Block off plate, roxul, code?

[qwertyjjj]

Can roxul be placed directly above a wood burning stove and right next to an insert?
I have a big problem with cold air coming in in the winter and want to install a block off plate.
On a related question, we have a second fireplace with flue. It seems to have pink insulation (fiberglass?) touching the flue & is that allowed under code?

 

[Squisher]

I say yes. I think it's been debated on here before? I believe as long as the manufacturers instructions don't prohibit it or it's proximity for some reason(like I don't think you can blanket a stove with it) it is perfectly fine and acceptable to use in block off situations for insulation. It wouldn't negate any other requirements for clearance to combustibles or act as a certified insulation, but IMO it is a fine thing to stuff up in a damper/smoke shelf/above the block off plate when lining.

Roxul states non-combustible with a melting point of 2150f on this product:

http://www.roxul.com/products/roxul-safe/

 

[Squisher]

Pink insulation is considered a combustible and would not be allowed.

 

[qwertyjjj]

Do you think a block off plate is the best solution for an outside brick chimney with an insert and a big stack effect/cold draft problem?
I assume a damper is a no go at the bottom for to the insert.
A damper at the top will get frozen by the ice in winter.

 

[bholler]

Do you think a block off plate is the best solution for an outside brick chimney with an insert and a big stack effect/cold draft problem?
I assume a damper is a no go at the bottom for to the insert.
A damper at the top will get frozen by the ice in winter.

You dont use any damper with an insert. And yes a block off plate is the best way to install. But that atack effect needs fixed if you ever want your insert to work right

 

[qwertyjjj]

You dont use any damper with an insert. And yes a block off plate is the best way to install. But that atack effect needs fixed if you ever want your insert to work right

Won't the block off plate fix the stack effect? It's air coming down the old chimney not necessarily the flue insert.
Or do you mean something else needs sealing. We had an air pressure test done. They recommended more insulation in the roof but not sure that's the cause of the problem.
Seems to work fine once the fire is starting, drafts well.

 

[qwertyjjj]

Pink insulation is considered a combustible and would not be allowed.

Does it need a clearance or is it just not allowed at all near a flue?

 

[bholler]

Won't the block off plate fix the stack effect? It's air coming down the old chimney not necessarily the flue insert.
Or do you mean something else needs sealing. We had an air pressure test done. They recommended more insulation in the roof but not sure that's the cause of the problem.
Seems to work fine once the fire is starting, drafts well.

If air is coming down the chimney it is probably due to negative pressure in the house. Which you attributed to a stack effect. Which would require air sealing on the second floor to remedy

 

[bholler]

Does it need a clearance or is it just not allowed at all near a flue?

It would need 18 inches

 

[qwertyjjj]

If air is coming down the chimney it is probably due to negative pressure in the house. Which you attributed to a stack effect. Which would require air sealing on the second floor to remedy

The air pressure test we had done says there is an issue with air escaping but it would be almost impossible to seal fully. Even if we implement all their recommendations, the house would only move from a rating of 62 to 69.
I thought with a stack, hot air escaped up the chimney and cold comes down when not in use?

 

[bholler]

The air pressure test we had done says there is an issue with air escaping but it would be almost impossible to seal fully. Even if we implement all their recommendations, the house would only move from a rating of 62 to 69.
I thought with a stack, hot air escaped up the chimney and cold comes down when not in use?

No in a house stack effect means air excaping the top floor pulling a negative pressure on the first floor. The top of the chimney should be sealed around the liner to the top anyway stopping a stack effect there.

 

[qwertyjjj]

No in a house stack effect means air excaping the top floor pulling a negative pressure on the first floor. The top of the chimney should be sealed around the liner to the top anyway stopping a stack effect there.

Should it have a liner and a block off? I'm pretty sure there's no liner otherwise no air would be coming down?

 

[bholler]

Should it have a liner and a block off? I'm pretty sure there's no liner otherwise no air would be coming down?

