Masory fire boxes

Discussion in 'Smoke Houses' started by archeryrob, Oct 27, 2015.

  1. I am building a smokehouse very similar the Atcnick's Cedar smoke house posted a few threads down. The big question I have for anyone that built one is the roof of the fire box. How is everyone supporting the flat roofs on these? The most difficult part and there isn't any details on construction.

    I don't want to drop a bunch of 2" angle iron all through it for each course. I though about building  a curved roof like they did on bridges, but I'n not a good enough mason for that.

    The latest idea is the framer the 4 sides and make a frame for the top, lay down fire bricks with some gaps and make a 1/2 rebar cross hatch over it. Then pour 4 inches of high stregth concrete. I am assuming I would likely now brick the front and pour over the sides and back as its likely to weight 150# or more once poured and be a bit difficult to set on my own. :)

    I watched the video for Tim Farmer and they use a standard block post cap with is kind of light concrete. Once looking at one it wasn't my first choice.

    How did you guys that did it make the roof?
    Last edited: Oct 27, 2015
  2. Man, don't everyone jump out at once with ideas. [​IMG]

    Here is a picture of the fire box. The inside bricks are firebricks and the blue are 481 standard bricks I have as leftovers from house repair and the top is 8" square flue pipe going to the smoke house. I'll set the floor with fire brick and then set the 481's around the back and side. Then set the fire bricks on the sides and finish the front.

    For the roof, I'm figuring on a  2" angle lentil over the door and the flue pipe. Then I'll probably run 1 1/4" angle iron down the center in tow pieces and weld to them to form a T. This will probably be welded to the 2 - 2" angle irons to form the lentil and roof support. I'll them set the roof firebricks like the bottoms and rest them on the angle in the center and the tops of the side fire bricks. Then mortar and cap over the set fire bricks with 481 standard bricks. I might set the entire firebox in high temp mortar even though I could probably use N on the outside layer.

    Comments? I really want it strong as it would not surprise me to find my daughter standing, or sitting, on it when its not in use.

  3. smokerjim

    smokerjim Meat Mopper

    years back i built a block smoker for my brother,luckily i have a friend that works in a metal shop,he made me a top out of 1/4 inch steal reinforced with angle iron in an x shape to keep it from warping,i mortared that to top of fire box,works great. 
  4. ukenout

    ukenout Fire Starter

    I'm curious tomboy your doing the firebox as well, ill be starting mine this weekend.

    I thought about getting a bigger section on 13x13 clay flue pipe and lining the walls with firebrick and then connect to my 8x8 clay pipe, add a 8inch door. Just don't know if this will be big enough or if the clay flue liner can support the heat but I dont see why it wouldn't.
  5. The clay pipe they sell for chimneys will support the heat. I was figuring I should elevate my pipe more than 3.5" so I will be changing to 3 sections of 6" steel single wall stove pipe as I did not want to deal with raising the clay flue and possible bricking all around it to protect it. It seems kind of fagile and I would think you'd want to always brick around it.

    I just bought some S type motor for around the fire box and N motor for the concrete blocks. That fire motor was $50 a bag! The guy at the brick store said the masons don't like using it but have to for code on chimneys. He said they used S type motor for years and masons don;t like the fire motor as they do think its as strong. I'm going to only butter the bottom fire bricks to level them and butter the sides the same for adhesion only. The top will rest on the sides and the middle lintel I make and maybe just a bitters between to seal it. Standard brick around the outside and over brick over the top to cover the fire brick from the weather and daughters, Long story.

    Post some pics on your progress as I was going to strat this weekend but other issues are slowing me down until next weekend maybe.

    I poured the concrete pads already.

    Last edited: Oct 31, 2015
  6. ukenout

    ukenout Fire Starter

    Well I still am sourcing all my firebrick and stuff, but did get the cedar house done today.

    Started a small smoke can just to see how it vents.

