Harman specified Insulaton as block off - What do you guys think?

[biggins08]

About page 12....Fiberglass insulation as a block off?

http://www.harmanstoves.com/doc/exceptioninsertm.pdf

I ried making a block off plate and I suck at it....

 

[DavidV]

I doubt it passes code most places. I bought the ceramic blanket. 25 feet roll for about 75-80 bucks off ebay. not bad. The blockoff plate was a pain in the butt but I got it done.

 

[stoveguy2esw]

strongly suggest blockoff plate, insulation can get wet and fall back down breaking the seal on the flue. even if i were going to use insulation (which i wouldnt but if i flat out was made to do so , i'd run the liner all the way out and seal at the top as a bare minimum, direct connect without a blockoff plate is asking for trouble

 

[elkimmeg]

Hey hardwoods are you now singing the blues? You fishing me for a response? I will ask Harman when was the last time the recomened a product when its temp range is
not suitable for the application No wonder inspectors can over ride crappy manufacturer's suggestions. don't expect me to sign off that installation also they got 2003 NFPA
cross-sectional code wrong still stuck on 3x the area

 

[biggins08]

No Elk...Not baiting you! It's just funny that they would state that it is ok to do that, don't you think? I am taking another crack at the block off plate this weekend and was reading the manual. Just thought it was interesting...

 

[MrGriz]

Getting the blockoff plate cut correctly and installed is a bit challenging, especially if you don't have a lot of room to work. Remember, the plate can be made in a number of pieces and doesn't have to look pretty. If you have some gaps around the liner, just cut smaller pieces of metal to fill the gaps and cement them in.

I was also wondering if door gasket could be used to provide a tight seal around the liner? Could you use gasket adhesive to hold it to the liner and / or blockoff plate? That sure would make it easier to get a good seal to the liner.

 

[BrotherBart]

Getting the blockoff plate cut correctly and installed is a bit challenging, especially if you don't have a lot of room to work. Remember, the plate can be made in a number of pieces and doesn't have to look pretty. If you have some gaps around the liner, just cut smaller pieces of metal to fill the gaps and cement them in.

I was also wondering if door gasket could be used to provide a tight seal around the liner? Could you use gasket adhesive to hold it to the liner and / or blockoff plate? That sure would make it easier to get a good seal to the liner.

Rope gasket works just fine and reduces the chance of cutting the liner with the sheet metal. That rope gasket is fiberglass by the way.

Of course using tightly packed "flame retardant" insulation for blocking as approved/suggested in a few dozen insert manufacturer and testing lab certified stove manuals ain't half bad either. I don't think people understand that the same labs that do the UL standards testing also have to concur on the compliance of the installation instructions.

 

[biggins08]

I have an Idea of how I am goning to do the blockoff...Just such a tight space! + the liner comes in at a weird angle and is hard to adjust the plate to that angle. I am going to leave a channel for it to move in and put a smaller piece around the liner whic I can attach to the main plate....

 

[karl]

I would cut a piece wide enough for the block off and a few inches too long. Then cut the hole in it where the liner goes. Then cut the thing into three pieces. One cut at the center of the hole and one cut on the side that is too long. Put both end pieces in and then put the center piece in and use a little hammer to push it over so its snug with the liner. Then seal it up