Starting 42" NW Pensylvania

[hodgey1]

I've been researching for months and trying to convince myself that having never laid hand to a trowel wasn't a problem. Now, I believe after pouring over all the information here and meeting a builder "Boylanta" in the forum whom so graciously invited me to dinner to learn from him, I'm ready to go! I hope?

I am going to do my best to do half as good a job as Boylanta has, what a work of art. As I proceed I will be posting pics and please, any advice or information input is very much appreciated.

So far I have decided to build a 42" oven on top of a existing retaining wall I built a few years ago. I have also decided to cut the floor with the soldier on the exterior and "if I can master it" i'll cut each brick with a bevel and taper to minimize mortar and a cleaner interior look to dome. I'm still struggling with the inner arch, should I precut the upper arch bricks with a taper to join the rings better and if so, what angle?

The help from members here is invaluable, being able to see Boylanta's jig for cutting the bricks and his finished product has been a serious resource that without it, I'd only be a dreamer, whishing some day to afford to pay someone to build me a wfo of my own.

[boylanta]

Re: Starting 42" NW Pensylvania

hodgey1,
Good start, keep posting the updates.
If you have any questions, just ask. There are many willing & able helpful hands around this forum.

As far as the inner arch...
I found that (after the 1/2 soldier chain) using an inner arch template helped immensely. This allows you to test the fit of each brick, if you decide the taper the inner arch bricks. Tapering the bricks will result in a more uniform mortar joint. Once you start cooking, the inner arch will always be completely black, so you'll never see the joints, but that's up to you.

Here's pics of mine during the phase you're referring to...

027 - shows the oven floor w/ the first chain mortared in place. I then began the inner arch.

030 - shows the inner arch base & flared landing, as well as the inner arch template. Don't make the same mistake I made the first attempt at the inner arch: make sure to shim your template to the appropriate height so you can remove the arch straight down, not side-to-side, which will likely ruin your inner arch (speaking from experience).

031 - shows tapered inner arch bricks, ready for mortar. Don't make the same mistake I made in the cutting phase. Notice how the outside facing inner arch bricks have a 45 degree chamfer? This will not allow a good seal for your archway, if you decide to use a door for baking. Ruining my first inner arch ended up being a blessing in disguise, so I could correct this the second time around.

032 - First inner arch mortared in place. Again, this shows the incorrect chamfer of the doorway.

095 & 097 - show the inner arch from the 2nd attempt. Notice the non-chamfered bricks.

I'm by no means an expert, this is just what worked for me.

[boylanta]

Re: Starting 42" NW Pensylvania

hodgey1,
How did you reinforce the retaining wall again?

My guess is that your concrete hearth will weight 1000-1500lbs, with 1500-2250lbs of firebrick (7.7lbs/brick for the Alsey Jet-DP).
That's without any exterior finishing.

[hodgey1]

Re: Starting 42" NW Pensylvania

Each one of the retaining wall blocks weights in at 1600lbs, it's a product called Redi-Rock blocks. The dimensions for each block are 46" wide and 28" deep and 18" reinforced concrete thick. The blocks interlock like legos.

So, i made a "swag" that if you can stack multiple additional courses of 1600 lbs redi-rock blocks that it will manage the aditional weight of the oven. I will be cantilevered over the front of the blocks by 7" and I will be spanning two of these blocks with the width of the hearth. I also excavated 12" below the top of the back of the blocks the additional depth of the hearth and back filled with washed stone tamped with silt fabric for support and drainage underneath the hearth.

So, I hope that is all going to be good. The wall has been in place for 6'ish years and does not move. It has a fabric protected washed/crushed stone footer with a drain.

[boylanta]

Re: Starting 42" NW Pensylvania

Wow,
I looked those up...they're massive.
Certainly will be more than sufficient.
Good luck & keep the updates coming.

[mrchipster]

Re: Starting 42" NW Pensylvania

Each one of the retaining wall blocks weights in at 1600lbs, it's a product called Redi-Rock blocks. The dimensions for each block are 46" wide and 28" deep and 18" reinforced concrete thick. The blocks interlock like legos.

So, i made a "swag" that if you can stack multiple additional courses of 1600 lbs redi-rock blocks that it will manage the aditional weight of the oven. I will be cantilevered over the front of the blocks by 7" and I will be spanning two of these blocks with the width of the hearth. I also excavated 12" below the top of the back of the blocks the additional depth of the hearth and back filled with washed stone tamped with silt fabric for support and drainage underneath the hearth.

So, I hope that is all going to be good. The wall has been in place for 6'ish years and does not move. It has a fabric protected washed/crushed stone footer with a drain.

Even with all that drainage you may want to consider a vapor barrier between the slab and the ground. Your foundation will be so close to the floor of your oven that you may experience water wicking through the concrete base into the structural floor of your oven and wetting or dampening your floor insulation.

If you are planning some type of stand then a barrier just below the oven structutural layer would work also.

Chip

[david s]

Re: Starting 42" NW Pensylvania

Even with all that drainage you may want to consider a vapor barrier between the slab and the ground. Your foundation will be so close to the floor of your oven that you may experience water wicking through the concrete base into the structural floor of your oven and wetting or dampening your floor insulation.

If you are planning some type of stand then a barrier just below the oven structutural layer would work also.

Chip

There are lots of products available to do this. One that I use is a mix of portland cement and Silasec. Another alternative is an additive you mix into your concrete so the whole supporting slab is waterproof.

[hodgey1]

Re: Starting 42" NW Pensylvania

I have not poured the slab yet. The form is completely finished and i have covered the entire area with plastic. Any thoughts as to weather or not the plastic "visqueen" will be sufficient as a moisture barrier?

[UtahBeehiver]

Re: Starting 42" NW Pensylvania

solid bracing work. Right or wrong I used visqueen for my slab as well. Looking forward to seeing your build.

[hodgey1]

Re: Starting 42" NW Pensylvania

Here is my weekend progress.

[hodgey1]

Re: Starting 42" NW Pensylvania

More pics of progress.

[boylanta]

Re: Starting 42" NW Pensylvania

Looking good.
Nice time to chambfer the top edges of your floor bricks, if you're going to do that (makes for easy sliding of the pizza peel).
I used a dremel w/ an angled grinding stone, which worked pretty well.

[UtahBeehiver]

Re: Starting 42" NW Pensylvania

Hod,

You can save a few bricks by using the cut off on other parts of the floor on the smaller pieces elsewhere on the floor. IE the 5 front bricks could be cut from other parts of the floor saving you 5 whole bricks.

[hodgey1]

Re: Starting 42" NW Pensylvania

Thanks for the tips!

[hodgey1]

Re: Starting 42" NW Pensylvania

More pics of weekend progress.