Jake

Photo taken 2nd Dec '10

Jake is now building a corbelled brick cone

Drawn by Anne 2nd Jan '11

1st Attempt
Photo taken 14th Jan '11

2nd Attempt
Photo taken 18th Jan '11

3rd Attempt
Photo taken 20th Jan '11

Three brickwork tutors say this is stucturally sound and correctly bonded

so it should work ...

Photo taken 21st Jan '11

And now for the Maths!

Drawn by Anne Jan '11

The drawing shows some corbelling. Note that only the left-side is properly bonded. The right-side would need ¾ cuts

The 1st course is one brick wide, or 215mm, which is the same as two headers, plus 10mm joint

The 2nd course is increased by a Queen Closer + 10mm



Look carefully at the drawing and you'll see there are two perp-joints in the 2nd course

So the 2nd course is two Headers, plus their 10mm joint and then a Queen Closer, plus its 10mm joint

As can be seen the Size of a Queen Closer is 46mm

Calculating length of 2nd Course

Header          102½
Perp Joint        10
Queen Closer   46
Perp Joint        10
Header          102

Total             271mm

Difference between 2nd course and 1st course

271 minus 215 = 56mm

so the corbelling on each side is 56 divided by 2 = 28mm

Drawn by Anne Jan '11

From the picture, you can see the 2nd course has gained a Queen Closer and a 10mm joint

46 + 10 = 56mm

The 3rd course is 1½ bricks or one stretcher with its joint, and one header

225 + 102½ = 327½




Double-Check

Difference between 3rd course and 2nd course

327½ minus 271 = 56½mm

Which is good enough for me!

Drawn by Anne Jan '11

As can be seen, the 4th course is 1¾ bricks

And the 5th course is 2 bricks

which is 440mm

1st Course   = 215

2nd Course  = 271

3rd Course   = 327½

4th Course   = ? ? ?
5th Course   = 440

What is the size of the 4th Course?
It is in the middle of the 3rd and 5th course

440 - 327½ = 112½

112½ divided by 2 = 56¼

327½ + 56¼ = 383¾

Photo taken 27th Jan '11