Questionable dome insulation installation

[indiebands]

Hello again,

The builders misunderstood my drawing of the insulation and structure for my modular oven (admittedly, we do have a language barrier problem since my Czech is not the best and their English does not exist). Around the dome, they put a layer of refractory cement (fine), on top of that they put the insulating blanket supplied with the oven kit (fine), then instead of filling the space between the insulating blanket and the walls of the enclosure with loose vermiculite/perlite, they filled the space with more refractory concrete (a cement/perlite mixture) which appears to have too much water in it to boot.

I have a couple of questions about what to do now.

(1) Cosmetically, the oven enclosure was supposed to be 20cm taller than it is now. Given that the whole enclosure is effectively a (still wet) refractory concrete bunker, it seems that it would be wise to allow the top to breathe since a lot of water is going to need to escape. I was thinking that on top of the existing refractory concrete roof, we could add a wood substructure to support the terracotta roof tiles and leave an air gap between the top of the concrete and the bottom of the roof (perhaps having grates or mesh on the sides directly under the roof to allow airflow). Given the excessive moisture in the dome insulation, is the oven curing process going to take months/years?

(2) I still need to order the super isol boards for insulation of the oven floor (per my Retrofitting under floor insulation thread), but in the meantime, can I start gentle curing fires? I can reinsert one of the floor tiles to be insulation for now, rather than putting the fire directly on the uninsulated concrete slab. Would it help to have a space heater running inside the oven chamber while we are not there (5 days of the week)?

Thanks in advance for your advice.

[david s]

Re: Questionable dome insulation installation

If you have fine weather let the sun and wind do much of the drying for you, while you wait for your floor insulation. Leave the door off the oven as well. if you place your hand inside and it feels really cold then there is moisture there. Do cover it if it looks like rain though. you can try the space heater, but it is an expensive way to dry the oven out. I don't think it is going to take months or years to dry but it might be a few weeks. A hand held to the outside of the oven in different positions tells you a lot. If it is hot then your insulation is wet there. Once dry it should be cool or just barely warm to the touch.

[indiebands]

Re: Questionable dome insulation installation

If you have fine weather let the sun and wind do much of the drying for you, while you wait for your floor insulation. Leave the door off the oven as well. if you place your hand inside and it feels really cold then there is moisture there. Do cover it if it looks like rain though. you can try the space heater, but it is an expensive way to dry the oven out. I don't think it is going to take months or years to dry but it might be a few weeks. A hand held to the outside of the oven in different positions tells you a lot. If it is hot then your insulation is wet there. Once dry it should be cool or just barely warm to the touch.

Thanks, David. The challenge is that the oven is at our weekend cottage, so the opportunities to uncover it during fine weather (as we are having today) are relatively rare. With a breathing roof, I guess it will take longer to dry out than if it had direct sun and wind exposure.