After 5 years, cracked shell...

[Kiwi_in_canada]

[ATTACH=CONFIG]n391090[/ATTACH] So after about five years I'm finally biting the bullet and doing something about the cracks.... Currently got it stripped of the red shell, brushed the dust down, and have a fire going now to dry out moisture. Forecast is looking great and dry for the week. Hoping a couple thin coats of mortar to smooth out the surface and then a coat of Dryvit product for weather protection. Thoughts??

[david s]

I cracked the outer shell on the fourth and fifth oven I built and put it down to wet vermicrete creating steam pressure build up. I now always do the drying fires after the vermicrete layer, then when quite satisfied it's perfectly dry add the outer rendered she'll. I then wrap the whole oven in cling wrap to hold the moisture in that outer layer for a week to enhance its strength. Finally seal over that layer when thoroughly dry with some waterproofing compound.

[david s]

Use some reinforcing in the outer layer of render. Chicken wire is the usual method, but I prefer random fibres in the mix cause it's easier than trying to get the chicken wire in the centre of the layer. If doing chicken wire I find it best to place pieces about one square foot as you go, overlapping them slightly. Start from the bottom and work up.