I removed (very carefully) my form a few hrs after laying the shell (no chimney or back) It was on 3/16 shims and when removed the form dropped down and it slid out fine. I could then very easily remove any uncured mortar that made its way between the bricks and form. The structure was/is rock solid, I then built the back wall and chimney the next day. It was much easier to clean the mortar from the back wall bricks with the foam removed.
Hello Matthew, and welcome to the BrickWood forum.
You win first place in our ongoing discussion about how to set up the foam mold for easy removal! That’s the way a bricklaying rockstar would approach this problem, and this method is no muss, no fuss.
It’s also clear that you considered how much height could be added to the mold before it affected the arch structure. So:
Thank you for sharing your method with us, and I hope you’ll post here often. It’s really great to have another Matt here.
That hearth frame is gorgeous! Your elevating idea really paid off. Can’t wait to see the final results.
Still lots of clean up and finishing touches
Wow. Just, wow.
Your oven looks absolutely pristine inside. Wood fires being what they are, it won’t for long, but that’s beautifully done.
Thanks for the tip! I am definitely doing this when I use my form so I can clean up the inside mortar.
What kind of stone did you use for your framing? What dimensions did you use?
It is rainbow sandstone slab material and is 2" thick. I used a portable water saw to cut it to the size I needed to fit the perimeter of the hearth. The stone dealer would probably also cut it but I already had the saw so I saved some money and have some extra pieces for decoration if needed. (The stone is not cleaned in the photos above)
Thanks Matt, So I’m guessing you didn’t need to use too much sand then to fill the remaining void to bring it level with the top of the frame for the firebricks. Would that be a correct assumption? Or did you have to make any adjustments with the insulating layer. Just trying to visualize the difference between a standard brick that’s 3 5/8" in height (the method per the instructions) and the 2" slab. I like the little hangover edge as well.
Its hard to see from the picture but the stone is actually on a 1" mud bed on top of the concrete slab. This helped make up the difference due to the thickness difference. My sand layer was roughly 1" thick. I did recess the insulating layer about a 1/2" lower than indicated (it sits 1/2" below the main hearth level instead of flush when finished) This allowed me to maintain the insulating layer thickness as well as keep everything at the proper elevation. (I would not go much lower into the slab though with the insulating layer as you start giving up some structural integrity of the hearth but the slab is slightly over engineered so I felt comfortable doing this on my oven). I also put some additional insulating cement between the stone slabs and the firebrick hearth to keep heat loss at a minimum. So far it has all worked well, not much heat is lost around the edge or below the slab and the floor temp is consistent when the oven is fired.
Wonderful. That’s really helpful. If you have any more pictures to share of that process that would be most welcome as well. I really like this idea and the look of it. I milled a fallen cherry and plan on using that wood to frame the cement hearth. I think that the slab and the wood together will look pretty nice! Thanks for your helpful advice!
That’s exactly what I am doing to cover the concrete under the stone. I have a few more things to do before its installed but I will post the pictures. I am using Mahogany with a cherry stain on it. Same for my door(s)