A jack arch divides tapered bricks above an opening. BrickCore calculates each brick and joint for a flat or cambered profile. The workshop starts with a depth of 10 cm.
Enter span, height, brick dimensions and joint width. Check the brick plan and connections. The PDF includes a complete overview, brick numbers and individual full-size cutting profiles with setting-out dimensions.
jack arch, flat arch
Measure the clear opening and required height above the frame. Choose brick size, bond, joint and a flat or cambered profile. For cutting, distinguish between upright and lying bricks.
The sloping joints point towards the setting-out centre. Brick widths therefore differ at the bottom and top. The layout accounts for that taper and for the joints; simply dividing the span by a brick width is insufficient.
In a straight measuring row of five bricks there are four joints between them: 5 × 5 cm + 4 × 1 cm = 29 cm. Count any joints at the two ends separately. In the jack arch, BrickCore then accounts for the sloping brick and joint faces.
A free account lets you view the calculation and drawing. The PDF contains calculated dimensions and cutting profiles; a download costs one credit. Follow the scale on the worksheet. Print full-size cutting templates at 100% with ‘fit to page’ disabled.