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How to build a brick arch; the beauty, mathematics and history of building arches in architecture
Cologne Cathedral arches
How to build an archway of books or bricks
Great invention of the age: Arches appeared in buildings in Mesopotamia (Iraq) over 4000 years ago. They did not pop-up in Europe for a further 2000 years.
The innovation of the arch: Those who study new ideas call the use of new ideas "diffiusion of innovation". Innovations can transform cultures and economies.
Muslim masonry know-how, expanded into Europe from about 1200. Hundred of huge, amazing churches were built in a 100 year rush of construction; the masonry innovation spread eastward across Europe; a series fantastic cathedrals were built in isolated villages with the use of mysterious funds and highly controlled knowledge. This was the dot com boom of its time, and its code-writer wizards, the Masons Guild.
Arch enters Indian architecture: Equally amazing constructions appeared in India. Arch-know-how also expanded west from the middle east, into India.
The History of the Gothic Arch
Arch enters European architecture
The 1100 period period was one of warmth; and recession of ice and rise in sea levels. English Christians lost control of Jerusalem; and returned to Europe with lots of loot, and new knowledge. Coastal peoples took to the mountains, the passes and the oceans and invaded others. Mountain people were able to march over the mountains and invade other peoples. The period was followed by the little Ice Age which set in about 1250. So the times of the late 1100 and early 1200 recorded wars and innovations amid surges of capital and control.
Arches at the Alahmbra in Spain
Muslim builders used arches, vaults and domes, on columns and pyramidal towers or slender spires, called trabeate. This image above shows arches from the Alahmbra in Spain built at a time of Muslim control of the area.
MUST HAVE book on sacred geometry. The first chapter will amaze you!
Indian architecture before the use of the arch
Arch of books
Try this fun animation to understand the forces of the arch
- BBC - History - British History in depth: Build an Arch Animation
Find out how medieval masons built cathedral arches
How to fix a wobbly arch. Add buttresses
Voissoirs; angled bricks to make the curve of the arch
To make an arch the builder needs tapered bricks called voussoirs.
Order your voussoirs: Tapered voussoirs can be cut at the job site or ordered from the brick manufacturer.
Brick manufacturers produce tapered arch brick for the more common arch types. In modern construction arch support is sometimes provided by a steel angle or arch. Some say this use of a steel arch leads to careless masonry.
Make it waterproof: In the modern arch, flashing makes it leak-proof; installed below the arch and above the window framing or steel angle lintel , turned up to form end dams; termed tray flashing.,
The method of constructing an arch is similar for all types of arches
How to build an arch
First, draw your arch: The central key brick has an equal number of bricks on either side. Arch shapes are usually drawn full size either on a sheet of plywood or hardboard. Once the span and the depth of the arch are known the arch is drawn with trammels and a lath.
Two curves representing the intrados and extrados of the arch are drawn from a centre point along the springing line. These are cut out and framed with timber and used to support the arch as it is built-up known as an arch centre.
- A true arch pushes outward at the base; so it needs buttresses or abutements so the forces don't push the base apart.
- The arch frame - usually of of wood shapes underside of the arch before the addition of the final cornerstone. This is known as a centre or centring or the arch centre. In older times these drawings for temple and churche planning were scribed full size on a floor covered with a layer of plaster, with giant compasses.
- Voussoirs - bricks made or cut into a wedge shape - are laid on the centre until the arch hold its self up. The angle of the voussoir brick for each arch project differs depending on curve of the arch. For the semicircular arch you can do it yourself and cut standard (215x102x65) bricks into voussoirs to the angle found in the drawing for the curve you want.
The simpler way - just order Voussoirs, by angle from the brick works. These are voussoirs, (vuswaars). They come in standard angles, or you can order special ones.
- The interior curve edge of an arch is known as the intrados and the interior surface the soffit.
- Extrados mean the outer curve.
- The clear space means the width of the span and widest point.
Brick arch with wooden centre still in place
A ready-made lighted arch
If DIY Voussoirs - Nominal face dimensions of arch brick, in (height by width)
Minimum Permissible Radius of Arch to Intrados, ft
Min Permissible Arch Brick, in. Radius of Arch (height by width) to Intrados, ft
4 x 22⁄3
8 x 22⁄3
12 x 22⁄3
16 x 22⁄3
4 x 31⁄5
8 x 31⁄5
12 x 31⁄5
16 x 31⁄5
4 x 4
8 x 4
12 x 4
16 x 4 20.7
Arch Literacy Test
The underside of an arch is called the
Camber: The relatively small rise of a jack arch.
Centering: Temporary shoring used to support an arch until the arch becomes self-supporting.
Crown: The apex of the arch’s extrados. In symmetrical arches, the crown is at the midspan.
Depth: The dimension of the arch at the skewback which is perpendicular to the arch axis, except that the depth of a jack arch is taken to be the vertical dimension of the arch at the springing.
Extrados: The curve which bounds the upper edge of the arch.
Intrados: The curve which bounds the lower edge of the arch. The distinction between soffit and intrados is that the intrados is a line, while the soffit is a surface.
Keystone: The voussoir located at the crown of the arch. Also called the key.
Label Course: A ring of projecting brickwork that forms the extrados of the arch.
Rise: The maximum height of the arch soffit above the level of its spring line.
Skewback: The surface on which the arch joins the
Skewback Angle: The angle made by the skewback from horizontal.
Soffit: The surface of an arch or vault at the intrados. The soffit is the interior surface
Span: The horizontal clear dimension between abutments.
Spandrel: The masonry contained between a horizontal line drawn through the crown and a vertical line drawn through the uppermost point of the skewback.
Springing: The point where the skewback intersects the intrados.
Springer: The first voussoir from a skewback.
Spring Line: A horizontal line which intersects the springing.
Voussoir: One masonry unit of an arch.