used refractory bricks

[fuegos]

Hello everyone my first post , ive been hanging around for a while & i think this is a really great forum , not just for the technical breadth  & depth that the subjects are dealt with but the spirit of sharing & cooperation along with a friendly and respectful attitude.  i didnt see an introduce yourself thread so here goes.
A local water mill is being  renovated into a residence and a large domed bread oven (at least 2.5 M dia) has been demolished.Ive managed to salvage a small amount of the bricks & slabs.The entire structure was built using refractory brick so most of what ive got are intact unburnt , whole ,  3/4 & halfs.The bricks from inside are pretty fragile so ive not botherd with then but i have collected some broken bits for grog.The bricks are yellowish in colour & seem to be made of a fairly fine and uniform material but the floor tiles & some other larger bricks are made of a much coarser reddish material that has larger pieces in it.The floor slabs are 43cm x43cm & about 6 or 7 thick .
My first project is going to be a wood fired oven , a vaulted design , plastered with cob plus insulation.So im looking at relatively  low temperatures compared with a RMH so how do you think the red tiles/bricks will hold up? What do you think of the idea of using the slabs as sides & bricks for the arch?will the difference in size be a problem with expansion/contraction?

[Vortex]

Hi Fuegos, Welcome to the forum.

It's a bit quite in here at the moment as it's summer, should pick up soon as the heating season gets going.

Your plan sounds good, I can't see any potential problems with it. The broken stuff is great for making your own grog, I'd grab as much as you can.

[fuegos]

Thanks Vortex .Ive been reading up a bit more & it seems the slabs are more insulating than the yellow bricks - this probably explains why they were used for the floor of the oven & the flue.As well as the bricks we ve collected a fair amount of rubble.Im not sure whats left but we have about 160 whole bricks & more than a dozen whole  slabs.Im working on dimensions at the moment & will hopefully create a new thread in time.

[belgiangulch]

Nice score fuegos! Anytime I run across used red brick/ firebrick, I snatch them up, even if I don't have a current project for them. My work is with cars and heavy equipment... but my yard makes it look like i'm a brick layer / stone mason.

[fuegos]

so here i am more than 2 years down the road & a lot of water has passed under my bridges.Work & real life has meant that although the base was finished some time ago a slipped disc meant that the work was put on hold & then the autumn/winter temps intervened.
Ive now decided to build a riserless core inspired by Matt Walkers latest outdoor build. Playing around with the bricks ive noticed that some have a tendency to crack when heated quickly - we lined the floor of our conventional stove & they seemed to be quite fragile.Theyve been stored outside under cover & im thinking that maybe they've absorbed moisture ?? so maybe a gradual firing on startup ?
also im planning to render the outside with cob or clay plaster.The objective is still a bread oven firing every 2 or 3 days so a fairly quick warm up is important but retention/storage isnt.