Hi! We designed and are building our own home. I have a bachelors in art, but nothing to prepare me for this task. I know what I think about architecture when I see it, but am a little nervous trying to foresee the vision. I wondered if you have any wisdom you could share with me about brick arches and mixing different types. Maybe some basic arch design "rules" to go by. More specifically, if I have a few segmental arches (above windows, garages doors, and to the side of the porch/entrance), is it taboo to use a Roman arch at the front of the porch/entrance? If this is too vague, I apologize, any opinions would be appreciated. Our brick layer is awesome, but ultimately he would like to do the work and for us to make the choices. Secondly, how wide can either of these types of arch be without compromising strength if? Thanks, Tacy
Thanks for your question Tacy.
The original brick arch was conceived by the Romans. It was a pure half circle. The use of a brick arch was only possible with the newly discovered mix of concrete at the same time. The Greeks had barrel vaults built of all stone before that.
Depending on the thickness of the wall (usually an inner and outer brick course with concrete in the middle) the Romans could build 40-60 foot wide arches.
These are not the arches that we concoct as just veneer over wood frame buildings. The strength of a free standing arch should be determined by a structural engineer.
The Moors and Middle East builders took two segments and joined them at a point, which also had some strength but built with thick masonry and concrete as well.
The French tested segmental arches and used heavy blocks of stone and trim pieces that rested on short spans.
Mixing the segmental and Roman arch is not considered "proper" but it is done quite a bit in contemporary residential architecture and just before the turn of the century architects experimented quite a bit with both during the Beaux Arts period where eclectic design came about breaking the 'rules' somewhat and a mix of styles was attempted.
I have used a roman arch at an entry porch with segmental windows on French style houses especially. I will never introduce a segmental arch onto an Italian style villa, etc.
The way the pure arch works is that on each bearing side there should be enough mass and resistance to hold the arch from falling or breaking into and cracking the side supports. This means a completely masonry wall construction of one foot or more in thickness in order to counter the thrust of the arch, especially segmental which is weaker than a Roman arch.
Modern veneer arches of large spans are normally supported by steel curved lintels.
Let me know if I can be of further assistance, John Henry