My intention is to build a hollow concrete cylinder for a fire pit like this:
There are a few people who have done this by using steel sheets bent in to shape with supports between, but I would prefer to use just pure concrete.
The only trace I can find of this having been done is that picture from Pinterest, but there's no link to the build, so I'm reaching out to you guys. My idea is:
- 2 Concrete column formers (I think they're called sonotube in the US), 1 approx 600mm diameter x 500mm length and 1 approx 400mm x 500mm length
- Place smaller one in bigger one
- Pour concrete
- Peel off the column formers
- Cook food, drink beer, hi five.
A few questions that the UK suppliers can't answer:
- Is 200mm thickness enough to support its own weight and contain a fire?
- Can I actually use column formers in reverse (i.e. the inside one)? I'm not as concerned about the finish on the inside, but do want a perfectly round shape
- Is there a simpler way to achieve this shape?