However it does not indicate what type of stove pipe it adapts and Selkirk has several different ones. The buyer guide seems to indicate this will work but isn't very specific.

Also I will be running the Supervent down through my chase (only 4" clearance front and back), through a 30deg offset kit, and then intend to adapt to the double wall stove pipe. Will this be possible? All the reference diagrams show the adaptor directly on the ceiling support.

Thanks for your help!

Jon

 

[jeff_t]

JSC8ASE is the part you use to adapt the chimney to connector. It twists on the bottom section of chimney pipe, then sits down in the ceiling support.

DSP8SA-1 adapts the double wall connector to the flue outlet of your stove.

 

[webby3650]

If you use a cathedral ceiling support, the class A pipe passes through the box and into the room as much as needed. It comes in very handy sometimes because of close clearances. In this case the adaptor goes in the end if the class A.