Buyer’s Guide For Construction Safety Net
Construction safety nets have become an indispensable part of the construction industry. Whether it is a high rise building or any other constructional work these nets ensure the safety of the people working in the construction site and act as a preventive measure in case someone falls. These nets are the safest fall prevention mechanism and have become extremely popular around the world due to its practicality, affordability and safety aspects it brings to the construction sector.
What Are Construction Safety Nets?
Made from high-density polyethylene (HDPE) construction safety nets are also known as one type of construction safety equipment and can be used by either installing them horizontally or vertically as per the position, size, shape and height of the building under construction. The ideal way to use it is by wrapping the whole construction site from the button to the top so that it acts as a protection system or wall and can stop anything from falling down without blocking the view from inside or outside. However, you need to have professional skills and technical knowledge for installing construction safety nets at the building or construction site.
Features of Construction Safety Nets
So, in this particular section, we are going to talk about certain things that are inextricably related to construction safety nets. At the same time, we will let you know the functions as well as applications of these items. Well, these are called anchorage devices and these are used to connect the construction safety net to the structure. We have elaborated these items here, so have a look at the following points:
- Anchor Point: Anchor point is a kind of fixing point which is adhered to the structure. After fixing it on it, safety construction nets are attached to it. It provides solidity to the net.
- Border Rope: Border rope is used in order to determine the overall dimension of the net. It is generally passed through every mesh around the perimeter of the construction safety nets.
- Catching Width: Catching width is basically the distance between the outer edge of the construction safety net and the edge of the work platform.
- Characteristic Load: Anchor point is designed to carry a specific load. Now, the characteristic load is another important point through which the maximum capacity which can be carried by the anchor point is calculated.
- Class: The class of construction safety nets entirely depends upon the capacity of energy absorption and mesh size of the construction nets.
- Clearance Distance: If anyone falls on the construction net, it will certainly deflect because of the impact of that person. Therefore, clearance distance refers to the distance between the ground and the net. It must be cleared so that the person does not get any kind of physical injury after falling on it.
- Competent Person: In order to use construction safety nets, you must be competent enough. A person must acquire proper training as well as knowledge before getting into this field.
- Coupling Rope: Coupling rope is a very important part of the construction safety net as it is used in order to join to different safety nets together.
- Eaves Bagging: If there is any unsupported perimeter in the construction safety net, eaves bagging is used. It is a kind of rigging technique that is used to obstruct the waisting of a safety net.
- Fall Height: Fall height refers to the vertical distance between the construction safety net and the work platform.
- Initial Sag: Initial sag is the amount of sag that happens due to the self-weight of the construction safety net.
- Mesh: Mesh is basically a series of ropes that are arranged to form the safety net. It is arranged in different patterns such as diamond and square.
- Mesh Rope: Mesh rope is used to prepare the meshes of the safety construction nets.
- Mesh Size: Mesh size refers to the distance between the center of the mesh and the center of the safety nets.
- Net System: The construction safety nets, supporting structure and the anchorage devices are linked together in such a way so that it can collectively make a fall arrest system and this is called the net system.
- Safety Net: Safety net consists of labels of the net, mesh, test meshes, and border ropes.
- Supporting Structure: A supporting structure is needed to which you can attach the construction safety nets.
- Test Mesh: Test mesh is a separate mesh that is attached to the construction safety nets and the material which is used to make mesh rope is also used to make test mesh. It can also be removed in order to test the UV deterioration of the construction safety net.
- Tie Rope: The tie rope is used in order to secure the border rope to one of the anchor points of the structure.
- Waisting: Earlier, we have mentioned this word but, what ‘waisting’ actually is. It is generally the effect which is generated after pulling away from the safety construction net horizontally from the structure. In other words, we can say that it is the safety net’s intended perimeter and it might happen because of the over-tensioning of the net or the self-weight of the safety construction net at an unsupported edge can be another reason behind ‘waisting’.
Types of Construction Safety Nets
Well, we can classify construction safety nets based on BS EN 1263 standards. Now, if you don’t know what BS EN 1263 is, you don’t have to worry as we have elaborated it here. So, go through it before knowing the classifications of construction safety nets.
