Flex Liner Install

[jblood]

Hey all,

I finally pulled the trigger and ordered and received my insert and flex liner. I am putting a Regency CI1200 into a prefab fireplace and will be using a Magnaflex Insulflex SS insulated liner inside a prefab 8" diameter double wall ss chimney. I am looking forward to performing the install but have some final questions regarding the liner:

1. The flex liner at the stove:

The flex liner attaches to the stove adapter via three screws. I had planned to put a bead of furnace cement at this junction. Is that advisable? Will it cause trouble if I need to disassemble for cleaning or does this joint stay intact during cleaning? (The stove manual does not mention furnace cement)

2. The flex liner at the top of the chimney:

The flex liner can be secures with three screws at the top of the chimney? The OD of the flex liner is ~7-1/2" and the ID of the Chimney is ~8". So, there is a small gap around the diameter. Are three screws sufficient or should some sort of adapter be used? Should roxul or something else be used to seal that gap? Speaking of that - does anyone know where I can get a small qty of roxul (fireplace supply etc..) or do I have to special order a giant batt from Lowe's. I literally only need a handfull. Maybe I can scavenge some insulation from the unused cutoff piece of flex liner?

3. Stove

The offset adapter connection to the stove is a tight fit but it is steel to steel. Should I put a bead of furnace cement at this interface also? Again, the manual states nothing about using cement. I want to seal up everything nicely but I also want to make sure that it is serviceable.

I welcome any advice\experience you may offer! I will document the install with photos and post when complete.

 

[glenlloyd]

For my installation I didn't use furnace cement on the liner to appliance adapter connection. The fit is tight and I actually left the insulation and outer aluminum skin in place to cover the top of the adapter once it's completely inserted onto the stainless. Then I cut slots in the aluminum and installed the screws through the insulation blanket, rolled the aluminum skin back down and clamped it with one of the unused band clamps they include with it. I did use a generous amount of furnace cement on the adapter to flue collar connection at the stove, the fit was not particularly good.

You could probably secure the liner at the top of the chimney with screws if you wanted, but they would need to be below the line where the cap sits when installed. Also, you want to avoid screwing through the built-in band clamp. I didn't use any screws on my chimney flashing install into the liner, only the clamp.

As for the Roxul, yes, you will need to order a bale of it from Lowes and you'll have a ton left over. I can use the balance of my 'bale' elsewhere in the house but AFAIK there's no smaller quantity that you can buy retail.

good luck