#1  
Old 09-01-2009, 08:59 PM
kebwi's Avatar
Il Pizzaiolo
 
Join Date: Aug 2009
Location: Seattle, WA, USA
Posts: 1,010
Default Alternatives to concrete hearth

Bear in mind that I am building a 36" oven, pretty small. So, when considering my ideas below, factor in the weight of a 36" oven and associated infrastructure, not 42".

In an effort to minimize mixing and pouring concrete, I'm wondering if there are other ways to create the support slab for the hearth.

Idea 1:
Get one of those killer plates of steel that are placed on the street during construction. That would work, right? But is it feasible? Meaning, can individuals purchase that stuff in the first place, can we get it cut (or in a size that we can design around), is it an affordable option, and is it actually structurally sound for the purpose of support these ovens?

Idea 2:
Lay extra rebar but no concrete, maybe every 6". Wire it up tight so it won't shift. Lay a heavy piece of plywood across the top to form a flat base for the insulation layer. Would I need some plastic between the insulation and the plywood (does wood not like to have concrete laid directly on it? does it rot or something like that?) Same questions as above. Is this affordable relative to pouring concrete and is it structurally sound?

Idea 3:
Lay a bed of 4x4s or some other kind of thick timber across the cinder blocks. If one could groove them, one could even align rebar along the length of some of the beams. Same questions as above. Is this affordable relative to pouring concrete and is it structurally sound?

Problem with concrete is, frankly, I don't think I have "those kinds of friends" here, not yet anyway, so I'm going to doing most of this job truly on my own with *maybe* a little help from my wife.

As to the foundation, I haven't decided yet, I might have it done for me or use one of those small-jobs concrete deliverers.

Thanks, worried...unsure how to proceed.
Reply With Quote
  #2  
Old 09-01-2009, 09:23 PM
Lars's Avatar
Journeyman
 
Join Date: Oct 2008
Location: Omaha
Posts: 255
Default Re: Alternatives to concrete hearth

Hey Worried!

My son and I poured the hearth base slab with an 'od-job' bucket. Basically, you pour in an 80lb. bag after a gallon of water. Roll it around a while, then pour it in the form.

You and your wife can do it! Especially in Seattle! Not so hot! There are many tricks to save you back and increase your capacity. You will need about 16 bags, but be sure to calculate and have plenty on hand. You can use up any extra in the holes of the block wall! ( and hey, concrete is cheap)

So, here's the tricks! Get your bags all on a ledge somewhere ( out the back of an SUV will work) put down the bucket, pour in a gallon of water, then slide the bag over across the top of the bucket. Get a cheap small wood saw. Cut the paper bag at the bottom and let it all go in the bucket.

Put on the top and roll it to the hod. Best if you can park uphill from your site. You will not believe how much concrete you can pour this way!

Lars.
__________________
This may not be my last wood oven...
Reply With Quote
  #3  
Old 09-01-2009, 09:31 PM
kebwi's Avatar
Il Pizzaiolo
 
Join Date: Aug 2009
Location: Seattle, WA, USA
Posts: 1,010
Default Re: Alternatives to concrete hearth

Ha! That's hilarious. I love it. God help me if the lid comes off and it dumps on the lawn. I'll think about it.
Reply With Quote
  #4  
Old 09-01-2009, 09:39 PM
Il Pizzaiolo
 
Join Date: Jan 2007
Location: Tampa, FL
Posts: 1,446
Default Re: Alternatives to concrete hearth

A heavy gauge steel framework could work along with a heavy steel plate or heavy gauge corrugated steel steel sheet. Exactly how heavy......not an engineer. We have had a few builders go this route, hopefully one of them will step in and give some advice.

