Another issue< Ughhhh

[Woody Stover]

What is the proper heighth for the SS liner at the top?

On my flex liner, the instructions said to have no more than 3" of liner extending above the top of the masonry chimney. Creosote will form in that section because it is exposed and stays much cooler than the rest of the liner.

I've been peeking at this thread with BB's expertise. Everything looks good for a great repair, my concern is now with what woody said, with the extension on the chimney top. How much is enough and what length is too much? I believe mine comes out of the SS cover about 6 inches and then the cap sits down over that and screws in.

Mine also has about 6" above the top plate; Haven't got around to trimming it shorter yet. There wasn't all that much flaky creosote in that section, but more than there was down further. I brushed all of it down, but you could probably catch the heavy stuff and pull it out of the top. The installation instructions for your particular liner should tell you what length to trim it. Instructions for my Homesaver Roundflex says 3", Saf-T-Liner rigid pipe says 6". Not sure if you have one of those or class A...

 

[My Oslo heats my home]

I believe that when I put mine together I left some "just in case" space(6") for a whatever day...

 

[rakuz66]

Here you go BB, It looks like it is cemented in place, so I 'll need to make up any differnce below. What do you think about a block off plate? Thanks again.

 

[rakuz66]

Another pic BB

 

[BrotherBart]

Uh oh. Is that liner mortored into the flue tiles?

 

[My Oslo heats my home]

Rakuz, just out of curiosity, what does your second flue get used for? Also, if the SS cage is fixed (cemented in) how do you gain access to the flue for maintenance and repairs?

 

[rakuz66]

Uh oh. Is that liner mortored into the flue tiles?

I did not install the liner, but yes it looks to be cemented in at the top.

 

[rakuz66]

Rakuz, just out of curiosity, what does your second flue get used for? Also, if the SS cage is fixed (cemented in) how do you gain access to the flue for maintenance and repairs?

Sesond flue is for the gas water heater and furnace. The top of the SS cage comes off w/ screws.

 

[BrotherBart]

Forget pulling the liner up for the elbow install then. But in one recent post you said the stove was going to be pulled out of the fireplace so you can install the elbow while it is out.

 

[rakuz66]

Yep, stove is already out and being welded today. Just a few more questions, Should I install a block off plate? If so, I don't like what I'm reading abouit using Roxul for insulation above ( I read that it will blow around the house, if you use a blower, which I do) therfore is it ok just to install a block off plate w/out insulation? How do you attach the block off plate to the chimney? Last question, can I use hvac foil tape around the SS liner( will the tape burn) ? I'm ocd so I tend to go overboard with clamping stuff, thanks.

 

[begreen]

Although that 'might' happen with insulation just stuffed around the pipe, I don't think that is an issue when there is a metal block off plate. The insulation is above the block off plate which if properly installed will complete seal off the insulation from the house. Silicone the perimeter flange of the plate and use furnace cement around the liner. It will keep the insulation captive in the chimney.

 

[rakuz66]

Gothcha BG, stove is welded, looks like a great job! I guess my question is this? If my liner is mortarted in at the peak, ( please see pic) would I gain that much from adding a block off plate?

 

[begreen]

If it is an exterior chimney, yes. You'd be surprised how much heat cold masonry can suck out of a stove.

 

[rakuz66]

Nope BB, It's an interior chimney, so would it be worth the effort to put in a block off plate?

 

[BrotherBart]

Given that the piece of sheet metal is eight or nine bucks in the duct work section of Lowe's and making and installing the block off plate is at worst a thirty minute job, yes it is worth it.

https://www.hearth.com/econtent/index.php/wiki/Why_damper_seal_is_needed/

Edit: Curious. Every time I look at the pic of the top of that liner I get the feeling I am looking at an 8" liner?

 

[My Oslo heats my home]

Given that the piece of sheet metal is eight or nine bucks in the duct work section of Lowe's and making and installing the block off plate is at worst a thirty minute job, yes it is worth it.

https://www.hearth.com/econtent/index.php/wiki/Why_damper_seal_is_needed/

Edit: Curious. Every time I look at the pic of the top of that liner I get the feeling I am looking at an 8" liner?

I have to say it is an odd way to finish a flue liner install. BB what size clay liner is that if you think the SS liner is 8"? 9x9?

 

[begreen]

I'm guessing it is an 8"x8" or 8.5" x 8.5" OD clay tile. Same thing we had in our house for the defunct oil furnace.

 

[BrotherBart]

Just had to ask. May be the angle. May be the old eyes. Sucker just looks bigger than six inch.

 

[begreen]

Compare the flue width to the width of the chimney bricks which would be about 7.625" if standard brick.

 

[rakuz66]

No, it's 6 inch.

 

[rakuz66]

Ok guys, I'm ready to start a template for a block off plate, but I do have a question. My SS liner is sealed in at the top of the flue w/ cement. (as you can see in previous pics) Will this create any kind of problems with the added addition of a block off plate down below? Any draft or dead air space issues? Just curious.

 

[BrotherBart]

Yep both are issues. Good ones. The dead airspace holds heat and helps increase draft in the liner.

Get that thing in there.

 

[rakuz66]

Do you mean get the block off plate in there?

 

[Woody Stover]

My SS liner is sealed in at the top of the flue w/ cement. Will this create any kind of problems...

Yeah, shouldn't the liner be free to move up and down to allow for expansion when it gets hot?