Finally Getting Block Off Plate...Have Some Questions??

[jscs.moore]

So after getting a lot of great advice from the good folks on this site during our first burning season last year, I'm going to have the dealer install a block off plate to improve the performance of our Hampton HI300. Some background, we have a 2,000sq ft. Center Hall Colonial with a 28 foot exterior chimney. We had a 6'' ovalized pre-insulated liner installed when the insert was installed. The HI300 was great until the temps got into the 20's (and below)...then I had a much harder time keeping the house warm without also running the heat pump. Housie is well insulated with new high quality vinyl windows installed 2 years ago. I was also burning only kiln dried wood first year as cord wood was not quite ready. I am convinced I'm losing heat to 28ft of exterior chimney brick when it gets really cold so I am pulling the trigger to have the block off plate installed.

The dealer said they would install the block off plate and place and the "8lb insulating blanket" over the block off plate to help keep the heat in (Of course, it was the dealer who told me at install that a block off plate wasn't necessary)? So my question is...I've have read over and over again on this site to stuff as much Roxul up in the dampner area as possible? Should I just let the dealer install the block off plate and the "8lb insulating blanket" and leave it up to them as the professionals? Or should I get some Roxul and insist on having them stuff as much of it up in the dampner area before the install the block off plate?? I want this done right the first time so your feedback is greatly appreciated!

 

[begreen]

The 8" blanket will probably be about 1" thick kaowool. It's unknown whether the installer is going to evenly lay it out over the plate to the edges. Or the installer might just stuff it around the liner. You'll have to ask. For more insulation it could be attached to the back wall of the fireplace firebox too.

 

[jscs.moore]

The 8" blanket will probably be about 1" thick kaowool. It's unknown whether the installer is going to evenly lay it out over the plate to the edges. Or the installer might just stuff it around the liner. You'll have to ask. For more insulation it could be attached to the back wall of the fireplace firebox too.

Thanks Begreen...so how would you do it? Stuff as much Roxul up above the damper level and around the liner? I think I've read some of the posts on this site before that a block off plate is worthless without stuffing a bunch of Roxul into the damper level and around the liner to keep all the heat in the house? Other posts I have read basically say the block off plate will really do the job of keeping the heat from going up the chimney and the insulation is going to help but it's not that critical? Again...I just want to do it right the first time...thanks!

 

[begreen]

Even an uninsulated block-off plate is going to have some positive effect. If they fill the area above the plate with kaowool then it should be fine. Putting some insulation between the cold exterior back wall and the insert will also help.

 

[jscs.moore]

Even an uninsulated block-off plate is going to have some positive effect. If they fill the area above the plate with kaowool then it should be fine. Putting some insulation between the cold exterior back wall and the insert will also help.

Thanks! I believe the dealer plans to fill the area above the plate with the insulating blanket. I thought this sounded okay, but wanted to get some feedback from some of the pros on this site. I look up the kaowool and, as you say, it looks like the 8lb blankets are about 1 inch thick. So in my mind, it they have extra I'll just tell them to use it all above the plate. Thanks again for the feedback Begreen!!

 

[bholler]

If you want it filled get a bundle of roxul. The insulation blanket will work well but it is expensive. When we do block off plates we just spray glue a sheet of foil faced 1/2" insulation to the top of the plate and it helps allot but I am sure stuffing the smoke chamber full would be better. But you would have a couple hundred in ceramic wool to do that.

 

[Hogwildz]

Do the block off plate, seal it well. Insulate above with Roxul. You can get a bag of it at your local Lowes