You need to protect your oven and this time I decided to render it, basically covering the whole things with a mortar fix. I won’t deny this was a little tricky, but not hard. The issue you have is the insulation is just a blanket, so easily moves when you touch it. The render needs to be able to grip on something, so get around this problem you cover the whole oven in chicken wire. Cheicken wire is very easy to handle and easily molds into the shape you want.
As you can see I used classic chicken wire, but I would use that next time. Personably I wouldn’t call it chicken wire as it is too weak to protect chickens and foxes can easily bite through it. For this job you want something a bit stronger, and with smaller holes. I struggled with getting the render to grip the wire, and had to manually put the render on by hand.
I didn’t worry about making the perfect shape or making the render look symmetrical, I just let it do its own thing. I think it all adds to the rustic charm and looks perfect in the garden. Once done leave it to dry, and you are then ready for the next stage.