  7. What wood did you use? Those look like fence slats. What is your roof?

    I was thinking about using standard wood for the box and making a ceiling on that. Then using pressure treat for the rafters and a tin roof for ease of maintenance. Then I don't have to worry about sealing or fixing the roof or water on any exposed roof trusses. I would just do a side wall vent.
    Last edited: Oct 31, 2015
  8. ukenout

    ukenout Fire Starter

    Ya they are WRC fence slats, its hard to find red cedar around here but this is what I was able to find at a reasonable price. I didn't use any pressure treated stuff in the smoke house as other members said it wasn't good (chemicals). I used white board. I used the slats to even make the roof over the smoke house but then used the red metal roof over it. I put a a side vent piece going out the back so my neighbor can smell the awesomeness.

    I got a bag of fire clay on Friday, I have to figure out how to mix it with motor now.
  9. bauchjw

    bauchjw Master of the Pit

    I was thinking you could just make a concrete cap and put it on top. Kind of hard to explain. You tube or Google DIY concrete counters or tabletops and it may explain what I mean. Once you pour the small slab you can attach the fire bricks underneath and put it on top as a cap. These types of tables are built to carry a load. Good luck!

  10. bauchjw

    bauchjw Master of the Pit

    Woops, final image after it comes out of frame/ mould. Then you have a sold slab to move around. Fire bricks on interior would ensure your daughter doesn't push it off.
  11. I forgot to update this for anyone else researching this. I built a frame and used 3/8" rebar and tied it with wire. Used a couple chunks of concrete to act as stand offs to raise the re-bar close to the middle. Used a support board as the ceiling support and propped it up with 2x4's I could knock out later on. I could not pull the plywood out later on, I lowered a little and a real pain in the butt to try to get in there and cut it up. I made a small fire and burned it slowly until it fell apart.

    The support 2x4's

    Last edited: Jun 18, 2016
    bauchjw likes this.
  12. Also, an FYI, I used plastic anchors to hold the fire box door with SS screws. The plastic anchors held when making bologna when burning for a couple of hours. This fire was started at 5:30 am and hot enough to start smoking at 7am and 220° around 5pm when the door fell off on me. [​IMG]

    A little research shows plastic melts as 338° and lead melts at 621° so I need to find some 1/4" lead anchors. I haven't used them since the '80's
  13. pito82

    pito82 Newbie

    What kind of pipe can I use for my barrel which is my fire box connecting to my smoker.
  14. bauchjw

    bauchjw Master of the Pit

    Points for a really cool build!
  15. Pito, for your barrel I would assume you'd use single wall 6" the the kits uses for the Vogelzang or USSC kits have. I am not sure they make a barrel adapter for 4" pipe
  16. pito82

    pito82 Newbie

    Thanks a million
  17. I followed some of the guys advice in other threads. When starting this up I get to 120° right away and that is too warm for cold smoking. Once that brink is hot later in the say I can get 220-230 easy. I installed a heat bypass with dampers and took this pic before painting them so you can see it. 

    I cut the bottom 1/3 off the Tee and slipped it over the pipe and then cut a hole in the exhaust pipe. Added 14" of pipe on top with a elbow and made a rain cap by cutting a connector and adding a flap to keep rain from blowing in the opening.

    I am going to be killing deer at my buddies and he is pushing for me to start making sugar cured deer hams.

  18. Also, a things I learned is that I only ran the fire bricks up two courses as the coals are not that high. That brick gets very hot later on and I have cracking in my joints above the fire brick. I would suggest running it up the full height. Mine is not going to fall apart it just opens cracks when hot and they settle back down when cool. 

    I might rebuilding it next year, if no other project is taking the stage. I will take the top two brick layers off and make a domed ceiling from fire brick. Might fill in the voids with a S mortar with aggregate like cement. Make an opening in the top and keep building it higher and build an oven on top the fire box. I can use the over as the fire by pass when smoking. Maybe even cook a chicken or a wood fired pizza in the oven, but that is the possible future plan. 
  19. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    If need be to lower the smoker temp, make the bypass stack taller...  then it will suck more heat out of the firebox...  getting the balance will take time...  I'm positive you will be happy with the controllability of the heat and smoke...

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