Chase or no chase? I'm installing a BK Ashford 30. Elevation just under 6000'

[bobanne]

The stove will be installed in a new addition, so effectively new construction. We are also putting on a new roof at the same time.

Blaze King recommends a chase in their owner's manual, but the retailer says no one does that with the new insulated chimneys unless it's for asthetics.

I want to make sure we have the right draft. We will have the recommended 17' chimney running straight up from the stove.

Chimney will be ICC "Excel" (icc-chimney.com).

What do you all think?

@BKVP @begreen @stoveliker @Highbeam

 

[stoveliker]

A chase does add some insulation from Wyoming cold winters.
It may not be needed, but it surely will not hurt things. I don't know enough about chimney pipe brands to comment further on that and will leave it to others.

17 ft straight up sounds nice - but what is the elevation above sea level of your home? (apologies if I asked this before in another thread...)
Elevation decreases draft. BK advises to add a foot of chimney height per every 2000 ft elevation I believe.

 

[Woody Stover]

That 6000' will take at least a couple feet off the effective height of the stack. That might be pushing it with a BK.
Is the older section of the house taller/upwind of the prevailing winds, where a down-draft on the chimney might be created?

 

[stoveliker]

Yes BK suggests 18 ft minimum for that elevation.

 

[bobanne]

That 6000' will take at least a couple feet off the effective height of the stack. That might be pushing it with a BK.
Is the older section of the house taller/upwind of the prevailing winds, where a down-draft on the chimney might be created

@stoveliker
Thanks to both of you. 18' puts us 6' above the peak of the roof, I guess if we do a chase that would cover the need for a brace. Otherwise do know of guidelines for how to brace a chimney that is so far above the roof? I read through this thread: https://www.hearth.com/talk/threads/bracing-a-tall-chimney-to-roof.165630/#google_vignette

We are doing a new roof at the same time as the chimney install, could you give me some guidance @Hogwildz ?

It's dark out, but I can post photos tomorrow.

 

[stoveliker]

A chimney pipe needs a brace every 5 ft above the roof penetration.
A chase would obviate that need.

Are there snow loads sliding down that may be a concern? Both chase and pipe might need protection from that.

 

[Highbeam]

With that chase you have to deal with the snow running into it, so you'd need a little cricket or whatever they call that thing that attempts to help water run around a big box chimney. I'd stick with a regular pipe and use a brace if you are over 5 feet above the roof deck.

 

[bobanne]

With that chase you have to deal with the snow running into it, so you'd need a little cricket or whatever they call that thing that attempts to help water run around a big box chimney. I'd stick with a regular pipe and use a brace if you are over 5 feet above the roof deck.

Thanks Highbeam and @stoveliker. I think we will start with just the chimney and support, we can add a chase later if the draft needs help.

 

[Highbeam]

Thanks Highbeam and @stoveliker. I think we will start with just the chimney and support, we can add a chase later if the draft needs help.

I don't live in Wyoming, yet, but I would not want the roof leaks and maintenance associated with a chase like that compared to the ease of properly installing a pipe penetration. Roofers have a hard time flashing square chimneys. They always seem to have wood rot around them.