Block off plate vs insulation

[SterlingSL]

Trying again...

The installer is coming tomorrow 1/12/17. He's putting in a Regency I3100 insert into my existing ~30 year old heatform by Heatilator (at least that's what I was told it was). They are removing several heat tubes to install the liner and maybe some of the existing damper.

We agreed on a two-phase install:
1. liner
2. Insert

In between the two steps will allow me to go in there and fabricate a block-off-plate. However the mentioned they can stuff the existing damper with insulation, they will not do the block-off-plate for me though - that's up to me.

My question and I need to know before they get here: will the insulation stuffed into the damper be sufficient?

 

[Squisher]

No. definetly do the block off plate. Not only will it be more effective it will stop insulation bits or particles from dropping down onto your insert and being blown all throughout your living area. You may wonder how that would happen? Well obviously initially but also from heating and cooling when using it, and from cleaning it.

To clarify I would recommend stuffing with roxul and doing a block off plate sealed up as best you can.

 

[SterlingSL]

No. definetly do the block off plate. Not only will it be more effective it will stop insulation bits or particles from dropping down onto your insert and being blown all throughout your living area. You may wonder how that would happen? Well obviously initially but also from heating and cooling when using it, and from cleaning it.

To clarify I would recommend stuffing with roxul and doing a block off plate sealed up as best you can.

Thanks - what do you mean by 'stuffing with roxul'? They told me they would 'stuff it with insulation' and I have no idea what they meant by that either. I was planning to sort of follow the block off plate instructions that I found here somewhere. I believe it had the Roxul placed above the sheet metal or Durock plate that is the first portion of the BOP above the stove.

 

[Squisher]

Yah roxul is just a brand of insulation that I would use for doing that, you just wouldn't want to use pink insulation IMO which I believe could melt/combust possibly. Above the block off plate and up into the smoke chamber area is where I stuffed roxul on my insert. I used a long stick to push and jam it up into the smoke chamber.

Is the liner itself going to be insulated? If not make sure the original chimney lining isn't compromised and that all clearances to combustibles are honoured (2" interior 1" exterior the length of the chimney). Even if that's the case a insulated liner is strongly recommended for performance, espescially if it's an exterior chimney.

 

[Elciteeve]

ROXUL insulation provides the comfort you want and the security you need. A fire-resistant insulation, ROXUL resists temperatures of up to 2150◦F (1177◦C) without burning or melting (thanks roxul.com)

Glass can only be molded at very high temperatures. It completely melts/liquifies at approximately 1400 °C to 1600 °C (thanks google)

"Pink stuff" is simply spun glass. The paper on it however, does indeed burn. The Roxul isn't fireproof where as glass is. They are simply different. Not sure which one is best for this application though. I suspect your stove isn't going to get anywhere near either of those temps.

 

[Squisher]

Interesting info. It seems from those numbers either would be fine but I've always been under the impression roxul is preferred over pink? Hopefully some experienced installers may pipe in?

I don't believe either is listed, so technically approved to be used. That would leave the ceramic/kaowool type of insulation blankets used on the liners and in stoves themselves for a listed product?

 

[maple1]

I would not use pink. Or any other colour fiberglass.

Ever throw a piece of it into a fire?

Roxul all the way.

 

[kennyp2339]

Pink will melt and off gas, roxal wont do anything until 2150deg..steel melts at 2,750deg f so if you get the stove up to roxals temp at 2150 deg f you already have bigger problems going on.

 

[SterlingSL]

I'm pretty sure when they told me they would stuff the damper with insulation, they probably meant some kind of fireproof insulation. I'm going to be there while they install and if they tried putting the Pink in there, I would immediately cease operations, and call the place I'm buying the stove from and ask what they hell they think they're doing. I would assume using regular old wall insulation would violate nearly every ordinance the city has.

I'm just wondering if shoving insulation up there without the plate would suffice, let's just assume they're using Roxul.

 

[kennyp2339]

I'm just wondering if shoving insulation up there without the plate would suffice, let's just assume they're using Roxul.

