Moved into a new home and I noticed something about my fireplace. I have a large brick enclosure that surrounds my wood burning fireplace and when I was up in the attic I noticed that the space surrounding the fireplace between the walls is wide open to my attic. I could fit down in the space. I was spraying cellulose insulation and was about to fill in the gaps but stopped. Should I seal these cavities in or is there a need for the gaps?enter image description here

  • Im not sure what gaps you are talking about but you need to get that blown in insulation out where the fireplace is. Use a shop vac and suck it up. Build something to stop insulation from falling in with a lid and you can put batt insulation on top. It is probably a zero clearance fireplace but I would not feel comfortable with insulation and who knows what else falling into there.
    – Justin K
    Mar 16, 2014 at 21:01
  • Blown in insulation should not be touch stove pipe either. Roxul insulation batts can touch it so if you want to wrap it with that first then let blown in insulation touch that.
    – Justin K
    Mar 16, 2014 at 21:13

1 Answer 1


Usually, no combustible materials are to be placed within 2" of fireplace vent pipes or chimneys. We usually use something called Rockwool in these instances.

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