Insulating around Direct Vent Fireplace

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CCIE

New Member
Nov 14, 2015
3
NC
Hello,

I just had a new gas insert installed in my home and it sits in a corner chase on an outside corner in my house. When the new fireplace was installed, the installers said they could insulate my outside walls behind the chase, because they were not insulated... only the 45 degree wall the fireplace is sitting in. However, they used fiberglass bat insulation with the paper facing towards the inside of the house, and now I'm concerned about this being a fire hazard. I believe if a piece fell down on the pipe of top of fireplace, it could be bad news.

The chase has been sealed back up, so I may have to get access to it by removing the outside siding, since I really do not want to cut another hole in the sheet rock. I'll try to add a picture shortly.

Thoughts? Thanks!
[Hearth.com] Insulating around Direct Vent Fireplace
 
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Hello,

I just had a new gas insert installed in my home and it sits in a corner chase on an outside corner in my house. When the new fireplace was installed, the installers said they could insulate my outside walls behind the chase, because they were not insulated... only the 45 degree wall the fireplace is sitting in. However, they used fiberglass bat insulation with the paper facing towards the inside of the house, and now I'm concerned about this being a fire hazard. I believe if a piece fell down on the pipe of top of fireplace, it could be bad news.

The chase has been sealed back up, so I may have to get access to it by removing the outside siding, since I really do not want to cut another hole in the sheet rock. I'll try to add a picture shortly.

Thoughts? Thanks!
View attachment 166934
Anyone have any feedback about the insulation installed this way inside my fireplace chase? Thanks!
 
That SHOULD have been covered with drywall & taped to seal it, just to keep cold air penetration to a minimum.
Your NC climate isn't nearly as severe as what we get up here in NY, so it may not be as effective.
As long as the Kraft paper meets the CtC specified by the vent manufacturer, & is fastened securely to the framing members in the wall, you should be OK. I would still install the drywall if it was MY home.
 
Hello,

I just had a new gas insert installed in my home and it sits in a corner chase on an outside corner in my house. When the new fireplace was installed, the installers said they could insulate my outside walls behind the chase, because they were not insulated... only the 45 degree wall the fireplace is sitting in. However, they used fiberglass bat insulation with the paper facing towards the inside of the house, and now I'm concerned about this being a fire hazard. I believe if a piece fell down on the pipe of top of fireplace, it could be bad news.

The chase has been sealed back up, so I may have to get access to it by removing the outside siding, since I really do not want to cut another hole in the sheet rock. I'll try to add a picture shortly.

Thoughts? Thanks!
View attachment 166934
Anyone have any feedback about the insulation installed this way inside my fireplace chase? Thanks!
That SHOULD have been covered with drywall & taped to seal it, just to keep cold air penetration to a minimum.
Your NC climate isn't nearly as severe as what we get up here in NY, so it may not be as effective.
As long as the Kraft paper meets the CtC specified by the vent manufacturer, & is fastened securely to the framing members in the wall, you should be OK. I would still install the drywall if it was MY home.

Thanks, I think its just best to get back in the chase and install unfaced or remove, since the wall the fireplace is in is already insulated. I'm more concerned about the paper being combustible if it falls against the pipe. I'm sure my fireplace installer will have a different opinion though :)
 
I share your concern. It it accessible to install some sheetrock, even the 3/8" thin stuff would help.

I see some staples securing the paper to the studs, but not nearly enough. I've seen some "future projects" which penetrate an outside wall and wind up pushing the bat insulation out of the stud cavity. Wouldn't want that to happen here as it would fall onto the pipe.
 
I would have used unfaced batts, poly and sheetrock. With the poly sealed around the edges and then the sheetrock mud and tape. Like what daksy said
 
I just went through this and in the end, although not really necessary, I was happy that I went with Roxul (rock wool) insulation and 5/8" type X sheetrock. The difference it made (versus just fiberglass insulation with no sheetrock) was night and day.
 
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