Catalogs | Fences | F.A.Q. Frequently asked question - Notes & Warnings

Some suggestions on choosing the best fence for the end customer’s requirements are given below, together with some technical parameters normally used during installation.

Choosing a fence means fulfilling many requirements and preferences.

Firstly, it is dictated by the area to be fenced and its use: private residence, industrial facility, security-sensitive areas (e.g airports), arable land and cattle farms.

Above and beyond personal taste, preferences can depend on the spending budgets available. Generally speaking, every solution for the same use in the catalogue can be adapted to different price requirements.

Some examples and the implications that they entail, are given below.

MESH OR ROLLED FENCES

How do you choose between a chain link or spot welded fence?

Choosing a chain link fence is, to all extents, the only possibility when you want to fence an area on a slope. This is because the fence “follows” the lay of the land precisely, which a spot-welded fence could not do. If you want to install spot-welded mesh fencing rolls instead, when the slope is gentle, it will be necessary to set part of the fence in the ground, which will consequently not be parallel to the landscape.

How do you calculate the number of T-shaped or round posts?

Firstly, it should be emphasised that it is not advisable to use posts with a square section. The correct posts to use for rolled fences are T-shaped or round. In addition to the posts, you will need to calculate the number of mainstays, regardless of whether you opt for a rolled chain link or spot welded fence.

T-shaped or round posts must be placed every two metre (sometimes every 2.5 metre). Therefore, for a 100 metre linear fence, you will need 50+1 final post = 51 posts. There are two options for mainstays: 1 every 10 metre or 2 (if opposite-facing) still every 10 metre, “facing” 90°. For the corners, of any size area, you will need 2 mainstays positioned opposite the corner posts.

How do you calculate the height of T-shaped or round posts and the length of the mainstays to be set in the ground?

Generally speaking, the post must be 20-25 cm longer than the height of the fencing for a fence up to 150-175 cm. Above this height, an “extension” of 35-50 cm is recommended. The mainstays can mirror the height of the posts or be 20-25 cm shorter.

Can posts with bolted bases be used?

Rolled fences can also be installed on T-shaped or round posts to be bolted on. In this case, the mainstays will also be bolted on and a greater number is recommended, i.e. 2 pieces for every 10 metre of fence.

How do you calculate the length of the tension wires, ties and relative tensioners required for the installation of a chain link or spot welded fence?

“Runs” of tensioning wires depend on the height of the fence. Normally, you need a wire run every 50 cm. For example: for a fence that is 100 cm high, 2 runs of wire are sufficient; for a fence that is 150 cm high you will need 3 and for one that is 200 cm high, you will need 4 and so on.

Therefore, to calculate the number of rolls required (every roll is 100 metre long), you must multiply the length of the fence by the number of runs. For example, a 100-metre long fence that is 150 centimetres high, will need 300 metre of tensioning wire (3 rolls). How to do the calculation is shown below: 100 (length of fence) x 3 (No. of runs) = 300 metre.

The tie wire is calculated based on 1 roll up to 300 linear metre of fence. For longer fences, use the same proportions.

The tensioners to install a chain link mesh or spot welded rolled fence can be placed at a distance of 10 metre from one another, following the same calculation principle for the tensioning wires: (no. of runs x length of fence) / 10 + no. of runs

For example, for 100 metre of a 150 cm high fence = 3 runs x (100 metre ÷ 10) + 3 = (3 runs x 100 metre) = 33 pieces

PANEL FENCES

How do you calculate the number of uprights for a panel fence?

The number of uprights will the same as the number of panels + 1. The calculation refers to a “continuous run”. For example, a continuous fence measuring 100 metre in length will require 50 panels and 51 uprights (as in the most common case of 2.0 metre panels; with 2.5 metre panels, you will need 40 panels and 41 uprights).

If the same fence is interrupted by a gate, for example, two separate runs must be calculated. For the 1st run, for example, of 42 metre, 21 panels and 22 mainstays will be installed. The 2nd run of 56 metre (if the gate is 2.0 metre wide) will require 28 panels and 29 mainstays.

What kind of uprights can be used for a panel fence?

The uprights can be chosen from those in the catalogue, dedicated to a variety of panels (in spot welded wire, grids, with vertical picket infill, etc.).

