Roxul-Block Off Plate

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Hearth Supporter
Feb 14, 2007
Maple Glen, Pa.
I built a block off plate for my Lopi Insert, pics attached,,,it's not pretty, but it works. Anyway, my stove is on an inside wall with the liner going up thru the flue and surrounding chimney. My plan is to stuff roxul down the flue around the liner, and also having it lay on top of the block off plate. Is this safe to do? The Block Off plate sits 9 inches above the stove. Disclaimer: I built the block off plate years after the install. This would be much easier to do than taking the liner out and insuating it with the wrap stuff and putting it back in, plus, I don;t think I have the clearance in my flu ( see pic). In hindsight I should have insulated the liner while building the block off plate, but I didn't, and I have lots of roxul. Or,should I start over and rebuild, as this liner is around 15-16 years old.? Anyway, thanks for any advice,,,

Roxul-Block Off Plate Roxul-Block Off Plate Roxul-Block Off Plate
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It doesn't look like there is room to insulate the liner without ovalizing it first. Given its age it might be better to start out with a new oval liner.
I vote for starting over too. If you broke out the terra-cotta, you’d have room for the insulation.
Ok, thanks for your input! Would you also recommend rebuilding the block off plate? And is it ok to put ROXUL on top of the plate ? Rebuilt or not? I just want to get this right this time, thanks again. Also, can you purchase a block off plate? Or ,, I was thinking of having one fabricated for me.
I would rebuild the plate the idea is to get something air tight with small enough gaps that can be sealed. My understanding is that rolux is ok on top and encouraged. One thing that helped me make mine was using cardboard as a template.
Yes, try to get everything as tight and well built as possible. It’s not a bad thing at all to pack Roxul around the top and bottom of the chimney.
So, as a follow up with 3 different companies, I got 3 different answers. One said leave it as is since you never had any problems and insulating an interior liner isn’t necessary. The second wanted to take out terra cotta, re-use old liner and insulate. The third wanted to knock out the terra cotta, replace old liner with new liner and insulation, install plate on bottom of chimney, and raise chimney to 3ft off ridge. ( it’s about2ft now). I had a pretty good feeling about #3.
Here’s my dilemma, I can’t afford to have the chimney rebuilt right now. Does it make sense to contract with #3 and start with removing terra cotta, use old liner with insulation and add the extra 16-20 inches of pipe at a later date, when I can afford the chimney work? Can you couple a SS pipe? Common sense tells me, no coupling would be better, but if this gets me through a year or two, I think I might choose this option, unless he tells me old SS pipe is no good. Then, it’s a major problem.
Then I read about oval duraliner as a possible solution, I really like the sounds of leaving everything as is, and buying insulated duraliner oval pipe and running that through the terra cotta, but I can’t find an installer around me (outside Philadelphia Pa). It just seems a shame to remove terra cotta, doesn’t that provide some type of safety? Anyway, any advise is again appreciated, thank you!
I'm not in favor of temporary solutions. They tend to become permanent as other projects come up and take precedence later on.

Duraliner is one option. Another is to to install an ovalized liner that gets insulated on site. Any professional, certified sweep should know how and have the tools to do this. A well equipped shop will have an ovalizing tool. If not, the oval liner can be purchased in advance.
Any liner must be sized-matched to the stove's flue requirement, round or oval.