Opening the kiln after the first firing

Since moving to St.just almost two  years ago I have been working towards establishing my own kiln. Luckily I have been able to fire with Michel and use his kilns over these past two years and I am grateful for his support during these times. I am happy now I can fire at home and experiement withmy own box of flames. I am happy with he first firing although the kiln was so damp the first few hours of the firing produced much steam which was worrying, also the firing was stalled later and it took 15 and a half hours to fire due to different factors. on unpacking the kiln I found the problem in the exit flue, the brick work I made had collapsed on one side producing too much flue to the back of the chamber, I had to build it with soft brick but will repair it with Firebrick or kin shelf.