39/42” Corner Building in Brisbane

[Delta]

So maybe give them a soak and leave to dry off?

[MarkJerling]

Back on the job after a weekend of storms, need to get action happening.
I am awaiting getting my arch bricks cut but can at least get some construction happening.
So I have assembled a gazebo to protect from the weather which will unfortunately make it a bit hot during the day.
I found a box of unused ceramic tile from a bathroom upgrade so have stuck those to the hearth and drilled 12mm holes through the hearth for water drainage.
One layer of 50mm Cascil sheet for under oven insulation, I went for maximum usage of these sheets so my floor runs to the extent of the insulation beneath.
Assembled the floor in a herringbone pattern making sure I didn't have any of those small of cuts at the opening of the oven.
As I am constructing the dome header bricks directly on the oven floor, I did not worry about having a complete circular base, there are some small fillers missing that I am just going to "Mud" over with some homebrew.
I have mortored in the floor with a homebrew using the 3:1:1:1 ratio which went well but I didn't think that it went off rapidly at all. Actually even though I did wet the brick edges down slightly, I didn't think it stuck really well? I did check this morning and appears to be hard and cemented in place.
I am just going to keep building and see what happens, I do not have any plans once the dome is complete, I am hoping to attack the landing and chimney as I come to them, from my reading, a lot of people change their minds as they come to stage so it should be ok for me as well?

That's looking good!

[Gulf]

.....I did brush them with a wet brush but think that it was not enough.......So maybe give them a soak and leave to dry off?....

Another thing that can cause mortar bonding problems is dust. All loose material should be removed from the brick. Any brick that I cut dry is cleaned vigorously with a dry brush to remove all dust. Any brick that I cut on the wet saw is washed before setting aside to dry for a while before laying. Wet dust can be a little more difficult to remove. I like clean flowing water to remove that. Soaking is something that I don't do. It may have a purpose for someone dry cutting a lot of brick with a saw. But, soaking a brick just to lay it with mortar will has no purpose imo. As david s said, a brick must be dry for the mortar to bond. On days that I think that the brick will pull the water out of the mortar too fast, I will use a spritz bottle ( an old windex bottle works good) to add just a little moisture. A quick spritz could also be used to test a brick that has been soaked. If the water droplets don't immediately soak in to the brick, it is too wet to lay.

[Delta]

Thanks Gulf.
I have cleaned off the old mortar and scored the brick edges to give contact surface to see if this helps.
Have used a spray bottle to moisten surfaces to see if this helps.
This time when applying the mortar, it started to go of quite quickly?
Maybe this was the brick pulling the moisture out of the mortar?
Anyway checked this morning and it look better however there are some vertical cracks between bricks?
Is this normal and do I just ignore these?
I think they appear more where the brick is only a small piece and may be a bit more unstable than a whole brick?

Anyway, am pushing ahead and have laid out the header course which have been cut to suit and fits tightly together.
Does everyone butter the mortar between bricks in this case or just mortar the outer edge?
Status photos attached.
Cheers

[JRPizza]

If you look at my build I also had trouble with adhesion on the first course. I did like you and refined my process - brick prep, mortar consistency, and application. Also, once you start to add courses with mortar on all sides of the bricks it will all stick together fine.

[Delta]

Thanks JR,
Yes went back and had a look at your build, again, and decided to just push on.
My floor bricks seem slightly uneven so will bring the edges off to avoid lips.
I thinking I have been suffering from “over thinking it”, it’s just bloody brick work after all, no need for millimeter precision.
So went ahead and mortared down the first course and ran out of blend to go any further today.
I have just been making the 3:1:1:1 blend up in bulk and keeping it in a bucket so I can just make small batches.
i have been soaking the bricks in a bucket of water and surprised at the amount of effervescence when they are soaking, even more surprised at how quickly the mortar goes off once it is put on the brick.
Is there anyway to slow this down?
I have been make the blend very creamy, almost like whipped cream rather than firm like peanut butter.
Anyway will if I can lay the second course tomorrow and start trimming the bricks for third course.
Cheers

