Check this insulation job - first experience and want to ensure it is right

[ginkgotrees]

Hi all,

I recently had help from people around here selecting a stove insert and went with a PE summit. We are now checking the final details of the install before signing off on approval of the workmanship, and I want to check on insulation to make sure something is not amiss.

Here is how they insulated the PE Summit. Please take a look.


I have read around here that the essentials of a new install are an insulated liner, a block-off plate, and insulation for an exterior-facing fireplace (which this is). So I asked for all of these things and got them.

I was imagining the brick walls would have slabs of Roxul or something which is what I have seen around here. They wrapped the unit itself, including the sides, back, and top. They said they use ceramic insulation, and I have read about avoiding fiberglass. My main concern is if they blocked any intakes or if this could make the unit too hot. I imagine that slabs of Roxul would still insulate the space and make it hot, but is this normal practice to wrap insulation around the insert? Should it have any facing as pictured or not (foil-face in this case). Should it be modified before we approve the work? Our old insert had no insulation, so I do not know.

On a related note, we have an old ash door I was planning to just add insulation to to protect from heat loss out of the old chute.

Here's the block-off plate, as well. I asked for insulation above it, too, so this seems in order.


Your collective knowledge and experience is much appreciated. If I need to call PE directly to find out of this is acceptable, I will do so, I just thought I would check around here first.

 

[webby3650]

Insulating the insert it self is not common. It doesn’t really address the issue of radiant cold infiltration through the brick. It isn’t an approved method of installation, insulation shouldn’t be laying on the insert. It’s not really common for an installer to insulate the firebox either, but if you specifically asked for it to be and they agreed, then they need to make it right.

 

[ginkgotrees]

Well, I had asked for insulation within the brick fireplace. I was not expecting them to wrap the insert itself, just add the ceramic insulation around edges of the bricks. Perhaps this was just a miscommunication between what I was asking and what they heard. I have contacted PE to ask about this. My inclination is to have them just remove the insulation wrap entirely and not replace it with anything. I would almost rather do it myself correctly later than risk overheating the unit now.

I have seen a few references to a detailed post on the topic of wrapped inserts but cannot find it.

 

[Hogwildz]

As long as the insulation is outside the outer casing of the insert, you'll be fine. Not many insulate the old firebox, but some have and feel they have better results. None here and have no issues. Heats 2666sf just fine.

 

[ginkgotrees]

As long as the insulation is outside the outer casing of the insert, you'll be fine. Not many insulate the old firebox, but some have and feel they have better results. None here and have no issues. Heats 2666sf just fine.

I believe it was just the outer casing, they did not open the insert. Here's an image of the unit just before insulation. They just wrapped the outside of it, though I don't recall if it covered the holes in the back or if they cut openings.

 

[Hogwildz]

The lower rear hole is for the secondaries, that should not be covered. The upper ones are just grab holes to move the insert around, and there should have been plates that covered those prior to installation. The only problem you may have is at the secondaries if they blocked off the air supply at that lower hole. Did they remove the front lower in room air intake box during install? That is a must.

 

[kennyp2339]

Personally I think your leaps ahead just by having a block off plate and insulated liner, the additional insulation wrapped on the outside box of the unit isn't going to help or hurt the performance of the stove as long as all air inlets remain open, plus your climate in Tennessee isn't as violent with cold infiltration as say someone in upstate NY or Minnesota, so the heat being conducted horizontally through the brick fireplace wont be as severe.

 

[webby3650]

Here’s what I did. My Fireplace is on an exterior wall of the home, all stone. We were taking on tons of radiant cold through the firebox, this helped tremendously.
It would be really tough to do this once the stove is sitting in place.

 

[ginkgotrees]

Hogwildz, I will double check to make sure the secondary was not covered. I have seen one of your posts about removing the lower front plate to allow for inside air intake, but I do not recall them removing that and will do so. It seemed easy enough to do myself.

Kennyp, thanks for the enthusiasm. I figured the insulated liner and block-off plate were the most critical. While we don't have the same extreme temperatures as farther north, the chimney exterior faces south and most weather patterns in TN come from the west/southwest. On one hand it gets heated by sun all day, on the other it is the most exposed to wind chill and convective cooling. My thinking was that the old insert was already out and insulation is not that expensive, so go ahead and insulate the firebox.