Over time the Roxal gets very dusty / powdery and will sag, you need to have it sealed off from any moving air or you'll be fighting a dust bunny army, not to mention its prob bad to breath in all the time

 

[Squisher]

I was warned, as I'll pass on again. That you won't want roxul fibers falling down and getting blown around your living area. I used roxul in my insert install I did about six weeks ago and it's been fine, no odour or any issue. I fabbed up a down and dirty block off plate out of cold air furnace return sheet metal and it's been a lot better than nothing. I think the more sealed it could be the better.

 

[Squisher]

Is the liner itself going to be insulated? If not make sure the original chimney lining isn't compromised and that all clearances to combustibles are honoured (2" interior 1" exterior the length of the chimney). Even if that's the case a insulated liner is strongly recommended for performance, espescially if it's an exterior chimney.

What about the liner and chimney? Insulating a liner greatly ups performance and safety if there is any question of the original clay liners integrity.

 

[jatoxico]

I'm pretty sure when they told me they would stuff the damper with insulation, they probably meant some kind of fireproof insulation. I'm going to be there while they install and if they tried putting the Pink in there, I would immediately cease operations, and call the place I'm buying the stove from and ask what they hell they think they're doing. I would assume using regular old wall insulation would violate nearly every ordinance the city has.

I'm just wondering if shoving insulation up there without the plate would suffice, let's just assume they're using Roxul.

Add the plate. It stops air flow, reflects heat and keeps fibers from getting in house. I had to specify the use of Roxul for my install. Off topic but they still did it wrong, but anyway...even though it is the better product I don't think it's been specifically tested for the application and they may not want to use it. I think @bholler knows about this. IMO if you want to save yourself some aggravation just pick up the Roxul and do it yourself. You will spend more time and do a better job insulating well than they are likely to do.

My stove was installed and used for a year before I asked the dealer to come back so I could insulate correctly and put a plate in. I did exactly what you're doing. Dealer came out and removed stove. I insulated put in the plate then they came back and put it in place. Did what Squisher did, used a stick to push Roxul up as high around the liner as possible then really fully stuffed the smoke shelf down to the lintel then added the metal plate.

 

[kennyp2339]

What about the liner and chimney

Yo ... I just realized were are from the same town, Vernon, although my Vernon is in NJ, yours in BC, but we're still Vernon bro's

 

[jetsam]

ROXUL insulation provides the comfort you want and the security you need. A fire-resistant insulation, ROXUL resists temperatures of up to 2150◦F (1177◦C) without burning or melting (thanks roxul.com)

Glass can only be molded at very high temperatures. It completely melts/liquifies at approximately 1400 °C to 1600 °C (thanks google)

"Pink stuff" is simply spun glass. The paper on it however, does indeed burn. The Roxul isn't fireproof where as glass is. They are simply different. Not sure which one is best for this application though. I suspect your stove isn't going to get anywhere near either of those temps.

Fiberglass insulation starts melting at 500F or below, which is about 2000 degrees less than 1400C, despite any claims to the contrary you might find on manufacturers' spec sheets. Anyone who doesn't believe me can go up on their roof and pull out a chunk of the stuff their installer used around the top of their flue.

http://www.engineeringtoolbox.com/insulation-temperatures-d_922.html

I can't imagine why it is a commonly used material for that purpose. When I ripped mine out it was all melted where it had contacted the flue pipe.

 

[jscs.moore]

Trying again...

The installer is coming tomorrow 1/12/17. He's putting in a Regency I3100 insert into my existing ~30 year old heatform by Heatilator (at least that's what I was told it was). They are removing several heat tubes to install the liner and maybe some of the existing damper.

We agreed on a two-phase install:
1. liner
2. Insert

In between the two steps will allow me to go in there and fabricate a block-off-plate. However the mentioned they can stuff the existing damper with insulation, they will not do the block-off-plate for me though - that's up to me.

My question and I need to know before they get here: will the insulation stuffed into the damper be sufficient?

Wish I had room to fit the I3100...my fireplace couldn't go that big so I have the Hampton HI300. Love my insert but it would be great to have the larger firebox of the I3100 Definitely do the block off plate, I went a year without one because the dealer dismissed it. Had the come back on my dime this past fall to have them install one and the difference in heat & efficiency of the burn is substantial. You will also be much happier knowing the job was done right from the get go rather than having to second guess yourself and wonder if you could be getting much better heat & efficiency if you the block off plate. Good luck with that beast...I'm sure you'll love it

 

[jetsam]

if they tried putting the Pink in there, I would immediately cease operations, and call the place I'm buying the stove from and ask what they hell they think they're doing. I would assume using regular old wall insulation would violate nearly every ordinance the city has.