[Delta]

Put the second course down yesterday.
I don’t have the arch bricks cut so will just build up to arch and cut them in as I go up, does this sound like a sensible idea?
Just now need to work out how to mark out the bevel(?) for the third course as the inverted V is now showing.
I was wondering if I can use my laser level to mark the bevel?
Any thoughts.
Cheers

[JRPizza]

To get rid of the inverted Vee I used a sliding T bevel, which you can pick up here in the States relatively cheap. If you don't have one they are a nice addition to the tool box as I have used mine to transfer/copy angles many times doing home repairs since I built my oven. For brick beveling I would just lay the handle of the bevel along the top of a brick and then eyeball the blade upward perpendicular to the plane of the base of the oven. Then I'd tighten the knob and take the bevel over to my saw to transfer the angle. I tried using the spreadsheet and a digital caliper to set my saw but found just transferring the angle to be much faster and more reliable.

[Delta]

Thanks JR. So really if I set the sliding bevel on top of my brick and use the laser to shoot a line from the bottom corner of my brick it should achieve the same thing. This angle should remain true for all bricks on that course?
Without a brick saw I can see that this will become messy.
Also on another note, it would appear that maybe my posts should be in another part of the Forum maybe?

[JRPizza]

I didn't realize you were working without a saw - that will certainly make cutting the bevels more difficult. Yes, for all same width bricks the bevel should be constant along a row. Without a saw you could always use an angle grinder with masonry disk and just rebate the inner edge with the bevel - no need to take the angle all the way to the outside end. Some builders have done that to reduce the amount of cutting necessary and still close up the Vees

[Delta]

I had a saw in the initial phase but had to return it, I do have a grinder and masonry blade.
I am now looking to get a 2nd hand saw.
When cutting the bevel I didn’t think that the cut would initially go all the way to the back, more like just trimming off the top front corners and progressively trimming more and more.
As a rule of thumb, how many layers up do you go before changing from half bricks to third bricks?
Cheers

[JRPizza]

Not sure about when to switch to thirds. I went a different way - in an attempt to keep all my vertical joints centered on a brick below, I make the bottom width of the bricks in a row the same width as the upper ID face of the brick below it (let me know if I messed up the explanation). This led to my bricks becoming smaller and smaller as I progressed upward but kept the joints neat. I probably went through more bricks that way but a big part of building an oven is figuring out what makes sense to you and is within your skill set and sticking with it. With my saw set-up I cut an edge with just enough taper, then flipped the brick over to cut to width with the proper taper on the other side. I repeated that for the remminant and was left with an increasingly larger leftover as the bricks got smaller. Somewhere in the build I got to where I was getting 3 bricks out of one but would have to stick my head into the oven with a ruler to figure out when. I even got to the point where I could have used 1/4 bricks but switched back to 1/2 at that point which kept the joint pattern correct. Sorry about the long winded reply.

[Delta]

No that makes sense to me. I had read somewhere, maybe your build about make the base of the brick above the same width as the top of the brick below. Made sense at the time but was not aware of it maybe becoming a consumption issue.
As our local brick manufacturer here in Brisbane no longer exists, I am having problems locating more brick as I think I will run short?
I have not even considered my landing and chimney yet, does the chimney need to be constructed of fire bricks?
Cheers

[cobblerdave]

G’day
Its great to get a neat result but sometimes you’ve got to work with what you have. I built to a ply form with an angle grinder and a brick bulster. The inverted v aren’t dreaded the pic is my oven yesterday still standing. I had a crack at cementing the gapes but decieded I didn’t really like small spaces and just left it as it was. It’s been 10 years now. Still cooks and definitly still standing.
Remember it’s a dome and gravity holds everything together the mortars just there to keep the brick orientation to each other and there not the glue that keeps the dome upright.
regards Dave

[Delta]

Thanks Dave,
Going to pick up a new Wet Saw today, if I keep it clean, I should get a decent price for resale.
I can't afford to waste bricks as I can't seem to find any locally at the moment.
Do I need to use oven bricks on the chimney?
Cheers