Ash box door installation

I am looking at the holes provided on the inner lip of the (classic) ash box door, and wondering how it is intended to be installed. It would seem like the holes being placed on the sides of the frame (like the larger fire box door) would allow the masonry screws/drill to reach in there. The opening is so narrow from top to bottom. Before I drill my own holes in the door frame, thought I would check and see if I was missing the obvious.

Hey Ruth. Originally motor bike spokes were used to attacht the cast iron parts into the masonry. Nowadays there are special tight fitting masonry frames available in which the door is being pushed tight (not sure if this is correct english…)

Hi @Ruth. This is a good question and @Theo.Dubois provides one good solution.

Indeed, as Theo writes, we recently developed sheet metal masonry frames for the Classic Line ash door and soot doors we sell. You can find out more about them here:

The cast iron frames are friction fit into the sheet metal frames and the joint between them is sealed on the inside with high temperature silicone.

Once assembled like this, you can mask the piece and install it as you build the masonry.

I believe you are already beyond this point so, yes, I would recommend that you drill one hole in each corner horizontally to be able to attach the doors with 1/4" (6 mm) shank, 1 3/4" (50 mm) length masonry screws. We place the frame and then trace the location of the holes on the masonry with a mechanical pencil lead. We use a hammer drill to make 3/16" holes. We then place the hardware and drive the screws by hand using a ratcheting 5/16" hex socket. We do this by hand in order not to strip the hole.

It is then important to seal between the ash door and the surrounding masonry. For more technical doors which experience higher heat, this space is sealed using the ceramic wool insulation strips that we provide. The ash door is typically at a cooler place in the heater and can basically be mortared in. The screws help to ensure the strength of it’s installation.

Thanks @max, you use the words I was looking for. Attached a picture of the use of the spokes.

Thank you @Theo.Dubois and @max for your responses. I truly appreciate the information, and since the face of my heater is already completed, I will plan on using the bolting method @max detailed. I was just reading the post about masonry hardware installation (I somehow did not see that before, even though it was right in front of my face, how embarrassing) but there are some extra details in this thread not listed there that are very helpful to me. Thank you so much.

speaking of ash boxes… Max, you were designing an ash box for your masonry heaters. Is it available yet?

Yes, we have ash drawers available: