dew point and moisture

Posted by Douglas

I have finished insulating my oven - I have used a rock wool blanket that is designed for kilns.It is supposed to be water resistant. My insulation is about 4-6 inches thick. my roof is in place and I still have a little opening at the top of the rear gable to let air in and out.

after a few firings I removed some roof tiles top check on things and I found that the top layer of insulation was pooling moisture and was damp.

I suspect that I have driven moisture out of my firebricks(9 inches thick of firebrick at all points) and into the insulation - as my roof does not leak(i tested with paper in a big rainstorm)

As this area in Canada is now cold and most nights the temperature is below freezing I wonder how I can drive the moisture out. it seems to me that the dew point is somewhere in the centre of the insulation layer. That is the moisture evaporates close to the oven but condenses before it escapes the insulation layer - then when the oven cools - gravity has its effect and the moisture settles close to the oven again.

do you think that if i run a fire continuously for three or four days that I can drive the moisture out of the insulation? -or do I have to wait till summer - the warmest days at the moment are 10 degrees Celsius and nights are almost always below 0 - and I am going away for two weeks - so by the time i am back it will be even colder

would removing the roof tiles(concrete tiles) while burning off the moisture help?
will running a fire for three or four days continuously harm the oven?