Self-assembly | Beves


Self-assembly of concrete fences - Installation manual

We have prepared a technical installation manual for you. We will also be pleased to explain everything about the instructions. While erecting a fence is not a kind of "rocket science", it is certainly a physical and time-consuming task to be taken into account. Last but not least, the involvement of a "handyman" who can cope with concreting and knows basic construction techniques is certainly necessary.

The procedure is summarised in the following steps:

  • Handling the concrete fence
  • Surveying the terrain
  • Calculation of the required material
  • Staking out the fence route
  • Digging holes
  • Setting the posts
  • Sliding the slabs

0. Handling the concrete fence

When handling and transporting the concrete fence, the following rule must be observed to avoid damage to the product (two pictures say more than a thousand words).  

1. Surveying the terrain

The first thing to do is to decide where the fence will lead to and from. When making your choice, you must take into account the legal provisions relating to buildings. Use stakes to mark the beginning and end of the fence, if your fence consists of several sections that are at approximately right angles to each other, mark these corners as well, if you want to build the fence in an arch, mark the location points of the individual slotted plots (see the article 4. Excavation of holes). If the fence is to run on a plane, then measure the distances between the individual stakes and write these distances down. If the fence will not run on a plane, but will descend or ascend a slope, the elevation of the land on which the fence will run must be measured. A hose spirit level can be used for measurement, but if the elevation is too great, or the rise is irregular, or the length of the fence exceeds the length of the spirit level, divide the slope into smaller sections and measure these.  

2. Calculation of the required material

Calculate the number of fence segments from the measured values (info: a segment contains 1 post and slabs). The number of segments of a section on a plane can be easily calculated:  In the case of a slope, you will first have to calculate the length of the section using the Pythagorean theorem: round the resulting number up to the next whole number and you have the number of segments. The required material is easy to  calculate:   * In the case of segments where there are not only flat slabs (but also, for example, radius or plinth slabs), calculate the number of different slabs separately. Do this calculation for each fence section.

Then calculate the number of end posts and corner posts - for each end of the section, calculate the end post and if two sections meet at right angles, calculate the corner post. Corner posts are not offered due to the weight for a 2.5 m fence, so count two end posts instead of one corner post.

If the number of segments multiplied by the axial distance results in a longer length than the planned length of the fence section, the slabs can be cut to the required length with a carbide grinder. The posts can also be cut.

3. Staking out the fence route

String a rope along each entire fence section to ensure that the fence is in line. The rope should be positioned so that it lines up with the front of the fence, or more specifically, the front of the posts. If you are building the fence in an arc (plan view), you probably won't need the rope.

4. Digging holes

The posts are set at a standard axial distance of 2.05 m for smooth posts and 2.07 m for patterned posts (see point 5. Setting the posts). The hole is dug to a depth equal to the length of the part of the post on which there is no slot. This length is variable according to the height of the fence:

For a 1.5 m fence post, the overlap without the slot is 70 cm (total post length 220 cm), so a hole of at least 70 cm must be dug.

For a 2.0 m fence post, the overlap without the slot is 75 cm (total post length 275 cm), so a hole of at least 75 cm must be dug.

For a 2.5 m fence post, the overlap without the slot is 90 cm (total length of post 340 cm), so a hole of at least 90 cm must be dug.

A concrete bed under the post in the hole is ideal, so dig the hole a few centimetres deeper, the concrete post will fit better into the level calculated for the segment (zero for flat ground, rebound for building a fence up a slope).

The hole should be 30-50 cm wide on average, depending on the subsoil into which you are setting the posts. A hole diameter of approx. 40 cm is sufficient for most implementations, approx. 30 cm for rocky ground and it is better to add 5-10 centimetres of width for loose soil, for example, after the soil has been compacted.

5. Setting the posts

It is ideal to start the installation of the fence from the end or corner. Dig a hole, pour a small amount of concrete as a concrete bed and set the first post. Make sure that:

the bottom edge of the slot is level with the chosen level for the segment,

the post is in a level position longitudinally and laterally, and

one side of the post is parallel to the stretched rope.

Secure the post with additional concrete, it is ideal if you are assisted by a second person to hold the post at the set position. As you backfill with concrete, smother it and check that the post is not falling, rising or leaning sideways. Dig another hole at an axial distance (e.g. 2.05 m for smooth posts or 2.07 m for patterned posts) and set another post in it. The ideal procedure is to prepare a wooden slab 2.01 m long (after sliding the concrete slab (see point 6. Sliding the slabs), you will have approx. 5 mm of space on each side of the concrete slab for the cement adhesive), which you insert into the slot and place the second set post on top of it. If you don't want to use wooden slabs, you will need a 2-metre spirit level. Use the spirit level to check that the bottom edges of the post slots are level, if not, compact the concrete to make the post rise a little higher or push it deeper until the concrete is cured.

Continue this for the entire length of the section. For the last post, if you are coming out with a space for a segment narrower than two metres, use a shorter spirit level, or cut a slab of approximate length to insert into the slots and level the post with the spirit level.

A quicker option is to immediately slide a concrete slab that has been painted with cementitious adhesive (see point 6. Sliding the slabs in) into the slots instead of the wooden slab, which you then level from below and line up.

6. Sliding the slabs

Once the posts have been set and the concrete has cured, the concrete slabs are placed. For the plane, this is simple - slide the slabs one by one into the slots. Position each slab in the slot with the design on the edge of the post (there is a clearance in the slot) and fix with cementitious adhesive (you can fix after all the slabs have been pushed in). Apply cement glue to the top of the slab and slide the next slab in. The use of cement adhesive is not necessary, but is strongly recommended as it gives the fence monolithic strength and ideal stretch and expansion.

In the case of a slope, sliding the slabs in is a little more complicated - if you have created a rebound, the slot on each side is at a different height. What to do about it? Simple help - cut a tooth into the concrete slab. Determine the height of the tooth as a ratio of the elevation and the number of segments in that section (or the number of bounces if you are not bouncing each segment, but several). So:

Because the slab is laid lower in the slot due to the tooth, the slot will remain bare at the top, so we recommend filling it with cement glue, you will get a much more aesthetic look.

Slide the slabs in slowly, be sure not to let them fall into the slot from a height, this will prevent them from being chipped or otherwise damaged.

The finished fence can be painted with facade paint.

NOTE: This manual is provided as it is, all procedures recommended herein are subject to change depending on conditions and their use is always at the personal discretion of the installer. The techniques described herein are not binding and are not the only procedure for installing a concrete fence. The author assumes no responsibility for damage caused by following the instructions in this manual.