Ashford 25 install - problem bending the flex liner

[ashford55]

Im trying to install an ashford 25. I lined my chimeny with rigid insulated duraliner for the top 19 feet and the last 3 feet Im using flex duraliner. The problem is the stove exhaust is on a 32 degree angle and Im finding out the hard way that the flex pipe doesn't really flex. I was expecting to connect it to the flue adapter and when I pushed my stove back it would just bend in to place. Instead whats happening is the flex is staying rigid and the sheet metal screws Im using are tearing through the liner. I snuck my phone back there were there is still another 2-3" to go and you can see the back is popped out. I also took a picture looking up the damper and you see the tear marks in the liner where the screw went right through.

Ideally Id use a 30 degree elbow but I dont have the clearance....the duraliner elbows stick out 4" before making a bend and Im already real close to the back of my firebox. My next plan was to get rid of the adapter at the end of the duraliner flex and put the flex directly in the blazeking flue adapter. Then I would use bolts and washers instead of sheet metal screws in the hope that the washers would pin the flex in place and it wouldnt tear.

Wondering if there are any other options here? I know the offset adapter is a possibility to get enough clearance for an elbow but I was hoping to avoid using one since I was afraid it would making cleaning from the bottom harder. Is there an approach to gently pre-bend the liner?

 

[bholler]

Im trying to install an ashford 25. I lined my chimeny with rigid insulated duraliner for the top 19 feet and the last 3 feet Im using flex duraliner. The problem is the stove exhaust is on a 32 degree angle and Im finding out the hard way that the flex pipe doesn't really flex. I was expecting to connect it to the flue adapter and when I pushed my stove back it would just bend in to place. Instead whats happening is the flex is staying rigid and the sheet metal screws Im using are tearing through the liner. I snuck my phone back there were there is still another 2-3" to go and you can see the back is popped out. I also took a picture looking up the damper and you see the tear marks in the liner where the screw went right through.

Ideally Id use a 30 degree elbow but I dont have the clearance....the duraliner elbows stick out 4" before making a bend and Im already real close to the back of my firebox. My next plan was to get rid of the adapter at the end of the duraliner flex and put the flex directly in the blazeking flue adapter. Then I would use bolts and washers instead of sheet metal screws in the hope that the washers would pin the flex in place and it wouldnt tear.

Wondering if there are any other options here? I know the offset adapter is a possibility to get enough clearance for an elbow but I was hoping to avoid using one since I was afraid it would making cleaning from the bottom harder. Is there an approach to gently pre-bend the liner?

Remove some brick and use an elbow

 

[spudman99]

In my recent Princess Insert install I removed the top 2 bricks from the back of the fireplace, along with cutting out the metal part of the damper. When the liner came down the chimney it made a natural 30 deg angle towards the insert.



I then measured about 10 times where the bottom of the appliance connector would meet the BK and cut the liner. Went in just about perfect. In the photo you can see the liner and its natural bend, I already have the block off plate and roxul in the rear.

 

[ashford55]

In my recent Princess Insert install I removed the top 2 bricks from the back of the fireplace, along with cutting out the metal part of the damper. When the liner came down the chimney it made a natural 30 deg angle towards the insert.

View attachment 251208

I then measured about 10 times where the bottom of the appliance connector would meet the BK and cut the liner. Went in just about perfect. In the photo you can see the liner and its natural bend, I already have the block off plate and roxul in the rear.

Ah nice. In my case I've already taken out my damper frame and top two bricks to get the liner to come down straight. I guess I have an aggressive smoke shelf...I suppose I could just keep removing more bricks.

 

[ashford55]

If Im removing a good chunk of the firebricks from the back wall, is there any concern with too much heat making it to the outside of the fireplace? The bricks Im removing would be on the sloped part of the wall so I imagine there should still be enough cement/bricks between that and the outside that it would be fine?

 

[mellow]

I wouldn't remove anymore than a couple bricks unless you are certain of your chimney structure will still support the weight with more being removed. That is a heck of a tight fit to the back wall. My thought is can you add more bricks to the fireplace front so you can space that thing out more from the back and not have it look funny sticking out from the wall. Maybe mortar some cultured rock veneer to the front bricks?

Then you could insulate that back wall and keep the heat in.

 

[bholler]

I wouldn't remove anymore than a couple bricks unless you are certain of your chimney structure will still support the weight with more being removed. That is a heck of a tight fit to the back wall. My thought is can you add more bricks to the fireplace front so you can space that thing out more from the back and not have it look funny sticking out from the wall. Maybe mortar some cultured rock to the bricks?

Then you could insulate that back wall and keep the heat in.

It is the firebox wall not the chimney wall it is not structural

 

[ashford55]

I wouldn't remove anymore than a couple bricks unless you are certain of your chimney structure will still support the weight with more being removed. That is a heck of a tight fit to the back wall. My thought is can you add more bricks to the fireplace front so you can space that thing out more from the back and not have it look funny sticking out from the wall. Maybe mortar some cultured rock to the bricks?

Then you could insulate that back wall and keep the heat in.

Well to be clear Im just talking about removing firebricks, I didn't think those were structural?

Unfortunately there is no way I can have this thing stick out. I don't have a hearth at all, its a brick wall with the opening in the center of the wall.

 

[bholler]

If Im removing a good chunk of the firebricks from the back wall, is there any concern with too much heat making it to the outside of the fireplace? The bricks Im removing would be on the sloped part of the wall so I imagine there should still be enough cement/bricks between that and the outside that it would be fine?

What is on the back side of the fireplace?

 

[ashford55]

What is on the back side of the fireplace?

Its an external chimney.

 

[bholler]

Its an external chimney.

Then nothing to worry about other than heatloss. And an extra layer of brick would do almost nothing to change that

 

[ashford55]

Then nothing to worry about other than heatloss. And an extra layer of brick would do almost nothing to change that

Great thanks

 

[spudman99]

If you have space behind the insert, you can install some roxul insulation between that and the brick. Insulation will help retain heat inside the house. You can see that in my picture above in post #3 but I also had about 6 in of space behind the insert and the rear wall. I only needed to knock out the top row of fire bricks to give me an 8 1/2 inch gap for the liner.