Can I Insulate Chimney Opening?

[Jsunv]

Question -- this is my second winter in our home. I have noticed and can feel considerable drafts coming from the chimney and through the pellet stove insert sides, bottom, etc. I pulled out the pellet stove to take a look in the fire box and noticed that the prior homeowner attempted to insulate the chimney/flue opening but didn't do a very good job. I want to make sure this is something that i CAN do and is not a fire hazard etc. with the pellet stove insert. I assume it shouldn't be as the vent pipe is for intake and shouldn't get hot etc.

I'm new to all this and want to first resolve the incredibly cold drafts coming through the pellet stove insert putting extra work on our geothermal heat. I attached a picture of what the vent pipe and chimney insulation currently looks like. Obviously there are huge gabs and all the cold air is pouring in...

What's the best way to seal this? Any type of insulation work?

 

[alternativeheat]

Question -- this is my second winter in our home. I have noticed and can feel considerable drafts coming from the chimney and through the pellet stove insert sides, bottom, etc. I pulled out the pellet stove to take a look in the fire box and noticed that the prior homeowner attempted to insulate the chimney/flue opening but didn't do a very good job. I want to make sure this is something that i CAN do and is not a fire hazard etc. with the pellet stove insert. I assume it shouldn't be as the vent pipe is for intake and shouldn't get hot etc.

I'm new to all this and want to first resolve the incredibly cold drafts coming through the pellet stove insert putting extra work on our geothermal heat. I attached a picture of what the vent pipe and chimney insulation currently looks like. Obviously there are huge gabs and all the cold air is pouring in...

What's the best way to seal this? Any type of insulation work?
View attachment 147256

Roxul insulation is the suggested material to use, basically fireproof. And yes you can and probably should insulate there, pack it tight. Most people would also use a metal plate to hold it up in place. If you are getting that much draft though, is the top of your chimney capped ? It should have a metal cap up there with chase hole for your vent to exit out of, then a rain/termination cap on the vent itself . That chimney top dressing in itself generally pretty well stops the draft, though cold could still emanate out a bit. Best deal, cap the top stuff the bottom with insulation on a plate..

 

[Lake Girl]

What brand of pellet insert? If you do not have the manual, you should be able to get it on-line. They usually detail the install procedure. Commonly, the damper is removed and a plate installed for the exhaust to run through. Insulation (Roxul or similar) is installed on the top side of the plate.

Keep us posted...

 

[CaptSpiff]

Question -- this is my second winter in our home. I have noticed and can feel considerable drafts coming from the chimney and through the pellet stove insert sides, bottom, etc. I pulled out the pellet stove to take a look in the fire box and noticed that the prior homeowner attempted to insulate the chimney/flue opening but didn't do a very good job. I want to make sure this is something that i CAN do and is not a fire hazard etc. with the pellet stove insert. I assume it shouldn't be as the vent pipe is for intake and shouldn't get hot etc.

I want to comment on your last sentence above: Your flex-vent pipe will definitely get hot as it is transporting the combustion exhaust gas up and out.

You need to have a full picture of what you got before you proceed. Some quickie installs shove a 5' flex pipe from the back of the insert up past the damper and just into the chimney flue. Then rely on natural draft to take it the rest of the way up and out. Make sure you don't have that type of install.

That flex pipe should go completely to the top of your chimney opening. There it should be supported, as Alternativeheat described, by a chimney Top Plate and then by a Cap.

ex: (broken link removed to http://www.rockfordchimneysupply.com/rigid_liners.php)

Once you verify that you've got those basics, then you can begin the effort of insulating and installing a good damper close-off plate. Good luck.