DIY Insert install

[Xtrl9]

Hello and welcome to what I believe is part 4 of the heating conundrum at my house. Some of you may recall from my other threads I had some water entering the house and no small amount of confusion about putting an insert in vs running a liner to the basement with the smoke dragon in it. The recap of current information is as follows. I have a 3 story 3 flue cinderblock chimney with rubble veneer that sits on my foundation and penetrates my roof(s). The flue I'm going to hook up a Heartstone Clydesdale with 6" insulated flex liner(flex king pro) to is a 23' run in a 10"x14" terracotta flue that travels out from the middle floor firebox at a 45 degree angle for ~3' then runs straight up. Top dimensions of the chimney crown are 56"x40" no drip edge. I'm planning on using roxul and durock to insulate my firebox at a minimum on the smoke shelf/block off plate and on the side closer to the exterior wall, due to the reasoning that my chimney is a ton of rock to heat that I'd rather keep in the rooms. The side closer to the upstairs and hall way bedrooms I might just use durcock. I have some high temp 2200 dF paint I'm going to shoot the roxul with to seal in the fibers, also with the help of mellow's thread and the wiki article I think I can handle the block off plate fabrication no problem.






Current questions:
10"x14" shouldn't have any problem with 6" insulated liner even with the bend in there?

High temp silicone was suggested as part of the insert kit and was suggested to be used where the adapter goes into the back of the insert help seal up the air gaps from the crimped edge. "High temp silicone" is only rated at 500 dF; wouldn't that be exceeded after the break in burns are done? If so, its it just a shove it in and forget it or is some form of securing recommended?

Got an IR gun on the way to monitor stove temps, how in the heck would I get flue temps with this set up? 18" from the stove would be me drilling a hole through 3" of stone and then penetrating the liner with a "stabby" probe?

The water entering the house seems to have changed its behavior. Last spring/winter it was running out of the stone where the picture is on the mantle, this fall with all the rain we had the last month it was running down inside the of the flue, dripping off the metal part of the smoke shelf. I'm going to get a piece of 304SS sheetmetal to extend 2" beyond the crown on all 4 sides to help shed water, with my kit I got the 13"x18" cap to further discourage water running down the flue/chimney where the terracotta is "cemented in" any other ideas on this?

 

[Woody Stover]

I'm not sure but the FlexKing Pro may be a two-ply liner, something the experts here advise against. I know the heavy-wall single-ply liners are able to flex around angles pretty well, but I don't know if it can make a 45* angle with insulation in your configuration. It looks like where the liner connects to the Clydesdale is on an angle, so maybe you wouldn't need an elbow at the bottom of the liner. Who suggested the silicone at the flue collar? I wouldn't think there would be any chance of leakage there, especially with 23' of stack, except for a little air being drawn into that slight gap. There is some 1000, 1100* caulk out there, however. You still have to secure the liner to the flue collar with screws, though. See the liner company's installation instructions and stove manual for clarification. It's usually hard to install a flue probe on an insert. As long as you keep the fire under control, especially at startup when trying to get the stove up to temp, you shouldn't be heating the bottom of the liner excessively. No roaring fires! The stainless extension off the edge of the crown sounds like it would work. You might want to put a bead of polyurethane caulk around the perimeter on the underside to form a drip edge so the water can't flow on the underside of the stainless, back toward the crown. Or maybe come up with another idea for a drip edge.

 

[bholler]

Yeah Iwould stay clear of flex king pro or similar products in their line I would recomend flex king hd with regular flex king a second. The 2 ply stuff is just not durable.

 

[Xtrl9]

flex king pro is double wall AKA 2ply, I had read that you just didn't want the light duty single wall stuff? The insert adapter is just a piece to connect the liner to the insert, I hope its attached with band clamps but I will use screws or whatever the manufacturer specifies.

Chimney Liner Depot (the people who made flex king pro) said that might want to put the "high temp" silicone between the liner and appliance, this sounded like a bad idea to me. I already have a tube of it so I might use that up top to secure the stormcap/plate.

I was actually considering using rubberized undercoating on the surface of the crown between the piece of SS but I don't know how hot the masonry will actually get. Also looking at having another 1" where the edges are bent down after they extend 2" off

 

[bholler]

flex king pro is double wall AKA 2ply, I had read that you just didn't want the light duty single wall stuff?

The pro is the same thickness but the inner layer is not attached on the bottom edge at all. Because of this it is prone to kinking and buckling when bent and can easily be snagged by a brush. The regular light wall will hold up better and the heavy wall will hold up much better.

Chimney Liner Depot (the people who made flex king pro) said that might want to put the "high temp" silicone between the liner and appliance, this sounded like a bad idea to me. I already have a tube of it so I might use that up top to secure the stormcap/plate.

Yes very bad idea for a wood stove

 

[Xtrl9]

Well I'm madder than hell because the guy on the phone told me Pro was better for woodstoves and that it was "tough and tearing it isn't a concern".

 

[bholler]

Well I'm madder than hell because the guy on the phone told me Pro was better for woodstoves and that it was "tough and tearing it isn't a concern".

Did you order it already?

 

[Xtrl9]

Yep, its arriving tomorrow. Plus side is it looks like I can buy an Olmpia foreverflex online now that wasn't an option when I was planning this all out a year ago.

The reason I'm mad is I was going to buy the HD, that's literally a downsell for them and an inferior product for me.

 

[bholler]

The reason I'm mad is I was going to buy the HD, that's literally a downsell for them and an inferior product for me.

Yeah it is hd is much better