If the ground is on a slope, walls of various heights must be erected which follow the lie of the land. The steps must have lengths (multiples of the panel to be installed) that are compatible with the size of the panels and consistent with the width of the fence chosen.

The uprights to use should not be pre-drilled (e.g. the ones for the WT series) because it is advisable to use collar clamps to secure the panel to the upright since the clamps can be positioned at different heights. In most cases, this will allow you to use one upright, the tallest, to support two panels to bridge the wall portions.

How do you decide between posts to be bolted on or set in concrete?

In some cases, the choice is dictated by a structure, for example, an existing perimeter wall around the area which requires the bolted version or the one to bet set in concrete, fitted with a round rod. In other cases, for a brand new installation, the version to set in concrete in the ground may be preferable. It is, however, a personal choice. There are also other types of posts to put up outside a pre-existing structure or wall.

What is the distance between fence panels?

Obviously, every panel has its own length. However, since you can choose between different posts and fixings, the distance between them when installing the fence will vary as a result. The choice of these elements depends on the spacing envisaged.

What are the features of the panels already fitted with uprights?

There are three panel fences consisting of a frame which includes the support uprights. These uprights can be set in concrete or bolted on. The main distinction is that every panel is self-supporting and, by studying the outline of the land to fence beforehand, it can follow (with some limitations </= 30°) a line that is not perfectly straight. Different heights and widths are available in the PoleFix series with a proportional price variation compared to the basic models. For the QuadraFix and RoundFix series, models made of standard perforated sheet metal measuring 2 x 1 metre, the prices will undergo bigger variations, regardless of whether they need to be smaller or bigger than the standard sizes.

PLASTIC FENCES

Why choose a fence made of extruded PVC?

The answer is simple: it depends exclusively on personal preference. A preference that takes into account that it will not need repainting for years, even with the limitations of a plastic fence.

GATES

How do you calculate the height of gates?

The height of the gate should always “equal” the height of the surrounding fence. You must, therefore, take into account a space allowed for it. In fact, if the fence is installed on a wall, the height of the gate must be calculated by adding the height of the wall to the height of the chosen mesh or panel. For example, if a 175-cm high fence is placed on a 25-cm wall, the gate must be 200 cm tall (25 + 175 cm).

Conversely, if the chosen mesh or panel rests on the ground, the height of the gate will the same as the fencing employed.

How do you calculate the width of gates?

Here again, a distinction must be made if the area is completely free or if there is a wall around it. In the first case, the choice of the end customer will be adopted. The customer will have to decide how much space - clearance - to dedicate to the entrance. If there is a pre-existing wall, it will be necessary to measure the free space from the wall in order to create a suitably sized gate. The width of a gate that can be positioned in the free space between two walls.

When considering gates, it is important to bear in mind that the space between the ground and the bottom of the gate leaf is a standard 100 mm. It will, however, be possible to create gates which leave more or less space between the ground and the gate leaf.

How to choose gate locks

All the gates are pre-configured to use two types of locks: YALE locks with relevant cylinder, also available with a single key for multiple gates; and MTS, suitable for KABA cylinders. The latter are commonly used in Switzerland. When placing the order, it is possible to request that the gate, both pedestrian and driveway models, is fitted with a CISA or similar electric lock. The opening direction must be indicated when placing the order.

The price of the locks and cylinders are not included in the price of the gates. It is standard practice not to supply KABA cylinders. Customers prefer to buy their own directly because it is often part of a locking system already installed.

PS The indications given here are drawn from our experience and standard practices adopted by our customers and installers. You can make different choices, however. What has been outlined so far is not a rule, but rather standard practice.

Notes & Warnings

The COMIVA Fence catalogue is the exclusive property of COMIVA srl.
The reproduction of texts, photos, drawings and formatting, even for internal use, is forbidden. The photos and drawings published are mostly produced by COMIVA. The others are the property of partners from whom we have received authorisation for their use. The materials, with prior written consent for their reproduction, can be used to illustrate our products whilst indicating the source.
COMIVA works constantly to ensure the best quality of it products. This publication should be used as a general guide for the purposes of indication.
COMIVA reserves the right to make changes, without prior notice, to the features of its products. All the information has been compiled with the greatest care. Nevertheless, inaccuracies or emissions may be encountered. The company assumes no responsibility for any damage caused by any printing errors or incorrect interpretations of this catalogue.