I have double wall stove pipe needs 6" clearence i have 15 to the wall and the 15 from the ceiling 90 elbow. Question when i reloaded today i forgot about the damper fully opened for 15 minutes. The wall was very hot could almost not touch it. I was thinking of getting an 36x52 inperial ul approved wall shield board the board would run right up to the thimble and protect the wall. The ceiling was not that hot through. Do you think this is over kill since the stove pipe only need 6" clearence and i have 15.