Would rebar in dome made out of homebrew would resist steel expansion ?

[MikeDragonDen]

Hi first Pompeii out of an existing wood fireplace front door reuse and top cheminey and want to add some support structure forthe dome made out of homebrew 3:1:1:1 pool sand:hydrated lime: Portland cement and fireclay (midstone fire clay found here https://www.sial-canada.com/en/midst...y-rmids5-group)

Would the rebar steel take expansion and make mortar break ??

[SableSprings]

If you are planning to cast your dome with the rebar in homebrew, I think you are going to have problems. The rebar within the dome will expand significantly more (and more quickly) than the refractory and (IMHO) will crack your oven during the first moderate heat that's applied. David S ( david s ) our resident casting expert will hopefully weigh in here...but he normally recommends stainless steel needles, or fine poly fibers (that melt/burn out) or nothing at all for a cast dome.

It looks like you are putting the cooking surface bricks directly on the concrete support slab. If you do this, firing the oven will pass heat into the concrete as a heat sink and it will be not only difficult to bring the cooking floor of the oven to pizza temperatures, but over time degrade the concrete. We recommend 2" of ceramic insulating board or 4"-6" of 5:1 perlite (or vermiculite) to cement as a minimum between the slab and the oven structure.

[david s]

The industry standard forrefractory reinforcing is melt extract fibres, more commonly called stainless needles.I believe the problem with thick steel bar, apart from that which Mike has described is that the stainless won’t have corrosion problems. Remember that a moist environment plus heat is a recipe for a reaction. If you are building a dome then the structure is self supporting should any cracks occur. The burn out fibres which give the refractory some protection from steam spalling are arguably more important, especially as the needles are quite expensive and make laying up more difficult (they’re not called needles for nothing).