Reading the directions ahead of time 
it says to cut off the corners…but don’t discard them…I don’t see anywhere in the directions that says when to use them.
Next. It says in 35 that the back only needs 1 layer and then in 36 it says to add another layer…
Last, I purchased an extra box, so does that mean that I should just follow the same directions twice? 4 layers on top/sides and 4 layers on the back?
Hi Ando443,
I see what you mean. So first let me address the trimmings. You can use them if you wanted to say, insulate the chimney. Thats what I did.
Now my instructions are older so they are a little different I think. Basically brickwood is saying only one layer is necessary for the back. You wrap the oven starting from the front, around the back and finish in the front. Trim the back then complete the single layer for the top. Then go from the bottom of on side to the bottom of the other for the second layer. YOU WILL NOT have enough to do a second layer for the back. 25 ft only covers so much.
But you have two rolls. And if you repeat the process you will have a total 4 layers on top and 2 for the back. Plenty. I did the same. Remember heat rises so that is why the back does not require as much. Hope this better explains what your asking.
Happy building.
Endorsing what Pete said. One of the reasons you don’t throw the scraps away is that they are expensive, and still very useful.
But yes, I had corner trimmings and the square that represents the chimney left over from each box of insulation.
Yes, follow the same directions. You’ll notice that by so doing, you are covering the seams of the first layer with your second layer (and third, and fourth). If you come up short with your top roll, don’t worry if the ends don’t reach down all the way to the brick frame. (You’ll see what I mean when you get there.) Use your corner scraps to insulate the odd areas around the chimney, again because you might come up short.
Good luck!
