First attempt at wfo - mezzo 76

[jonh]

Hi all, firstly what a great forum - registered a few days ago and spent ages looking through people's projects... Lots of inspiration!

I'm just about to embark on a project of installing a mezzo 76 modular oven from the stone bake company. It's a cheat I know you probably all built your own but my diy skills are limited - built a patio and wall last summer but v basic and lots of errors 

My first real question is that of foundations - I see so many ovens being built just on slabs or an existing patio, or even just on the ground. Surely this isn't enough?

I was planning in putting some foundation down but wasn't sure of depths etc - wondered what the experts on this site thought? I see some people dig out a square and fill with concrete but I wonder if this is a bit overkill...

Then my rough plan is of breeze blocks, concrete lintels across the top, thermal blocks laid flat, put the mezzo base on that, dome, then chicken wire, render and paint. SIMPLE! 

I just don't want all the effort (and cost!) to go to waste if the whole thing falls apart at the base... The mezzo is 200kg in total!

Thanks in advance,

Jon

[mattyb]

Apr 30, 2014 21:37:19 GMT jonh said:

Hi all, firstly what a great forum - registered a few days ago and spent ages looking through people's projects... Lots of inspiration!

I'm just about to embark on a project of installing a mezzo 76 modular oven from the stone bake company. It's a cheat I know you probably all built your own but my diy skills are limited - built a patio and wall last summer but v basic and lots of errors 

My first real question is that of foundations - I see so many ovens being built just on slabs or an existing patio, or even just on the ground. Surely this isn't enough?

I was planning in putting some foundation down but wasn't sure of depths etc - wondered what the experts on this site thought? I see some people dig out a square and fill with concrete but I wonder if this is a bit overkill...

Then my rough plan is of breeze blocks, concrete lintels across the top, thermal blocks laid flat, put the mezzo base on that, dome, then chicken wire, render and paint. SIMPLE! 

I just don't want all the effort (and cost!) to go to waste if the whole thing falls apart at the base... The mezzo is 200kg in total!

Thanks in advance,

Jon

Hi Jon

I did the same (cheated and went down the modular route). I actually have the Primo 60 from Stone Bake.
Have a look at my build thread ukwoodfiredovenforum.proboards.com/thread/1559/wigan-build

No such thing as overkill when planning foundations / base, my primo dome was a 3 man lift so needed something solid to keep it secure.

I'd never laid a brick prior to this build (youtube tutorials mostly), so you will be fine.

Any advice needed about the oven, just give us a shout.

Cheers
Matt

[cannyfradock]

Hi Jon.....welcome to the forum.

Your concern over the foundation is justified.....and good advice btw from Matty.

Many of our members have installed one of Laura's (stonebake) ovens. She's always had excellent feedback on the forum.

You may see many support walls (on the forum) built on top of existing patio's or paved area's. As long as you know that the correct substrate has been laid....and "wacked" before the laying of the top surface (patio, concrete pavers etc) then the surface will be fine to lay on. If not, then you must remove the top soil or loose compound, lay some aggregate and pour your own concrete slab....minimum 4" with some steel mesh incorperated.

Your build plan sounds fine. I am doing a very similar design for my support walls as you in my current build... ukwoodfiredovenforum.proboards.com/thread/1811/kate-humbles-90cm-pompeii-monmouth ......the only difference is I have arches where you have lintels (I'm casting the support slab also).....otherwise, although a different design the build and construction will be exactly as yours.

All the best with your build....

Terry

[jonh]

Thanks for the info both, much appreciated!

I have no side access to the garden (imagine getting 200kg of oven and hearth through the house - not fun!) so I want to reduce the amount of cement etc too...

Think I'll go for a proper base as per your advice though, and do what Mat did but half the size, enough to support just the oven.

I do want to build a wall to either side of the oven but will build trench foundations instead to save on materials.

Another question if I could - how come you didn't put a dpc under the blocks? I know there was a dpc membrane between gravel and concrete but I thought you needed a dpc on blocks too - or is that overkill?

Lastly - the gravel under the dpc before the concrete - is that wackered down first?

Thanks again!

[mattyb]

With regards to the omission of DPC on the first layer of bricks, this was an over-sight and something I only realised once I'd completed 2-3 layers up! A proper 'doh!' moment!!

However had no issues with rising damp and you know how wet this winter has been, so fingers crossed!

Re: gravel. Didn't whacker down, just skimmed level and poured concrete!

Anything else, just shout.

Cheers
Matt

[jonh]

Thanks Matt,

Couple of other questions if I could!

I built my base over the weekend (not level, too much water and footprints where my daughter thought it would be funny to run over as it was setting but it's great apart from that!) so I'm ready to start with the frame.

- I've got some spare engineering bricks so thinking of laying 2 courses of this as the dpc, then 7n concrete blocks - I assume no issues with doing this? I know athe oven will be heavy but engineering bricks can build houses, right?!?
- The arch. How on earth do you cut the bricks accordingly - I've searched but not found any 'how to' guides. Also I guess you need fire bricks and fire cement to attach to the modular oven?

Thanks and sorry if these questions keep getting asked!

Jon

[mattyb]

Jon,

I still have my Primo 60 in its core format at the moment, looking to insulate it during the summer (if we get nice weather for a couple of weeks), so will look at your thread with interest!

Cheers
Matt

[cannyfradock]

May 6, 2014 18:58:43 GMT jonh said:

Thanks Matt,

Couple of other questions if I could!

