#1  
Old 01-04-2007, 05:32 PM
Peasant
 
Join Date: Dec 2006
Location: Palmerston North, New Zealand
Posts: 36
Default underfloor mortar - wet or dry?

Should the sand / clay mix under the floor bricks be wet or dry? I understand that the main reason for this mix is to ensure as smooth a surface as possible, but the FB instructions are a bit unclear on this point:

Do not mortar the floor in place, but rather spread a thin layer of sand and fire clay to provide a slip plan between the oven and hearth. That will allow them to expand thermally at different rates.

The underfloor is paste, the texture of a sticky mortar, comprised of 1 part fine sand and 1 part fireclay


Any thoughts?
Reply With Quote
  #2  
Old 01-05-2007, 06:27 AM
Peasant
 
Join Date: Aug 2005
Location: Westerly, R.I. USA
Posts: 36
Default Re: underfloor mortar - wet or dry?

The use of the adjective "paste" is misleading. Laying the mixture dry provides you, amongst other things, the opportunity to level the firebricks. One way of doing this is to gently tap the top of say a piece of "flat" lumber that spans several rows or columns of bricks to eliminate any difference in sapce betweeen the bottom of the wood and the top of the bricks.

A dry mixture also makes it easier to remove any damaged bricks in the future should that be necessary.
__________________
Fred Di Napoli
Reply With Quote
  #3  
Old 01-05-2007, 07:47 AM
pjones's Avatar
Serf
 
Join Date: Nov 2006
Location: Mesa AZ
Posts: 11
Default Re: underfloor mortar - wet or dry?

I am laying down my floor today or tomorrow and I was also thinking it was a paste with water added. I am glad this came up for discussion.
Reply With Quote
  #4  
Old 01-05-2007, 08:35 AM
DrakeRemoray's Avatar
Il Pizzaiolo
 
Join Date: Mar 2006
Location: Littleton, CO
Posts: 1,211
Default Re: underfloor mortar - wet or dry?

Well....I used a paste of fireclay and sand mixed with water. I troweled it with a 1/4" tile setting trowel before laying the bricks on. It worked well for me.

Drake
Reply With Quote
  #5  
Old 01-05-2007, 09:49 AM
Peasant
 
Join Date: Dec 2006
Location: Palmerston North, New Zealand
Posts: 36
Default Re: underfloor mortar - wet or dry?

since writing my query yesterday, I was thinking that perhaps the difference is in the use of the word 'mortar', which is probably what misled me. I now think that perhaps the important thing is not to add any cement to the mix (which is what would make it 'mortar'??). Whether it is wet or dry then becomes a personal choice on what works best to level out the bricks.

boccu
Reply With Quote
  #6  
Old 01-06-2007, 07:42 AM
james's Avatar
Brick Oven Merchant
 
Join Date: Mar 2005
Location: Pebble Beach, CA
Posts: 4,648
Default Re: underfloor mortar - wet or dry?

I think the "personal choice" comment is a good one, as there are a number of methods that will work. Though I think the paste method is the best. For a brick cooking floor, you can use either:

1. A fireclay and sand paste, mixed with water -- you use a knotched trowel to spread it so you can tap the bricks level. The process is like setting tile, but you don't use a cement-based mortar.

2. A dry fireclay and sand mix. You can still set the bricks level that way, through it might be a little more difficult to set the floor.

3. Sand by itself. It you want to keep it simple, or not have to shop for fireclay, sand will do it. Again, it might be a little more difficult to get the cook floor set as level as possible.

I have re-written the cooking floor page of the Pompeii oven plans, which I think are now more clear. Take a look:

http://www.fornobravo.com/pompeii_ov...g_surface.html

Comments are always appreciated.

James
__________________

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
  #7  
Old 01-06-2007, 12:33 PM
Peasant
 
Join Date: Dec 2006
Location: Palmerston North, New Zealand
Posts: 36
Default Re: underfloor mortar - wet or dry?

ta james - much clearer that way in my opinion.
John
Reply With Quote
  #8  
Old 07-25-2007, 06:28 AM
Laborer
 
Join Date: Jul 2007
Location: VA
Posts: 60
Default Re: underfloor mortar - wet or dry?

I used the fireclay, sand paste yesterday and today some of the bricks are still loose. It's also been rained on and I'm concerned my floor is too loose. Nothing has moved but I'm concerned about moving on to building the dome.
Karen
Reply With Quote
  #9  
Old 07-25-2007, 10:36 PM
Unofornaio's Avatar
Journeyman
 
Join Date: Jun 2007
Location: Central, California
Posts: 323
Default Re: underfloor mortar - wet or dry?

Don't be, fire clay will stay soft for a very, very long time its final set (hardening) is with heat, depending on weather and thickness it can stay soft for days. This mixture for the floor is really only there to enable setting the bricks level. I would purchase a tarp, your gonna need to keep the rest of the build from this point on out of the rain.

Good luck
Reply With Quote
  #10  
Old 07-26-2007, 02:40 AM
Laborer
 
Join Date: Jul 2007
Location: VA
Posts: 60
Default Re: underfloor mortar - wet or dry?

I'll do that. I ended up taking the whole floor up anyway because I looked at my bag of "fireclay" yesterday and saw they store delivered me one bag of ground clay, not fireclay. Wouldn't you know, that's the one I chose to open and use. I cleaned it all up and used the right stuff and I got it layed tighter and smoother anyway. I feel better. Today I begin the dome. I'm excited.
Karen
Reply With Quote
Reply

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



All times are GMT -7. The time now is 03:30 AM.

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