Webby, that is exactly what I had in mind when I was requesting firebox insulation. You can see from the first photo that we have quite a spacious firebox (didn't realize the luxury of that until I saw regrets on small cubic footage of inserts) which means Roxul insulation around the outside would not be in direct contact and allow airflow to prevent overheating/firing. I am waiting for PE to get back to me if the direct-wrap presents any performance or especially safety hazards, and if so will likely aim for your setup.

One other quick question - I don't think they caulked around the block-off plate. In a post by cableman installing a Drolet model he used silicone caulking around the block-off plate. I am sure this creates a better seal and will plan on this in the future, I just wanted to see if there was a recommended fire-rated caulking to use.

I appreciate all of your feed-back, it is incredibly helpful and reassuring to check these issues to ensure fire safety.

 

[begreen]

Yes, I noted they not only didn't caulk around the block-off plate perimeter, they also didn't flange it on the rear edge (can't see the front edge). The lack of flange will make it harder to achieve a good seal. In your milder climate this is going to be less of an issue.

 

[ginkgotrees]

Yes, I noted they not only didn't caulk around the block-off plate perimeter, they also didn't flange it on the rear edge (can't see the front edge). The lack of flange will make it harder to achieve a good seal. In your milder climate this is going to be less of an issue.

Do you have an image of what the block-off flange would look like? A google search did not yield relevant results.

 

[webby3650]

Do you have an image of what the block-off flange would look like? A google search did not yield relevant results.

Typically the plate would have a 1” return lip all the way around it. Some people use a piece of angle metal mounted to the brick and then attach the plate to that. Either way is ok.

 

[ginkgotrees]

Ah, got it. There was actually a good example in the Drolet install thread, for future readers.

 

[Hogwildz]

A tube of silicone sealant is plenty for around the perimeter of the block off plate. Do not use it around the liner penetration though. You can stuff some rope gasket in there if need be.

 

[begreen]

Do you have an image of what the block-off flange would look like? A google search did not yield relevant results.

There are many examples linked at the end of this article:
https://www.hearth.com/talk/wiki/why-damper-seal-is-needed-block-off-plate-install/

 

[weatherguy]

I thought there was a flange when I looked but my eyes aren't that great looking at small stuff.

 

[begreen]

I thought there was a flange when I looked but my eyes aren't that great looking at small stuff.

There is on the sides but I don't see one at the back.

 

[ginkgotrees]

Thanks, begreen, for the link to the wiki images. I'm still new to the forum and missed the wiki link at the top, so this is helpful.

You are correct that there is no flange in the back section. After talking more with our installer, it sounds like we are the first customers that have asked for a PE insert despite the fact that our installer is the only dealer for PE products in the area. I suspect they also do not create block-off plates with any regularity, hence the lack of proper flange. The rest of the work was pretty good. I have done some metal fabrication before and may just make my own reflective wall plates and create a flange on the back on to attach to the block-off plate. That should both reflect heat back to the room and provide a connector to attach an seal the block-off.

It's interesting, having read the many discussions about installs around here, I would think some of this stuff should be pretty obvious or standard, but I guess some of this more detailed work is just not that common for inserts, especially for the milder TN climate where people do not worry about making complete seals. I still think that's dumb because a big energy sink is loss of cooled air in the summer time.

I am still waiting for a confirmation from PE on wrapped inserts.

 

[begreen]

You could pop rivet some 1" aluminum angle stock to the back edge of the plate and tapcon that to the brick. But in your climate zone I think I would just try it for a season. However, if they failed to close up the upper opening flaps and blocked the secondary intake on the back of the stove they should fix that.

 

[webby3650]

I really doubt PE will approve insulation laying on their product. It wasn’t tested that way, will be the response I’m guessing.

Personally I’d remove the insulation, run a bead of silicone around the block off plate and be done with it. I assume the gap around the edges are minimal? Skip the reflective panels, these inserts don’t get very hot around the jacket anyway.