I built my base over the weekend (not level, too much water and footprints where my daughter thought it would be funny to run over as it was setting but it's great apart from that!) so I'm ready to start with the frame.

- I've got some spare engineering bricks so thinking of laying 2 courses of this as the dpc, then 7n concrete blocks - I assume no issues with doing this? I know athe oven will be heavy but engineering bricks can build houses, right?!?
- The arch. How on earth do you cut the bricks accordingly - I've searched but not found any 'how to' guides. Also I guess you need fire bricks and fire cement to attach to the modular oven?

Thanks and sorry if these questions keep getting asked!

Jon

Jon

I'll try to answer your questions.....I emphasis..try.

I always go overboard when thinking ahead of any damp issues. Engineering bricks are fine, but I would lay a piece of 4" plastic (DPC) on top of the engineering bricks, then lay your blocks on top of this. My current build may explain this better..
ukwoodfiredovenforum.proboards.com/thread/1811/kate-humbles-90cm-pompeii-monmouth

Don't worry about your base being not so level....you can bring your walls up level with a bit of thick mortar on one side and less on the other.

You can cast a re-enforced concrete slab on top of your walls to take the oven.....or you can lay some re-enforced lintels on top of your walls.

The Arch....It looks like the Mezzo 76 comes with an external arch....if you wanted to add a cosmetic brick arch to the front of this .....use clay bricks and an arch former...... normally there is no need to cut any bricks and there is no need to use refractory mortar outside of the dome ...I'll find some links of threads that show this process if this is what you want.

Stone bake/Laura has excellent feedback for her products on the forum......if in doubt, first port'o'call is to ask for her advice.

Terry

[jonh]

Thanks both again. If it stays dry this weekend will try and finish my base then start building...

Terry, been looking through the forums on how to set the lintels, came across this pic. Do you happen to have any other pics of this build?

ukwoodfiredovenforum.proboards.com/search/results?display_as=0&page=4&what_at_least_one=Lintel&who_only_made_by=0

I can't seem to work out how you'd build the lintels into the breeze blocks safely to ensure its stable.

Sorry you must get this all the time with newbies :-) the stone bake company sell cubes to sit the oven on so I assume it doesn't need much support. Want to be safe though!

Thanks

[cannyfradock]

Jon

I've had a look at my own pics archive and can't find any more pics to help you....sorry.

Problem for me is that all my builds are different.....basic principles stay the same but even members builds seem to never be alike.

On the link that you posted I used lintels on top of a temporary timber structure. The idea was that the whole oven structure would be lifted with the aid of a fork lift truck and be set on a permanent base. In your case.....you have perhaps the support walls in place so you need to bed the lintels down a little mortar. The important factor if you're laying thermolite blocks on top of then is to get the spacing correct. If you look back at my picture you will see that each thermolite block "on flat" lays on 3 lintels so each block is supported on either end and the middle.....the gaps between are so minimal that the structure will be able to take the weight of a Clay oven.....in my case.......or a modular oven...in your case. If we are talking about a large domestic Pompeii oven////and perhaps twice the weight I would suggest a re-enforced cast concrete slab.

Terry

[jonh]

Ok so it's been a while since I updated due to weather / holidays / children etc!

I'm close to finishing the walls now, and thinking again about whether to use lintels or a concrete base for the modular oven to sit on.

Up until now I've thought lintels would be easier, but reading more I'm concerned they won't hold the pizza oven. If I've gone as far as putting a proper foundation in etc I'd hate to see it all fail at the last hurdle!

I've seen a few posts about pouring a base, needing rebar etc (basically just like the foundation base I assume?) but do you know off hand of any posts that show in detail how to prepare one? I found one by zoupy that was quite good but it doesn't show how to prepare a frame to pour the concrete in for example!

Any advice appreciated - or indeed thoughts on whether a concrete base is superior to the lintels, or if lintels would do!

Thanks
Jon

[zouppy]

Jon

I thought about pouring the platform but decided against due to the need for shuttering etc and not sure I could do that well. Decided to use concrete lintels, laid across like rafters, spaced so that they would carry concrete blocks laid on their sides (no martar required, just tightly packed together). This is a very strong structure! I then created a container for my vermicrete by placing a town of bricks around the outside. Then filled in the space in the middle with vermicrete. Built oven on top of that - its a big thing and it aint going anywhere. Dead easy and very strong. FYI I am no building expert.

Hope that is clear but if not then give me a shout.

Z

[jonh]

Thanks zouppy.

Think I'll go with that then - my original plan of lintels.

Did you get any special type of lintel?

Think I'll go lintel, thermalise blocks then I liked your idea of a course of bricks as edging for vermiculite... That should then be enough to plonk the oven onto.

Need to get some more blocks first - seems 440x225x215 is rare and everyone seems to be out of stock!

Sure I'll be hassling you Ina week or so's time!

Thanks again

[zouppy]

I bought the smallest reinforced concrete lintel (about 6x4"). They come in various lengths but you can cut easily with an angle grinder. Z

[jonh]

Ok so I'm finally getting somewhere - base done, walls and lintels almost done... Just need some nice weather to crack on!

thanks zoup for the lintel advice btw...

couple of questions - 

1) what type of brick would I need for an arch? If I leave a gap than use fire cement between arch and oven, can I use any brick? I want grey but can't find grey firebricks anywhere.
2) can you really use standard insulation for the dome? Surely that's not as heat proof as we need?