Finally started

[mnl]

Hi everyone

I have finally started a build. When I mean started, it really is only started as I have just started digging the hole for the concrete slab to build the base on.

I'm also trying to finalise my design and would like some advice on the following:

(a) I'm planning on building the base out of 16" x 8" grey blocks concrete filled as per the pompeii oven plans. To support the base I was going to put some fibro sheeting supported by a couple of spans of RHS which is keyed into concrete cored blocks. On top of this will go a cement slab with some calcium silicate board on top. Do I need the concrete slab for structural support or assuming the RHS is close enough together, should I be able to get away with putting the calcium silicate straight on top of that? Also, was planning on using the following for the hearth -->

http://www.claypave.com.au/slab/

. Is this going to be thick enough at 50mm to give me enough thermal mass or should I put something underneath it like a layer of 50mm pavers? Also, does anybody know where I can get calcium silicate in Brisbane (Queensland Australia, not California)

(b) the oven will be a barrel vault. What do I need to do about buttressing the walls in order to withstand the outward force from the arch? I could concrete or refractory mortar them, however this will add significant thermal mass resulting in it taking a long time to heat up. I will at least lay the side walls in a running bond on the flat side, however I'm definitely not a mason, therefore concerned that my craftsmanship (or lack there off) will fail me and my oven!

Any advice appreciated as I want to make sure I have the design sorted before laying a slab. I would hate to lay the slab, build the base and decide I want to change the design but can't as the base size does not accommodate it.

Thanks

Mark

[mnl]

Re: Finally started

School boy error, link fixed.

- Slab

[cobblerdave]

Re: Finally started

Gudday
I noted a ref. to Claypave .... They do a kit for a "tunnel oven" has this influenced you choice of oven?
"Total ceramics" type that into your search, will give you a contact for insulation.
Regards dave

[mnl]

Re: Finally started

Thanks Dave. The barrel style was initially driven by a perception that it Wouk be easier to build than a dome. Not sure this is correct, but at the end of th day, perception is reality. I initially started with Alan Scott plans, but making some amendments such as hearth straight on top of insulation.

I typed in Total Ceramics into search and got a company in Perth called Total Commercil Ceramics. Is this the company you meant or are my google skills failing me?

Regards

Mark

[mnl]

Re: Finally started

Dave - also meant to ask, where did you get your firebricks from?

[cobblerdave]

Re: Finally started

Gudday
Sorry for getting that wrong
Go to Aussie section page 2 and you'll find a thread "suppliers in Brisbane."
Any other help please free to PM me
Regards dave

[cobblerdave]

Re: Finally started

Gudday
Re. Dome oven being hard to built V tunnel oven.
There are some truly awesome builds on here but it dorsnt have to get to complicated or require the use of a bricksaw and complicated tables to achieve a dome. My own oven was built with a brick bulster and angle grinder as simply as it could be. And still strong and functional
Check out Budget build 36" in this section, simple and one of the fastest builds I have seen.
Regards
Dave

[hodgey1]

Re: Finally started

Thanks Dave. The barrel style was initially driven by a perception that it Wouk be easier to build than a dome. Not sure this is correct, but at the end of th day, perception is reality. I initially started with Alan Scott plans.

Mark,

I would have to agree with Dave that the build doesn't have to be crazy complicated.

When I ventured into building my own WFO I was going to build a barrel vault for the same reasons as you. I had never laid a brick and I worried that the round dome "Pompeii oven" would be a impossible task for me. I kept thinking, how do you make a dome with square blocks that wont collapse. After studying and reading a lot online and on the FB forum I came to the conclusion that the round oven was a better fit for me because my main focus was pizza and not baking bread. Also, after reading the plans on this site the Dome build began to make way more sense and became less scary.

I used the standard method described in the Forno Bravo plans and used mostly the full bricks cut in half for the majority of my dome. Once I got about about 6 or 7 rings of the dome completed I realized that I now had gained the skills to step it up a notch and cut a bevel and taper in each brick to tighten up the gaps, but it is not necessary.

I really want to stress not to settle on the barrel/tunnel build because of lack of skill. I believe that just about anyone with determination and some patients can build the Dome. I did and I've never laid a brick prior to this project.

If I can be of any help let me know.

[mnl]

Re: Finally started

Thanks for the feedback.

A couple more questions if I can please:

- I'm planning on doing the foundation slab 6" thick with deeper rat walls. It has been suggested to me that I should put 2 layers of rebar in. Any views or is this overkill? If just one layer, what thickness have you used?

- also, what thickness rebar have you used in your hearth slab. I was going to use 1/2" as this is what the Pompeii instruction have unless I get feedback to the contrary.

If it makes a difference, I leave in Brisbane Australia where it is rare to get down to 5 degrees celsius.

Thanks

Mark

[mnl]

Re: Finally started

I thought I should also post a photo. It is going to be a long project with my lack of progress and also with such good helpers!!!

[hodgey1]

Re: Finally started

You may have the cutest helpers on the planet. I used 1/2" rebar on 12" centers for my hearth slab.

[silvfox]

Re: Finally started

Your helpers will have trouble handling anything bigger than 1/2" rebar and that would be overkill anyway.
Twelve O.C. like Chris says, tie wire the intersections and support so they stay centered in the slab. You could double up vertically on the parimeter for good measure.
John

[mnl]

Re: Finally started

Thanks hodgey1 and John.

I haven't made much progress recently. I got the hole dug, form work, reo cut to go around the pipe a bit over a week ago, etc and now it is just sitting there waiting for the contractor who is doing it. I'm getting him to do the pour that slab as he is here doing other work, but will do the top one myself.

While I have been waiting, I have been trying to gather some materials. Yesterday I got the rest of the grey blocks I need and have a test stack started in the garage. Got some refractory slab (300 x 300 x 50) for the floor and 50 fire bricks (only got 50 while I was there as that made 400kg in the trailer which was heavy enough). The plan for today is to get the rest of my materials like reo, fibre cement sheeting etc.

For those that lay their slab on fibre cement sheeting, how thick did you use? If you used 6mm, did you just support it from below as I did not think it would take the weight (while the concrete is setting)? Alternately, I could use 15mm?

Will post some photos of my (lack) of progress later.

Mark

[chubbybones]

Re: Finally started

Hi Mark,
I think it would be cheaper to use timber than cement sheeting.Easier to cut and you wont have to worry as much about the airbourne fibrous material.If you go for the cement sheeting i'd go 15 mm.
In both cases you'll need some sort of support below if you're doing a 100mm slab.Some 4x2's maybe 300-400mm apart in both directions supported by what ever you can find,i used some blocks and pieces of small timber which i could knock out later to dismantle the whole thing.It's better to be safe when working with a lot of weight.
Regards John.

[cobblerdave]

Re: Finally started

Gudday
I take it your using the cement sheet so that you don't have to remove it later?
Even if this is the case I'd still put some support in. 3 x2 untreated pine would be fine, double up if you don't think they be strong enough. It will make good kindling later .Screw together with chipboard screws and battery drill,leave the heads out so you can get to them later. Don't forget to tape all joints and edges least the cement bleeds through.
Hope something here might help
Regards dave
Forgot to add make sure your screws are pointing in a direction you can get them out later when the slabs on top