Fire box doors, sealing

Home Forums General Masonry Heater Discussion Fire box doors, sealing

This topic contains 1 reply, has 2 voices, and was last updated by  yellowcat 2 months, 2 weeks ago.

Viewing 2 posts - 1 through 2 (of 2 total)
  • Author
  • #5643


    Greetings. My 11 year old Masonry heater broke another fire box door seal after being repaired by my local (certified) chimney sweep. (I’m referring to the airtight seal between the metal door frame and the brick facade). The original door seal lasted about 8 years, until the four anchors loosened, most likely from the door expanding and contracting. In the Fall 2017 the four anchors were relocated (re-drilled door frame and face brick) and replaced with 1.5″, center pin type masonry anchors and the door repacked and re-caulked. All was well until this year, where the door anchors loosened again and the door seal opened.
    Should longer anchors be used? What are the recommended type of anchors to be used? Should the door be anchored and resealed with masonry cement? Anything else we should be concerned about?
    Thank you in advance for your expert opinions. This is an excellent site and the information convinced me 11 years ago to have this heater built.



    “Tapcon” concrete screws are the usual method for attaching the firebox doors. The 1/4″ x 3″ to 3 1/2″ hex head would probably be the easiest. But, countersink phillips head would look more professional. Just use the recommended size of carbide tipped masonry drill bit pointed in at a slight angle to pull the door to the inside. If your brick are very hard you might want to use an impact driver to help set them very gently without stripping the hole. But, if you do happen to strip out a hole you might try cutting a thin strip of copper flashing or a length of copper electrical wire (flatting it out with a hammer might help) and use it to wedge the screw into place. If you are not already using it, ceramic blanket is a very good material for sealing doors.

Viewing 2 posts - 1 through 2 (of 2 total)

You must be logged in to reply to this topic.