ANY kind of a wood substructure is not a good idea. 1) wood rots & 2) would expands and contracts (more than you think) which can/will cause movement of your oven (not good for a mortared brick oven = cracks)

RT
Reply With Quote
  #5  
Old 09-01-2009, 09:41 PM
Les's Avatar
Les Les is offline
Il Pizzaiolo
 
Join Date: Sep 2005
Location: Carson City, NV
Posts: 2,857
Default Re: Alternatives to concrete hearth

Keb, all bad ideas except the plate steel, but that is crazy expensive. Just follow the plans - it really is not that hard to pour your hearth. Do you have a United Rental in the area? - they will sell you a yard at a time - thats the route I went. I bought a yard , poured the hearth and filled every other core at once, well worth the price (my back thanked me)

Les...
__________________
Check out my pictures here:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


If at first you don't succeed... Skydiving isn't for you.
Reply With Quote
  #6  
Old 09-01-2009, 09:47 PM
kebwi's Avatar
Il Pizzaiolo
 
Join Date: Aug 2009
Location: Seattle, WA, USA
Posts: 1,010
Default Re: Alternatives to concrete hearth

Thanks for the responses. I'm just brainstorming. Seems inevitable I would strike several misses in the process.

Cheers!
Reply With Quote
  #7  
Old 09-01-2009, 10:04 PM
Journeyman
 
Join Date: Jun 2009
Location: minnesota, usa
Posts: 472
Default Re: Alternatives to concrete hearth

it won't be fun, but pouring a foundation or hearth slab or both, is defiinitely do-able with two people assuming one of you can lift 60 or 80 lbs repeatedly. Even moreso if you have small batch ready-mix or on-site mix places there. Then basically all you have to do is screed and trowel and that's an easy one person job.
Using bagged mix, we did my foundation slab with two people. Cool weather=no problem. We had a helper for the hearth slab, but it was like 95 degrees and blaring sun that day so time was a big factor. We used a gas powered mixer from the rental place both times, but I've mixed bags and bags using an OddJob for other projects. They're great. Another idea would be to hire someone from your local day laborer office...every city has at least a few of those places.

never use wood to hold up concrete, and definitely don't use it to hold up something relatively fragile like bricks and mortar.

using a steel framework stand (FB sells one) would get you around having to pour one of the slabs and lay block, but really the only way you'll have a support for the masonry that is stable enough is if it's concrete.
Reply With Quote
  #8  
Old 09-02-2009, 05:40 PM
Neil2's Avatar
Il Pizzaiolo
 
Join Date: Oct 2006
Location: Vancouver Island
Posts: 1,374
Default Re: Alternatives to concrete hearth

"Keb, all bad ideas except the plate steel, but that is crazy expensive."

I agree with les.

Pouring conrete is not difficult. If you want to gain a little experience start with some sidewalk or stepping stones or something else on your yard.
Reply With Quote
  #9  
Old 09-02-2009, 08:17 PM
dmun's Avatar
Moderator
 
Join Date: Jul 2005
Location: New Jersey USA
Posts: 4,216
Default Re: Alternatives to concrete hearth

If you go with steel plate, the place to go is a steel fabricator. There's undoubtedly one near you. Be advised, it will cost to buy, and also cost to rig in. It's still a lot of weight, so you would still need proper foundations, meaning you still have to deal with concrete anyway.

And as others have said, no wood under the oven, no way.
__________________
My geodesic oven project:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #10  
Old 09-02-2009, 09:58 PM
Mitchamus's Avatar
Journeyman
 
Join Date: Aug 2008
Location: Sydney & Snowy Mountains
Posts: 385
Default Re: Alternatives to concrete hearth

you'd also need a crane to lift it in place
Reply With Quote
Reply

Tags
concrete hearth

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Concrete for the hearth slab. I burnt my fingers Getting Started 6 08-23-2009 09:46 AM
refractory concrete hearth? David Reekie Newbie Forum 0 03-19-2009 04:24 PM
concrete blocks on top of vermiculite/concrete hearth project1 Getting Started 10 07-31-2008 06:19 AM
Insulation below or above concrete base for Oven Hearth tdibratt Pompeii Oven Construction 5 07-07-2008 05:03 AM
Poured hearth, questions about concrete and insulation... Frances Getting Started 9 09-14-2007 09:59 PM


All times are GMT -7. The time now is 06:20 PM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
© 2006/10 Forno Bravo, LLC