What would require an wood burning insert to have a block off plate Vs. not requiring it to have one

[elkimmeg]

usually when buying a liner kit it includes the top flue cap and liner cap is clamped to the flue blockoff cap supporting the weight of the liner the vent cap is then installed and usually screw clamped in place many are simmilar to large auto radator hoses.

the block offf plate can be a PITA that is why a lot of installers want not to do them. BB suggest to use 5/8 to 3/4" gasket around the liner and plate glued in instead of furnace cement

I supose liner insulation can be stuffed in there or kro wool. This plate can turn into trial and error fitting. One can use more than one metal piece to make it up. One could cut the liner hole 1" larger to allow movement to its final resting place then cut another plate tight yo the pipe with enough overlap to caulk it in and apply a couple of sheet metal screws to hold it in place.

 

[jjbaer]

usually when buying a liner kit it includes the top flue cap and liner cap is clamped to the flue blockoff cap supporting the weight of the liner the vent cap is then installed and usually screw clamped in place many are simmilar to large auto radator hoses.

the block offf plate can be a PITA that is why a lot of installers want not to do them. BB suggest to use 5/8 to 3/4" gasket around the liner and plate glued in instead of furnace cement

I supose liner insulation can be stuffed in there or kro wool. This plate can turn into trial and error fitting. One can use more than one metal piece to make it up. One could cut the liner hole 1" larger to allow movement to its final resting place then cut another plate tight yo the pipe with enough overlap to caulk it in and apply a couple of sheet metal screws to hold it in place.

Elk,

Any thoughts on my second question....once the liner is installed and has been fed through and attached to the block=off plate, you then need to connect it to the insert. Is ther generally enough room in the hearth to slide the insert back into position in the hearth and then reach over the top of the insert from the front to make the final connection or do you have to make the connection, then compress the liner as you slide the insert back into position?

 

[Highbeam]

My liner installed through a masonry chimney was connected to the insert after sliding the insert in place. The top was unclamped so the liner could be properly lengthened before attachment to the insert. You could always unclamp the top in the future to allow the liner to slide around as needed for insert adjustments. I see no need to pull that insert out of the firebox after the liner is installed, that was one of the reasons for the liner.

 

[elkimmeg]

castiron I use some boards and wood dowels so I can slide the insert in and out making trial connections when I get to wher it needs to be I roll it in the final time remove the boards and dowels and make my final connection to the flue collar after the second overlap piece if fit around the liner and caulk and fasten it in place. It all depends upon the amount of working room one has above the insert as to what sequence of method is best. Another idea when space is real tight is to place sheets or strips of sheet metal on the hearth the smooth surface makes it easier to pull out the insert for connection adjustments. T What I have done is allow the liner to move up i and down in the flue make the final connection to the stove then rtim the liner and install the top plate and vent cap. If you cut it first and it is an inch too short your screwed or you will need a connector piece. you might need a 24 gage stove pipe adjustiable elbow attached to the insert of make up angle difference to where the liner connects. There can be a lot of trial and error and test fitting involved to get it right

 

[jjbaer]

My liner installed through a masonry chimney was connected to the insert after sliding the insert in place. The top was unclamp so the liner could be properly lengthened before attachment to the insert. You could always unclamp the top in the future to allow the liner to slide around as needed for insert adjustments. I see no need to pull that insert out of the firebox after the liner is installed, that was one of the reasons for the liner.

My thought was that any movement of the insert after the liner has already been cemented to the block-off plate either 1) moves the block-off plate out of position or 2) loosens the seal where the liner is cemented to the block-off plate.

The only alternatives I see are: 1) do as you suggested and slide the insert into position and then make the final connection from in-front of the insert and by reaching over the insert or 2) if you don't have the room and if you have to pull the insert out a bit to make the connection, there must then be some "accordion type flex" in the liner in the short length between the insert and the block-off plate so that when you slide the insert into its final position, the liner compresses without breaking the block-off plate seal or dislodging the plate entirely.

Sounds like you're able to do the first but if one can't, does this type liner easily compress in a small distance like I have described?

 

[BrotherBart]

cast I have installed a double wall and a single wall liner flex liner and I'll be darned if can see how any elongation or compression is possible with them. They may look accordian like but they are stiff. In fact with the double wall the word "flex" barely applies.

 

[jjbaer]

cast I have installed a double wall and a single wall liner flex liner and I'll be darned if can see how any elongation or compression is possible with them. They may look accordian like but they are stiff. In fact with the double wall the word "flex" barely applies.

BB,

so..if you want to seal the liner to the blockoff plate, you've really gotta first cut the liner to length, then seal the liner to the block-off plate and then slide the insert into the hearth and then make the final connection (insert to liner) with the insert in its final resting place. Otherwise if you make the connection out in the room and then slide the insert into place, the liner must then be pushed up the flue and you then can't access the blockoff plate to seal it to the liner. Correct?

 

[jjbaer]

Elk,

What would one need for a wood burning insert: a single or double wall SS liner in the flue? Also, how do you tell if you need to wrap the liner with insulation or not?

 

[BrotherBart]

cast I have installed a double wall and a single wall liner flex liner and I'll be darned if can see how any elongation or compression is possible with them. They may look accordian like but they are stiff. In fact with the double wall the word "flex" barely applies.

BB,

so..if you want to seal the liner to the blockoff plate, you've really gotta first cut the liner to length, then seal the liner to the block-off plate and then slide the insert into the hearth and then make the final connection (insert to liner) with the insert in its final resting place. Otherwise if you make the connection out in the room and then slide the insert into place, the liner must then be pushed up the flue and you then can't access the blockoff plate to seal it to the liner. Correct?

Yep.

 

[jjbaer]

cast I have installed a double wall and a single wall liner flex liner and I'll be darned if can see how any elongation or compression is possible with them. They may look accordian like but they are stiff. In fact with the double wall the word "flex" barely applies.

BB,

so..if you want to seal the liner to the blockoff plate, you've really gotta first cut the liner to length, then seal the liner to the block-off plate and then slide the insert into the hearth and then make the final connection (insert to liner) with the insert in its final resting place. Otherwise if you make the connection out in the room and then slide the insert into place, the liner must then be pushed up the flue and you then can't access the blockoff plate to seal it to the liner. Correct?

Yep.

BB,

What are your thoughts on insulating the liner?

Jim

 

[JayY]

I wonder why the stove manuals are so ambiguous about this issue. Below is a quote from my Elite 33 insert manual. It doesn't say anything about a blockoff plate with a reline. I had my stove professionally installed. I will have to check for this.

"Block-Off Plate Installation
Whenever this appliance is installed with a direct connection a block-off plate, or other non-combustible
seal-off device (e.g. damper adapter), will need to be installed. This device is used to seal the chimney,
insuring no smoke enters the home and providing the chimney system with a seal to promote draft. The
directions below detail the steps for construction and installation of a block-off plate."

 

[BrotherBart]

BB,

What are your thoughts on insulating the liner?

Jim

I think insulating the liners is great if you have room for it. I could barely get the liners down my flues so insulation was out of the question. I did pack the top four feet of each with rock wool and on the one in the fireplace there is a foot of rock wool on top of the block off plate. On the one in the basement office their is two feet of fiberglass stuffed into the bottom, well below the thimble.

Since we are in a location where it does not get in the teens too much draft hasn't been a problem.