Help for newbie in oz

[robbie55]

I've been bitten by the bug and am keen to get a WFO in my backyard.

There seems to be plenty of info around how to build the slab and the oven itself, (thanks to this forum amongst others) but I'm having trouble with respect to getting some good info on building the base.

If I were to build the base out of cinder blocks for example - do I need to fill every cavity with cement and rebar or just every third or fourth?

I've little experience in laying bricks/blocks but have seen you can get some spacers to assist in getting all the gaps between each course identical, are there any more tips anyone can share for a novice?

I've built a small wall with hebel many years ago and found this easy to work with and cut - are hebel products strong enough to build a base out of?

Any all advice appreciated

[david s]

Re: Help for newbie in oz

You could use Hebel, but it is expensive. Standard concrete blocks are cheaper and have better availability. If you mortar the first course of blocks and get them positioned and level, then you can use a masonry adhesive like Selleys liquid nails-landscape, for the rest. Filling every second void with concrete and rebar should be sufficient. If you use 6" blocks rather than 8" you will save a lot of time and effort because there's way less to fill.

[Mingy]

Re: Help for newbie in oz

You 'dry stack' the blocks - no mortar - then fill. Its a good idea to fill the corners (end blocks) then every second one. Makes it very strong and stable. I actually used polyurethane construction adhesive (PL500) between the blocks, like mortar, but only real thin. Once that sets up, the blocks won't move during the pour.

[cobblerdave]

Re: Help for newbie in oz

Gudday

Like mingy said Can't get easier.....stack the bock up like leggo and fill every
2nd core. Strong simple ....cheap

Regards Dave

PS have you a copy of the Free plans?

[UtahBeehiver]

Re: Help for newbie in oz

Robbie,

Dry stack is the way to go, I did fill every other core although some were back to back fills since I used some 1/2 blocks and wanted to ensure they would not float. My dry stack is documented in my Picassa log. Good Luck

By the way all you Aussies, visited your country last year, lovely country, mostly Sydney and Blue Mountain areas. Need to come back and see other parts.......

[robbie55]

Re: Help for newbie in oz

Thanks very much for all the replies and have had a look at your builds (from the links in signatures).

I think the dry stack is very well suited to my skill level, but is the first course also dry stacked? (that is no cement between the slab and the first row of blocks?)

It might sound silly trying to save a few inches but I live on a small inner city block and plan to put the oven in the back corner - can I build right up to the edge of the slab or is it absolutely essential that slab be larger that the outside of the base?

[Les]

Re: Help for newbie in oz

If your slab is level you could dry stack. If it has irregularities you would want to set the block in mortar (first course only) to get it level. In regard to the size - if you are planning on covering the block with brick, you will need the extra 4 inches. If you plan on a simple render on the block you can get away with it.

Good luck with your build...

[robbie55]

Re: Help for newbie in oz

Thanks Les - answers my question on both counts.

I hope the slab will be spot on level but if not will set the first course with concrete.

I hadn't thought about giving it a brick veneer but as the back will essentially be on the boundary and not seen, building to the edge of the slab/boundary on that side would be preferable, not only to save on valuable space but prevent rubbish and pests from gathering.

[david s]

Re: Help for newbie in oz

"but as the back will essentially be on the boundary and not seen"

Be careful, most councils require you to build 1.5m inside any boundary fence. If you end up with a neighbour dispute (smoke issues?) they would be within their rights to demand you demolish it.
Mine is right up against the boundary fence and I look after my neighbours with pizza and bread passed over the fence, but this is not necessarily a guarantee.

[Mingy]

Re: Help for newbie in oz

Here is an easy way to make 100% sure your first course is level:

Use shims or whatever you have to to make sure the first row of blocks is level. This should be pretty quick and painless.

There is this stuff called 'non-shrink grout'. I don't know what they call it where you are. It is sold in 20kg or so bags and is about 8000psi strength (about 2x concrete). You can mix that stuff from the consistency of milk to almost dry. So mix up a batch which is pretty liquid. Pour enough of it into the first row of blocks so it fills in the bottom. You might have to plug the gaps in the bottom, depending on consistency, so it doesn't leak out. Let it set up, which will be a couple hours, and voila your first row will never move again.

You can do a lot of very cool things with grout.

[brickie in oz]

Re: Help for newbie in oz

most councils require you to build 1.5m inside any boundary fence.

You can build right on the boundary now just as long as the material is fire rated for 1/2 hour, 1 skin of brickwork is rated at 1/2 hour.

Thats from the Building Code of Australia.