Yes you need a liner and there would be no way to do a blockoff plate without one. I would say you need a chimney professional to look at it.

 

[qwertyjjj]

Yes you need a liner and there would be no way to do a blockoff plate without one. I would say you need a chimney professional to look at it.

The only chimney professional in the area is probably the one who installed the other fireplace with pink insulation. I think I'd rather get up there myself and take a pic
So, if there is a liner, how am I getting a cold draft from underneath the stove?

 

[bholler]

The only chimney professional in the area is probably the one who installed the other fireplace with pink insulation. I think I'd rather get up there myself and take a pic
So, if there is a liner, how am I getting a cold draft from underneath the stove?

There are many possible explanations but without knowing what you have there is no way for me to even make a guess.

 

[moresnow]

Pics for the pro's please! Snap a few to help elaborate on your setup.

 

[kennyp2339]

Was waiting to see this type of post .... Ladies and Gents start you 2017-2018 winter season

 

[begreen]

The only chimney professional in the area is probably the one who installed the other fireplace with pink insulation. I think I'd rather get up there myself and take a pic
So, if there is a liner, how am I getting a cold draft from underneath the stove?

Does the stove or the fireplace have an outside air supply? Is there a proper top cap on the chimney?

 

[qwertyjjj]

Pics for the pro's please! Snap a few to help elaborate on your setup.

Used to have outside air for the old chimney but I blocked it. The cold air used to be felt in the brick vents but I blocked those too as you can see in the pic. The cold air is now felt from underneath the fireplace.

I had a look at the top. It looks to be carried and looks to be sealed with a metal plate. However looks like the metal plate might have lifted a bit on one side.

 

[begreen]

Its that top cap sealed to the chimney cap on all sides or sort of floating above it? the right side picture seems to have a gap underneath it, but this might just be the picture. If there is a gap, it needs to be sealed with silicone.

 

[bholler]

Used to have outside air for the old chimney but I blocked it. The cold air used to be felt in the brick vents but I blocked those too as you can see in the pic. The cold air is now felt from underneath the fireplace.

I had a look at the top. It looks to be carried and looks to be sealed with a metal plate. However looks like the metal plate might have lifted a bit on one side.

View attachment 199153 View attachment 199154 View attachment 199155 View attachment 199156 View attachment 199157

It does look like you have a liner though. But it should be confirmed that it is attached to the stove correctly

 

[qwertyjjj]

It does look like you have a liner though. But it should be confirmed that it is attached to the stove correctly

Looks like it is. Wouldn't I get smoke inside if it wasn't?

Its that top cap sealed to the chimney cap on all sides or sort of floating above it? the right side picture seems to have a gap underneath it, but this might just be the picture. If there is a gap, it needs to be sealed with silicone.

This a better pic? Not sure what you mean exactly
Edit: if you mean just the cap by itself, then it must be attached as it would have flown off or be pushed off by snow over the years I imagine.
If I steak with silicone then is it still best to put a block off plate in below?

 

[begreen]

Looks like it is. Wouldn't I get smoke inside if it wasn't?

This a better pic? Not sure what you mean exactly
Edit: if you mean just the cap by itself, then it must be attached as it would have flown off or be pushed off by snow over the years I imagine.
If I steak with silicone then is it still best to put a block off plate in below?

View attachment 199163

The top cap is the plate that attaches to the chimney crown and also provides an anchor for the liner. Hard to tell from the picture, it looks like it has an anchor at each corner so it may be ok. If the liner is attached to it then that will stop it from getting pushed off.

 

[qwertyjjj]

So, the draft coming down is pretty strong in winter.
If the top was sealed, you're saying there would be no draft?
Is it worth putting the block plate in?
Won't cold air come down the insert as well?

 

[qwertyjjj]

Is there a type of concrete/ceramic board I can use for the block off plate instead of sheet metal?