Block Off Plate

One of the things they just don't seem to do in my neck of the woods is the block-off plate. Every stove installer I have spoken to either thinks it is just for sealing off an unused fireplace, or, if they know what it is, they say they don't do many of them.
When I had the Alderlea insert installed, I knew precious little about stoves. I know that they stuffed some roxul down the outsides of the liner, and some of the damper throat had to be cut away to accomodate the fit.
I am thinking about having a retrofit done, if I can afford it. I want to know what else I should know to ask, as I have a feeling they will not offer any practical advice.
I have yet to hear anyone complain that a block off plate was of no use and did not improve the burn. I am in Northern Maryland, planting zone 6b, if that is any help; do I absolutely have to have an OAK? That could be a pricey pain, as the chimney is on the outside and is made, as is the entire rancher, of stone.
Any advice?

 

You can buy a piece of sheet metal at home depot and make one easy enough, it did make a difference in my case, cost is under 10 bucks and you need tin snips, probably a box of bandages too.
If you're not having problems now I wouldn't think you'd need an oak.

 

When I did a reinstall I found that although the installers insulated down below at my insistence they actually put the Roxul on either side of the chimney but not front and back so there was still major gaps. In addition the whole smoke shelf was empty. Really it was a joke. They wanted to use fiberglass up top only so I guess it was better than what they usually do.

Anyway, I suggest doing it yourself and not relying on these guys. Half the time they're telling you it's unnecessary and they don't really know what your trying to achieve. They just want to get in and out. On my reinstall I had the company come out and pull the insert and told them come back next weekend. Over the week I swept the chimney, insulated to my hearts content with Roxul, insulated the back of the fire box and then added a proper block off plate. I also added 3 layers of Durock to insulate the floor and raise the unit. Co came back and reinstalled.

It made a nice difference and I know its done, at least to my satisfaction. My top temp now easily runs 150-200 hotter than before. Secondaries light off earlier and burn better. IR reading of the brick on the outside at the fire box level is now only a few degrees warmer than ambient temp. Before, in that same spot, brick was warm to the touch (like 80!).

It was cheap enough. Get some Roxul and really stuff it as high around the chimney as you can then completely fill the smoke chamber. Make up your plate and cut Roxul layers to lay on top of the plate and fasten it in. Fill the gap where the chimney passes through the plate with more insulation and seal the plate to the brick with furnace cement or high temp silicone. If you have an exterior chimney and the room, insulate the firebox with Roxul. A layer of Durock over the Roxul would be even better but I didn't have the room in my case as it's a tight fit. Just be careful leave some space and not block air intake.

 

I spoke with the original installer earlier, it doesn't sound like he knows what to do. I will take jatoxico's advice, prolly this summer, but I will probably have my guy fasten it, as I don't have the proper tools, strength or technique.
By "sheet metal", do you mean flashing?

 

Excellent. Thanks!
Flashing is the stuff you put around the base of the chimney so the water flows away. It might very well be the same product...
http://www.homedepot.com/b/Building-Materials-Roofing-Gutters-Roofing-Roof-Flashing/N-5yc1vZaqp7

 

Couldn't help myself!
Yes, flashing is the same as sheet metal...called flashing only because of it's application.

 

We can't take you anywhere.

 

You both realize that I will not be able to walk into Home Depot and purchase this with a straight face...

 

Now, does anyone know how to crease this material without a sheet metal brake?

 

I used vise grips and other hand tools. It didn't come out as pretty as some others but you'd never know it now. They sell vise grips with wide jaws for welding etc that would work even better. Got a Harbor Freight close by (they ship) too).

Make up a cardboard mock-up for fitting. Once you get that right reproduce with the metal sheet.

 

Thanks!!

 

Use those pliers and a 2 x 4. I had a 2 piece plate I made when I had my insert but made a new one piece with the new stove, I always make a template out of cardboard then trace it onto the sheet metal.