In general, hardware is mounted to the facing material, not the firebrick of the refractory core.
For the doors… we recommend making the rough opening in the masonry facing 3/8" larger all around than the door’s “return phalange” (that’s 3/4" total added to width and height). This provides space for the 1/2" ceramic wool we supply to be packed in to the gap between the door and masonry which provides a good seal as well as room for the cast iron to expand.
When setting the door, you want to:
- Cut a piece of the 1/2" gasket material the width of your opening and set it on the bottom of your opening.
- Set the door frame in, level it, and then mark with a long pencil lead the position of the holes.
- Remove and pre-drill with the correct masonry bit (3/16" for the 1/4" masonry screws we supply). Note: you may need to use a metal drill bit to enlargen the holes in the door frame slightly or drill new holes to align with a mortar joint, for example.
- Set the door back in on the bottom gasketing and then insert and tighten screws together gradually, checking level as you go.
- Once the door is secured, cut the rest of the gasketing to length for the other three sides and place into the space between the door frame and the masonry, using your fingers to pack it in. It should be quite snug so that there is no chance of it falling out on its own. If it is too snug, “peel” layers of the 1/2" ceramic wool to make it slightly skinnier. If it is not snug enough, make a shim out of 1/4" ceramic paper to combine with door gasketing.
There are other strategies for door mounting that can be used depending on the hardware and masonry involved:
- Threading the door frame and using bolts
- The “clamp” strategy
- Using threaded rod couplers as bolt anchors as embedding the frame as you go in the facing (including gasketing)
- An old-fashioned manner of using motorcycle spokes (stainless wire with end caps) or wire to tie door frame into masonry.
This strategy can apply to ash box doors also.
For cleanouts, we recommend making the rough opening closer to the hardware’s dimensions and using high temperature silicone to secure the frames. You can use clamps to temporarily clamp the soot door frame to the masonry in its level position while the silicone sets.
We are working on designing a set of masonry frames for the ash door and cleanouts that will make an easy way to create those rough openings.
This is a rough draft for an article that will eventually be written. Feel free to pose questions to further clarify the text and share photos/descriptions from your own experience.