Actually, I think pink fiberglass is the normal thing, and they'll probably be stunned if you ask for anything else.

As previously noted, it is not a very good material for this application, so I am not sure why exactly it is so commonly used.

You may avoid delays and arguments by just going to Home Depot and grabbing a bag of Roxul, which costs about $50, and having it on site. They won't object to substituting that for the fiberglass if they don't have to delay the job or pay for the materials.

 

[SterlingSL]

Actually, I think pink fiberglass is the normal thing, and they'll probably be stunned if you ask for anything else.

As previously noted, it is not a very good material for this application, so I am not sure why exactly it is so commonly used.

You may avoid delays and arguments by just going to Home Depot and grabbing a bag of Roxul, which costs about $50, and having it on site. They won't object to substituting that for the fiberglass if they don't have to delay the job or pay for the materials.

Our local Home Depot has this, do you think it's ok? Looks specifically designed for putting between ceiling joists. I guess it will break apart enough to put around the flue?
Roxul Safe 'n' Sound 3 in. x 15-1/4 in. x 47 in. Soundproofing Stone Wool Insulation (12-Roll)

Lowes has the following:
Roxul Wood Stud R23 39.8-sq ft Unfaced Rock Wool Batt Insulation with Sound Barrier (15.25-in W x 47-in L)

Roxul Wood Stud R30 30.7-sq ft Unfaced Rock Wool Batt Insulation with Sound Barrier (23-in W x 47-in L)


Next question: if they show up with a non-insulated liner - send them home? My chimney is sort of internal: the backside is in my garage. Do I really need insulated liner?

 

[yooper08]

Why not use any left over ceramic insulation from your liner (assuming it's getting insulated)? Perhaps this is what they're thinking.

 

[yooper08]

To your question about Roxul breaking apart, it's easy to cut with a decent serrated knife (think bread knife, they'll typically have some of these hanging by the bags).

Safe'n'Sound doesn't have much in terms of thermal insulation, it's designed to be a fire retardant and sound barrier. I've never been able to find what it's R value is.

 

[Squisher]

As I mentioned before if clearances can't be confirmed or if the integrity of the existing clay liner is at all in question than you need insulation.

Even if those things are fine and you don't need insulation, really you still want it.

I wouldn't be sending anyone packing. It should be clearly laid out in the quote if it's insulated or not, and if it's not mentioned assume it won't be.

 

[jetsam]

For what you're doing, you can also use any kind of a serrated knife or large scissors that you don't mind blunting up, or just rip it- it tears fairly easily by hand, though your edges will be seriously raggedy. It cuts a lot like fiberglass. Big serrated knife is the recommended method.

The Roxul safe'n'sound in the brown bag is the one to get (though the others have the same melting point, so it will be fine if you get the R15 in the blue bag instead). The safe'n'sound is a little denser than the other stuff. I wouldn't get the R23 or R30 products as they are thicker, and it's a lot easier to put 2 layers of R15 than it is to rip R30 in half.

 

[jetsam]

To your question about Roxul breaking apart, it's easy to cut with a decent serrated knife (think bread knife, they'll typically have some of these hanging by the bags).

Safe'n'Sound doesn't have much in terms of thermal insulation, it's designed to be a fire retardant and sound barrier. I've never been able to find what it's R value is.

Like fiberglass insulation, the more you compress air space out of it, the lower the R value gets (this is why we don't stuff R30 into a 2x4 wall; it's worse than R13), and safe'n'sound is denser right from the factory. "What is the R value of this stuff" is a FAQ on their website, and their answer is "neener neener we're not telling".

From handling both products, I don't think the R value can be vastly lower because the density is not vastly different. I'd choose it over the regular insulation for a flue, but I don't think it really matters which one you pick.

 

[Hogwildz]

Yes block off plate, no fiberglass insulation, yes Roxul insulation.

 

[kennyp2339]

R value is.

roxal with a thickness of 6" is r15