To taper or not to taper?

[cholme]

Hello, I am in a waiting period right now as my insulating layer cures for the next week. I am building a 32in ID oven with a 16in dome height.

I would love to hear pros and cons to tapering and not tapering... it seems like a lot of work, but if it is worth it then I will do it.

Thanks in advance.

Chris

[lwood]

Re: To taper or not to taper?

Tapering what?

[cholme]

Re: To taper or not to taper?

Sorry... I mean tapering each brick in the dome to fit the circumference and the arch - or just filling the gaps with mortar.

Make sense?

[gt40]

Re: To taper or not to taper?

Sorry... I mean tapering each brick in the dome to fit the circumference and the arch - or just filling the gaps with mortar.

Make sense?

I would try to cut the bricks as close as you can. You will soon figure out if you are up to cutting them all that way :P

[GianniFocaccia]

Re: To taper or not to taper?

Draw out a profile of your dome on a piece of paper and simulate the placement of untapered 2 1/2" bricks. If the resulting outside gap mortar requirements are within reason to you (and your pocketbook) then you're good to go. Don't forget to factor in your inside mortar gaps. The larger your outside gaps the more propensity your mortar has to shrink and crack. If you taper your bricks you decrease the joint size, reduce the mortar requirement and increase the amount of work required.

[John K]

Re: To taper or not to taper?

Hi Chris

I just tapered the inside bricks to ensure an edge to edge finish and did not worry about the outside. Iv'e been using the oven for over a year with not 1 crack so the closer the edge the better by the looks of things. At the end of the day it comes down to how much patients you have and what finish you are after

cheers John

[cholme]

Re: To taper or not to taper?

Thanks for the input so far. I actually have a followup to my own question. If I were to taper all the bricks so that they match the curve or the arch etc. wouldn't there actually be a larger mortar line inside the oven? With no taper, the bricks will actually touch each other, with the exception of a gap on the sides, will they not? Or am I over-thinking this?

[Faith In Virginia]

Re: To taper or not to taper?

This is a picture of my bricks this is one of the higher rings but it shows the type of cut that worked for me. I also included a picture of my interior so you can make a choice in the amount of effort you want in your oven. Hope this helps.
Faith

[lwood]

Re: To taper or not to taper?

Hi Faith,
Are those tapered bricks a lot more expensive? After seeing yours, I would seriously consider using tapered bricks. Your oven looks perfect, joints are nice and tight.

One thing about tapered bricks is; they will never fall out of position.

[lwood]

Re: To taper or not to taper?

Or did you cut all those bricks your-self? I took another look at your pic and you cant buy bricks like that.

[md_massimino]

Re: To taper or not to taper?

I don't know, seems a bit obsessive to me. According to all the threads I've read, even the ovens that have cracked mortar seem to be completely operational and in no danger of falling in. For me the oven is a means to an end, I'd rather obsess over dough and sauce and cooking techniques.

[mrchipster]

Re: To taper or not to taper?

Attached are 2 images of model I am building in Google sketch-up. In the model I have tapered the first 3 chains and then chain 4 and up are all made with the brick tapered for the 3rd chain. as you can see the gaps get significantly wider both inside and outside as you go up and the angle between the bricks side to side becomes much more pie shaped.

The higher rings should use much narrower bricks as you go up to help with the top and bottom gaps that develop because of the smaller chord tangent points due to the smaller radius. Some of the bricks are not ideally placed and done freehand but the concept is clear.

First image is outside the dome and second is inside view.

Chip

[Cheesehead]

Re: To taper or not to taper?

I tapered mine. I cut them on a table saw, about a 5 degree angle horizontally & vertically (inside to outside). As I got to the top, I also angled each brick so the face was trapezoidal (portion closer to the top of the oven smaller than the dimension on the bottom). With the table saw, this was easy to do.

Each full brick took five cuts to make two tapered trapezoidal half bricks. The cutting went fast once I got the hang of it and saved a lot of time mortaring. I won't say I got perfect fits, but they went together pretty well.

[Faith In Virginia]

Re: To taper or not to taper?

lwood. I cut those bricks myself. So they started out as a standard brick.

If you noticed the interior section of the brick is narrower and the exterior wider. So in a sense each ring of brick is like an arch and every brick a keystone. So even without mortar the bricks can't move. Every ring is slightly different so you would need to make adjustments as you go up.

Thanks Faith

[lwood]

Re: To taper or not to taper?

That's amazing Faith, wish I had the patience to do that. Maybe on oven #2. Is it necessary, maybe not, but it sure is a work of art when completed.