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Re: Dome spreadsheet calculator
H12rpo -
The spreadsheet is giving you the right numbers -
- The soldier course and the first course have the same radius (always measured at the bottom of the course) so they require the same number of bricks.
- It's 29 bricks instead of 24 because it assumes you are tapering your bricks. Look at column "P" - the inner width is 3.53". that's how you get to 29 bricks. I probably wasn't clear about this in the assumptions
- To the question about 29.2 vs. 29 1/2 bricks - the way I set it up, it gives you the bricks needed to the 10th of a brick. So realistically, if it says you need 29.2 bricks, you might use 29 bricks with a little thicker mortar gap. Or, you could (quite painfully) cut every brick a bit narrower to use an even number.
- Your comment about using half bricks - yes, but with tapering. The spreadsheet assumes the bricks are all standard width (usually 4.5 inches) at the back unless the builder enters a narrower width in column "R". I built in the ability to change this because I at some point almost every builder starts cutting the bricks into thirds or even smaller in order to make them easier to work with.
In the end, It's really up to the builder - but your questions are good ones to help understand how to interpret the calculations. I set the spreadsheet up to make the taper calculations really easy to do and very accurate. The brick counts were a by-product of that. But if you want to build an oven without tapering the bricks - then I'd look at the calculated radius for each course and use the math you propose to get to the brick count. It shoudl be quite easy for you to add a column to your own version of the spreadsheet that will give you this.
Does that all make sense?
H12rpo -
The spreadsheet is giving you the right numbers -
- The soldier course and the first course have the same radius (always measured at the bottom of the course) so they require the same number of bricks.
- It's 29 bricks instead of 24 because it assumes you are tapering your bricks. Look at column "P" - the inner width is 3.53". that's how you get to 29 bricks. I probably wasn't clear about this in the assumptions
- To the question about 29.2 vs. 29 1/2 bricks - the way I set it up, it gives you the bricks needed to the 10th of a brick. So realistically, if it says you need 29.2 bricks, you might use 29 bricks with a little thicker mortar gap. Or, you could (quite painfully) cut every brick a bit narrower to use an even number.
- Your comment about using half bricks - yes, but with tapering. The spreadsheet assumes the bricks are all standard width (usually 4.5 inches) at the back unless the builder enters a narrower width in column "R". I built in the ability to change this because I at some point almost every builder starts cutting the bricks into thirds or even smaller in order to make them easier to work with.
In the end, It's really up to the builder - but your questions are good ones to help understand how to interpret the calculations. I set the spreadsheet up to make the taper calculations really easy to do and very accurate. The brick counts were a by-product of that. But if you want to build an oven without tapering the bricks - then I'd look at the calculated radius for each course and use the math you propose to get to the brick count. It shoudl be quite easy for you to add a column to your own version of the spreadsheet that will give you this.
Does that all make sense?
I have a follow on question though - does this spreadsheet assume that you're only cutting the ends of the brick and have not cut angles to form the arch element (i.e. you're spacing the bricks with mortar rather than cutting an additional angle on the brick)?
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