Basic questions on building base / installing Toscana 90

[giambra]

Hello,
I am considering a purchase of the Toscana90, have a few basic questions about building the base and moving the oven on the base.

Once I pour the foundation and dry stack the cinder blocks, I will fill every
other hole with rebar / concrete. This means every other core / hole will still
be empty when I pour the structural hearth. From the Casa 90 instructions, it looks like I can use the empty concrete bags to keep the non-filled cores from creating a problem. Questions:

1. For the cores that span the angle iron / arch in the base, I don't think concrete bags will do. Do I need to build a form underneath those openings? Is there another trick?

2. If I do the Toscana 90 (so only a structural hearth, no insulating layer), is
3 1/2 inches thick enough?

3. I see from the instructions for the Casa 90 that cement backer board is layed down. It wasn't clear to me exactly what this is for. Does this backer board cover the entire bottom layer of the structural hearth? Is this on top of the plywood that is the bottom of the form? If so, does it go all the way to the edge (to completely cover the bottom of the structural hearth)?

4. I have found a crane company that will (reasonably) bring in a boom truck, load the oven move to the stand and place the oven. It does not look like there is a lift point on the oven. Will the company use straps? If so, how are the straps removed once the oven is in place?

Thank you,
Tim
Raleigh, NC

[christo]

Re: Basic questions on building base / installing Toscana 90

First - congrats on your decision to join us WFO pizza burners!!!

I think I can answer your questions... I'm not familar with the Toscano 90 - other than wanting one for myself....

1. For the cores that span the angle iron / arch in the base, I don't think concrete bags will do. Do I need to build a form underneath those openings? Is there another trick?

Concrete bags will work fine - so will bubble wrap I went another route and used duct tape and cardboard under the bottom so I could get a fully filled core right down to the angle iron on every block on the span- As an alternative there are builders out there that spanned the opening with the hearth pour and bypass the bridge of blocks over angle irons all together.

2. If I do the Toscana 90 (so only a structural hearth, no insulating layer), is 3 1/2 inches thick enough?

It should be fine - remember the oven's weight is spread over a wide surface area. I went with 4 inches on my oven. sounds like the toscano 90 is already strucurally sound. From what I read - there are optional legs - I might go with those and build up walls around the oven and omit the hearth pour.

3. I see from the instructions for the Casa 90 that cement backer board is layed down. It wasn't clear to me exactly what this is for. Does this backer board cover the entire bottom layer of the structural hearth? Is this on top of the plywood that is the bottom of the form? If so, does it go all the way to the edge (to completely cover the bottom of the structural hearth)?

I used concrete backer board instead of plywood form for the bottom of my hearth - it covered it completely and I left it in place after the pour. I cut the board so it was 2 inches larger than the opening and braced it with 2x4 - across with vertical 2x4's for support. it held the weight of the concrete just fine - use rebar just like the plans say - add a few extra to span the opening if you omit the block and angle iron.

4. I have found a crane company that will (reasonably) bring in a boom truck, load the oven move to the stand and place the oven. It does not look like there is a lift point on the oven. Will the company use straps? If so, how are the straps removed once the oven is in place?[

I think the crane is a good idea. I saw two different DIY shows folks using a bobcat with forks and there was not good control on laying it in place. Looked like it slammed down.... I would put some shims just a bit thicker than the straps under the oven when you place it - and remove them after you remove the straps. I would suggest making my shims from - a four foot long 2x4 with a long bevel. That way after you remove teh straps - you can smiply move the 2x4 back and forth as you pull it out - the bevel should acutally push it out. I bet your crane guys will have this all thought out for you already!!!! They tend to protect their straps.....

Good luck and good cooking!!

Christo