Clay Oven on Verandah

[BackyardPermaculture]

I've finally decided to build my oven - it needs to keep to a fairly tight budget and I've had trouble deciding where to locate it. First major decision was to build a clay oven on a timber base.

It's based on the Better Homes and Gardens design that a few others have already discussed, with the following features:

- Base made from hardwood and treated pine sleepers, mainly because I already had the hardwood lying around.
- Insulation layer of 100mm (4 inch) ACC (Hebel).
- Oven floor will be clay pavers (second-hand, via Ebay).

[BackyardPermaculture]

Re: Clay Oven on Verandah

Today I decided to relocate the oven to the verandah, which is upstairs. The great advantages are:

- Right outside the French doors that come off the kitchen.
- Won't smoke out any neighbours.
- We have a low, almost flat, roof - easy to run the chimney a few feet above the roof line.
- That end of the deck doesn't get used much anyway.


Downsides:

- Not much space to work in - the tiling around the sides will be tricky.
- Very close to the house, so need to be careful with chimney.

Today I moved the base upstairs and re-assembled it. Then I got the fibro sheeting on, and the AAC / Hebel layer. Also set out the pavers to judge the layout - looks like it will be a 30 inch diameter dome.

[Neil2]

Re: Clay Oven on Verandah

In my opinion, your setup does not look robust enough for a masonry oven. My major concern would be the loading on the existing deck.

[Archena]

Re: Clay Oven on Verandah

He's doing clay (cob) not masonry.

That said, they do weigh quite a bit. My concerns would be the house to deck connection - this is where most decks fail. It needs to be strong enough to not only support the oven, but a deck full of hungry friends. If that attachment isn't secure and strong this is going to go very, very badly. Get one of the engineer types around here to help out there (Paranoid? Me? Yep.)

My other concern would be where the feet rest on the deck - that's a lot of pressure on a very small space. You might want to consider putting a board across the deck perpendicular to the board run and under the feet. That will spread the load across several boards and maybe the joist rather than having it all in just four little spots.

Insulation next to the wall is not optional if that's vinyl. Not that it isn't a good plan anyway but that oven will get hot and vinyl can't take much heat. The stand itself is probably fine as long as you didn't skimp on the fasteners.

I'm sure someone will say that pavers won't last as long. They won't but the nice thing about a clay oven is you can tear it down easily if you need to. Much more forgiving than a brick oven in that regard. The tile work won't be, of course. I don't know about the cooking surface, though.

So, what kind of tile are you gonna do? How do you plan to dress the stand?

[BackyardPermaculture]

Re: Clay Oven on Verandah

Thanks for the replies Neil2 and Archena.

I hadn't considered the house-to-deck connection to be honest; that's a very good point and I'll get it checked out. Spreading the weight across the boards is a very good idea too -I'll apply that before going much further.

I think my base itself is pretty strong - the legs are 8 x 3 (inch), and the rails are 8 x 2. There are 4 inch screws holding everything together and a galvanized coach bolt on each leg just in case the screws corrode.

The house is not vinyl, it's painted timber.

I've got some almost-black porcelain tiles I'm planning to dress the stand with.

Cheers,
Mick

[Archena]

Re: Clay Oven on Verandah

Ooh, the tiles sound nice! I bet that's gonna look great!

[BackyardPermaculture]

Re: Clay Oven on Verandah

Our state had a holiday today so I was able to cut all the tiles and the few bricks that needed cutting. The tiles are really nice - someone left them in a shed when we bought our last house; not enough of them to use for a regular project but plenty for an oven!

I've checked out a few more things, and concluded the following:

- The deck-to-house connection is fine; the joists sit on the same bearer as the back wall of the house.
- Decided to sacrifice most of the landing area at the front, and move the whole dome forward on the base. Then I can move the base back towards the end of the deck.
- Also reduced the width of the oven by one brick; brings it to the size of the original plans, about 30 x 26 inches. I did this to leave plenty of room all round for lots and lots of insulation - just so I don't set the house on fire

Cheers,
Mick

[Archena]

Re: Clay Oven on Verandah

Our state had a holiday today so I was able to cut all the tiles and the few bricks that needed cutting. The tiles are really nice - someone left them in a shed when we bought our last house; not enough of them to use for a regular project but plenty for an oven!

Cool! My favorite kind of supplies - free!

I've checked out a few more things, and concluded the following:

- The deck-to-house connection is fine; the joists sit on the same bearer as the back wall of the house.
- Decided to sacrifice most of the landing area at the front, and move the whole dome forward on the base. Then I can move the base back towards the end of the deck.

- Also reduced the width of the oven by one brick; brings it to the size of the original plans, about 30 x 26 inches. I did this to leave plenty of room all round for lots and lots of insulation - just so I don't set the house on fire

Cheers,
Mick

Awww, come on - no one's burned down a house around here. Don'tcha wanna be the first?

[BackyardPermaculture]

Re: Clay Oven on Verandah

Something I'm not too keen on being the first to do!

[Neil2]

Re: Clay Oven on Verandah

Don't build an oven on your deck.

Do a google search on "deck collapse".

[dmun]

Re: Clay Oven on Verandah

I have to agree. One of the links in Neil's suggested search is:

http://www.mosbybuildingarts.com/blo...deck-collapse/

Lots of scary pictures. It seems that people are killed every year in deck failures.

The safe method is to build from proper footings on the ground next to the deck. I know it's a lot of masonry, but haven't you always wanted a brick garden shed?

[Neil2]

Re: Clay Oven on Verandah

"The safe method is to build from proper footings on the ground next to the deck. I know it's a lot of masonry, but haven't you always wanted a brick garden shed?"

And you will still have the use of that part of the deck that would be taken up by the oven.

[Neil2]

Re: Clay Oven on Verandah

"It seems that people are killed every year in deck failures."

Decks are not built to the same loading standard as inside floors and the connections are exposed to the weather and thus deteriorate with time. Worst still, many decks are built by homeowners with no building permit, therefore no inspection, therefore an accident (and lawsuit) waiting to happen.

[BackyardPermaculture]

Re: Clay Oven on Verandah

Lots of scary pictures

You got that right!

But in this case, I'm increasingly confident it's OK based on the structure of the deck and the forecast weight of the oven.

The weight of the oven should not be more than the weight of 4 or 5 adults. My oven will be a slightly-larger version of this one (but with the chimney OUTSIDE the door); the dome will contain less than 150kg (300 lbs) of clay/sand, and I estimate a total weight of 350kg.

The thing about all of the decks in those pictures is they were attached to the back of the house. My deck isn't at all like that - the joists come right through from the house, and the back wall of the house sits on the same joists. I really can't see that 350kg of oven should be a concern on there.

Cheers,
Mick

[BackyardPermaculture]

Re: Clay Oven on Verandah

Decks are not built to the same loading standard as inside floors and the connections are exposed to the weather and thus deteriorate with time.

That's probably my biggest concern with it, actually.