Chimney Flu Brace

[ColdNorCal]

I need to brace a newly installed chimney flu. A 7" SS pipe will be insulated and slid over the flex liner. The height from top of brick chimney to top of flex liner is 4 ft. Rather then deal with the tile roof I'd prefer to brace off the 7inch liner to the brick chimney. The flu bracket will be placed 2 1/2 to 3 ft from top of chimney. The braces will be secured with tapcon screws placed in the 2nd and 3rd row of bricks. One brace rod will be on each side of the flu pipe with a third on the front side. The front side of chimney is much longer and has more leverage to hold the flu therefore, three braces total.


Due west of chimney and only 50 ft away is a very long row of 70-90 ft pine trees. I have no idea if this will create a chimney downdraft in certain conditions. If more draft is needed and a 2 ft section is added on, providing a total of 6 ft of flu pipe from top of chimney, will more bracing be required?

 

[begreen]

Some background here
https://www.hearth.com/talk/threads/liner-as-chimney-extension.168599/

 

[webby3650]

Why not just try your stove on the setup like it is? You’ve got 11’6” right? The stove calls for 12’? SBI stoves are easy breathers, I’m betting it’ll be fine.

 

[bholler]

I would do as webby said and if it needs extended do it correctly with a transition anchor plate and class a.

 

[webby3650]

I would do as webby said and if it needs extended do it correctly with a transition anchor plate and class a.

I too have seen several of these single wall flue extensions. They are full of creosote, often to the point they are actually restricting draft, not to mention how dangerous all that fuel is in the event of a flue fire. Typically the rest of the system is pretty clean.
Do it right, with a transition anchor plate and a section of class A pipe. I bet it’s not necessary anyway...

 

[BrotherBart]

On three sides of my chimney are 100 foot trees 50- 80 feet away and downdraft has never happened. And thankfully, yet, none have fallen on the house.

 

[moresnow]

On three sides of my chimney are 100 foot trees 50- 80 feet away and downdraft has never happened. And thankfully, yet, none have fallen on the house.

Same situation here. Draft is no problem. Laying in bed during a high wind event is another story

 

[ColdNorCal]

Why not just try your stove on the setup like it is? You’ve got 11’6” right? The stove calls for 12’? SBI stoves are easy breathers, I’m betting it’ll be fine.

Apologies for any confusion per the prior older thread. From top of stove to top of brick chimney is 11' 6". The total chimney height, from top of stove to top of flex liner extending 4 ft above brick chimney, is 15' 6" but does have an adj 90 set at about 75 degrees and the flex liner makes a nice smooth bend, no horizontal run, that makes the transition from that 75 degree elbow to the vertical run.

Night temps here are rarely below 32 degrees. Typically upper 30's at night and mid 50's during daytime. These warmer temps, not wanting to waste the excess liner, prefer not to make a transition from one type of flu pipe to another, and other reasons are why I decided to put a SS 7" stove pipe over the 4 ft of liner extending beyond the existing brick chimney. If creosote becomes an issue, no problem installing Class A pipe later.

I am interested in thoughts about securing the flu pipe per the first post in this thread.

btw - the 15 ft flex liner was actually 16 ft in length.

 

[bholler]

Apologies for any confusion per the prior older thread. From top of stove to top of brick chimney is 11' 6". The total chimney height, from top of stove to top of flex liner extending 4 ft above brick chimney, is 15' 6" but does have an adj 90 set at about 75 degrees and the flex liner makes a nice smooth bend, no horizontal run, that makes the transition from that 75 degree elbow to the vertical run.

Night temps here are rarely below 32 degrees. Typically upper 30's at night and mid 50's during daytime. These warmer temps, not wanting to waste the excess liner, prefer not to make a transition from one type of flu pipe to another, and other reasons are why I decided to put a SS 7" stove pipe over the 4 ft of liner extending beyond the existing brick chimney. If creosote becomes an issue, no problem installing Class A pipe later.

I am interested in thoughts about securing the flu pipe per the first post in this thread.

btw - the 15 ft flex liner was actually 16 ft in length.

Just use an anchor plate for the 7" no more is needed at 4'

 

[ColdNorCal]

Just use an anchor plate for the 7" no more is needed at 4'

I set 1/4" ss bolts when I rebuilt the chimney crown to secure the flex liner anchor plate. The plate is also siliconed and very secure. Will 4 SS screws at the bottom of the 7 inch flu pipe work to secure the 7 inch pipe to the liners anchor plate? I am a little hesitant on using the flex liner anchor plate alone as its only 24 gauge.

 

[bholler]

I set 1/4" ss bolts when I rebuilt the chimney crown to secure the flex liner anchor plate. The plate is also siliconed and very secure. Will 4 SS screws at the bottom of the 7 inch flu pipe work to secure the 7 inch pipe to the liners anchor plate? I am a little hesitant on using the flex liner anchor plate alone as its only 24 gauge.

You need to bolt down the class a anchor plate. It is much thicker metal

 

[webby3650]

You need to bolt down the class a anchor plate. It is much thicker metal

I think he’s still planning on using single wall though.