web analytics
Adhoc 36" Oven in Lake District, UK - Forno Bravo Forum: The Wood-Fired Oven Community

Announcement

Collapse
No announcement yet.

Adhoc 36" Oven in Lake District, UK

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #61
    But then, Tues morning this week - woke to Disaster? ?

    My concrete hearth slab revealed a full length CRACK! Side to side, centre of slab, down full thickness.

    Some info - It IS all reinforced with wire mesh (see pics) there are no cracks in brickwork either on slate base walls or inside oven. Exterior of oven - no cracks. Underneath the hearth slab, whilst it gets pretty warm - crack does not show on underside. On top of concrete slab, I used some cement/mortar to place and level ONE calsil board (not two...wish I'd done so!) Then fireclay on top, with oven floor bricks on them.
    Concrete is 4 inches thick at max but as low as 3.25 inch thick (where the crack is on one side)

    The crack is hairline and appears to have closed up a bit more now. The concrete slab sat for weeks before any fires were lit. Boards and supports were under for a LONG while too.All but one of the support legs came out with little or no effort.

    Should I be concerned?

    Comment


    • #62
      Could anyone advise on my last post please? Should I be concerned at all? Cheers

      Comment


      • #63
        Click image for larger version  Name:	image_22364.jpg Views:	2 Size:	132.1 KB ID:	412387Click image for larger version  Name:	image_22604.jpg Views:	2 Size:	118.8 KB ID:	412388

        Micky,

        I would not be to concerned about the cracks it is only hairline you have put enough mesh in the concrete to hold it all together most concrete will crack at some stage thats why they put expansion joints in concrete slabs as I said the mesh is there to hold it all together
        Micky unfortunately people get the use of mesh and reinforcement wrong, mesh is for use when laying concrete on the ground and rebar is used when pouring a suspended slab most would use 1/2 inch rebar for a suspended slab and perhaps F7 mesh for concrete driveways etc

        Cheers Doug
        Last edited by Karangi Dude; 04-18-2019, 02:42 AM.
        https://community.fornobravo.com/for...-s-48inch-oven

        Comment


        • #64
          Originally posted by Karangi Dude View Post
          {"alt":"Click image for larger version Name:\timage_22364.jpg Views:\t2 Size:\t132.1 KB ID:\t412387","data-align":"none","data-attachmentid":"412387","data-size":"medium"}{"alt":"Click image for larger version Name:\timage_22604.jpg Views:\t2 Size:\t118.8 KB ID:\t412388","data-align":"none","data-attachmentid":"412388","data-size":"medium"}

          Micky,

          I would not be to concerned about the cracks it is only hairline you have put enough mesh in the concrete to hold it all together most concrete will crack at some stage thats why they put expansion joints in concrete slabs as I said the mesh is there to hold it all together
          Micky unfortunately people get the use of mesh and reinforcement wrong, mesh is for use when laying concrete on the ground and rebar is used when pouring a suspended slab most would use 1/2 inch rebar for a suspended slab and perhaps F7 mesh for concrete driveways etc

          Cheers Doug
          Thanks for the response Doug. Nothing else appears affected. Looking at my pre-concrete pour pic, there is actually doubled up metal mesh around the area of crack. Just caused a minor panic. Don't see anyone else on here with similar issues!

          Comment


          • #65
            Remember the old adage "There are two types of concrete pours...those that have cracked and those that will crack." As Doug said, the interior reinforcing (rebar/wire mesh) is the primary factor in the lateral/flex strength for any concrete slab...concrete is providing mostly compression strength. As to others with similar problems...there have been many folks that are concerned with minor cracks in their stand's concrete top platforms. Most folks have done some sort of external enhancement such as tile or stone on their stands and hearth, so you just don't see/notice that fairly common minor cracking.

            Relax and have a tasty, adult beverage to celebrate your excellent build!
            Mike Stansbury - The Traveling Loafer
            Roseburg, Oregon

            FB Forum: The Dragonfly Den build thread
            Available only if you're logged in = FB Photo Albums-Select media tab on profile
            Blog: http://thetravelingloafer.blogspot.com/

            Comment


            • #66
              Micky,

              Like the others, I don't think you have anything to worry about. However, you might want to reinforce the hearth with a center support. I built mine in an "H" pattern too provide additional support in the center. If your stand is rectangular you could build a block support/center stand in the middle of your slab?

              Cory

              Comment


              • #67
                Thanks for the feedback SableSprings and cbailey Problem I was worried about was - Ive never HEARD that old adage about concrete pours! Ive heard many a time about "There are ovens with cracks and those who lie about the cracks" But seen nothing on the concrete slab as such. Im not worrying about it. The pizzas are coming out really good and I got a fantastic trip advisor review the other day.
                Vermiculite is looking very light in colour now and once its almost entirely that way, I think I'll be ready for my cement and slate rendering. What mix do I use of sand/cement and should I add anything in there to add elasticity (for cracking) or weatherproof related stuff?
                And thanks cory - I do have a central pillar of breezeblocks underneath already. I'd thought that far ahead. Your's looks Nukeproof in comparison mind! Your build is coming along great

                Comment

                Working...
                X