Why is a flat arch called an arch if it is flat?

woody7777

A friend of mine has a house with what he calls flat or camber arches over his doors and windows. I thought an arch had to be curved. Why would they be called arches. He didn't seem to know.

grumbler

Because they work like arches - hold the wall above without a lintel.

Section62

woody7777 said:

A friend of mine has a house with what he calls flat or camber arches over his doors and windows. I thought an arch had to be curved. Why would they be called arches. He didn't seem to know.

In building terms an 'arch' is a way of forming an opening using masonry units in a self-supporting manner.  The design transfers the load above into an outward (sideways) thrust, which is resisted by the masonry to the side of it. (compared to a lintel or beam where the loads are typically transferred by 'simple' support)

Flat or camber arches work by shaping the masonry so it works in the same way an arch does, but with a level or near-level soffit.

'Arch' as a curved shape is just used as a shorthand to describe something which looks like a traditional arch.

stuart45

As Section62 said the bricks are shaped. A Camber arch is really a Segmental arch with the top and bottom extended to make it appear flat. It's set out on an arc from a striking point much lower than other arches.

GDB2222

I need to insert some text here ...

stuart45

You forgot the Venetian arch

woody7777

Thanks everyone, I think I understand it now. Looks like a lot of work to build an arch.

theoretica

Section62 said:

'Arch' as a curved shape is just used as a shorthand to describe something which looks like a traditional arch.

Which is very unsatisfying as the word comes from the latin for bow (as in archery).

stuart45

Used to be when you had to draw the arch out full size, then make cutting boxes and cut all the bricks to size. Nowadays you can order them readymade. 
Brick Cutters – Brick Cutting Services – Brick Arches — Brick Cutters in Sussex (ajbrickcutters.co.uk)