Round arches are one of the style-defining elements of buildings. No wonder, therefore, that the round arch is always very common even in private buildings. Although some instructions on the Internet should suggest that the walls of a round arch is not difficult - there are some basic rules and subtleties, however, there are still to pay attention.
The structure of the arch
Before you begin to build a round arch, you should first deal with the structure of this element. Below you will find the most important parts and names of parts of a round arch.
- arch back: top of arch
- arches: front of arch
- flocks: individual stones
- capstone: final razor stone
- abutment: on the outside of the arch (especially important for the segment arch)
- the clear dimension: the lower and outer respectively Point of contact of the last flocks
- center of the arch: the center of the imaginary circle of the arched section (lies clearly below the arch)
In addition to the typical arched arches there are also some special forms. Below are the conventional bow shapes.
- segmental arch
- arched arc
The segmental arch corresponds to a partial section of the circumference and is therefore more elliptical. Due to the design, the weight acts from above and is mostly derived laterally under thrust. Corresponding abutments must therefore be taken into account on the pillars.
The round arch forms a semicircle with the outermost end stones lying flat on the pillar. The force is derived via the round arch directly vertically into the pillars. Thus, the lateral thrust forces are less formed.
The basic procedure for building a round arch
They always start from the outside (from both sides) and work towards the middle of the arch. The last stone is then always inserted in the middle. He is chosen from the fit very tight and can also be wedge-shaped, in order to derive the weight better on the two sides of the sheet can. Since the hosts are always symmetrical up to the keystone, ie the same number on each side, the number including the keystone is always odd.
Step-by-step instructions for building a round arch
- Sharp stones (bricks, concrete, bricks, natural stones, etc.)
- Mortar (according to the bricks to be walled)
- Formwork wood
- Nails or screws
- possibly spacer wedges
- Drilling machine with whisk
- Mortar bucket
- Mason's hammer
- possibly rubber mallet
- guide cord
- plumb bob
- Tool for the bow gauge (screwdriver, hammer, saw, etc.)
1. Preparatory work
Explicitly with round arches, the planning is always in front of the wall. This also means a construction drawing that takes all measurements to scale. Based on the plan, you then create your shopping list and get all building material.
2. Set abutment
For segmental arches you need a pronounced abutment. This is usually formed by the corresponding beveled pier point. Herstellung 3. Making the sheet gauge
Now cut the round sheet gauge from your formwork timber. For very wide and heavy arches, you should cover the entire surface with a wooden profile. For smaller arches, the lateral arches are usually sufficient as a front and rear support point. Das 4. The Walls of the Round Arch
You start by setting the flocks left and right at the end of the bow. First, make a mortar joint bed. For a round arch with average clear dimensions of conventional door widths, the gap at the soffit should never fall below 0.5 cm. At the back of the arch, the joint width should not exceed two to three centimeters.
5. Put the capstone
Now put stone by stone. On each newly set stone, you distribute the mortar for the next stone until you then set the capstone.