BS EN 1263: BS EN 1263 is the present European standard for installing as well as testing safety nets. It basically consists of two important parts- first is ‘Safety requirements test methods’ whereas the second one is called ‘Safety requirements for the positioning limits’. In order to protect the workers from the deeper fall, this European standard is applied to construction safety nets and its accessories which are otherwise known as anchorage devices.
Based on the present European standards, construction safety nets are classified into four classes- Class A, Class B, Class 1 and Class 2. Class A and B refer to the maximum capacity of energy absorbed by the safety nets whereas Class 1 and 2 indicate the sizes of mesh. The energy absorption capacity of Class A1 and A2 is 2.3 kilojoules or kJ and for Class B1 and B2, it is 4.4 kJ. On the other side, the mesh size of Class A1 and B1 is 60 mm and for Class A2 and B2, it is 100 mm.
If you are looking for system S safety nets, you must go for class A1 and A2. The mesh size of Class A2 is 100 mm and therefore, the initial sag of this class is lesser than others.
Standards of the Anchorage Devices of Construction Safety Nets
- Mesh Rope: It is clearly mentioned that three different strands should be used to make the mesh rope and separate strands are used so that it becomes difficult to unravel the mesh rope. Moreover, it should be tested as per the clauses 7.3 of BS EN 1263-1.
- Border Rope: Earlier, we have mentioned what mesh rope is and how it works. According to clause 7.5 of BS EN 1263-1, the tensile strength of a mesh rope should be 30 kN. Well, it is the minimum range and therefore, anything below it is strictly prohibited.
- Tie Rope: Tie rope is basically used to fasten the construction safety net to the anchor points or the structural elements. According to clause 7.5 of BS EN 1263-1, the minimum tensile strength of tie rope should have 30 kN.
- Coupling Rope: Sometimes, one construction safety net is not adequate to cover the whole construction area and therefore, the coupling rope is used to join two safety nets together. The minimum tensile strength of the coupling rope should be 7.5 kN as per clause 7.5 of BS EN 1263-1.
- Safety Net Label: The label of safety net should consist of the date of manufacture, article code, and name of the manufacturer, size and class of net, configuration and size of the mesh, serial ID or unique identity of the safety net, energy absorption capacity and type of net inspections. According to the European safety standards, the label must adhere to the safety net permanently and it should have the legibility throughout its whole life.
- Removable Test Mesh: Test mesh is used for testing UV deterioration of the construction safety nets and as per the European safety standards, this test must be done once in a year and therefore, three test meshes should be loosely attached to the safety nets so that it can be easily removed whenever it is required. According to BS EN 1263-1, it must have the same ID number and the same material must be used to make this. Moreover, it should have a label that will show the previous test report and the energy absorption capacity and the label should have 12 months of validity.
- Size Of Safety Nets: European Safety Standards BS EN 1263-1 is only applicable if the size of the safety net is 35 m2. Although the shortest size of such a net is 55.0 meters, it is not heavily used. According to the European Safety Standards, if the fall height is more than 2.0 meters, a minimum 35 m2 construction safety net is required and along with this, it should have 2.5 meters of minimum fixing space. However, if the size of the construction safety nets is less than 35 m2, it means there will be more energy absorption and less deflection. Therefore, in such a case, you must use a Class B safety net as its energy absorption capacity is 4.4 kJ.
- Fall Height: Earlier, we have mentioned what fall height is. However, it is the most important point related to construction safety nets. We will recommend you reduce fall height as much as possible and therefore, the distance between the work platform and construction safety nets should not exceed 2 meters. Although European Safety Standards allow you 6 meters of fall height, it is only applicable if the size of the safety net is 35 m2. The outer edges should be within 3 meters of the work platform as the edges as well as the corners cannot deflect as much as the center.
- Clearance Distance: The calculation of clearance distance is completely based on the fall height. However, if the fall height does not exceed 6 meters and the size of the safety net is 35 m2, it can be easily calculated. According to BS 8411: 2007, there should always have an extra 0.55 meters of clearance distance below the net.
- Initial Sag Or Net Sag: Initial sag or net sag is the effect that happens because of the deformation from net’s weight. The initial sag should be within 5% to 10% and in order to get an adequate amount of initial sag or net sag, the size of the safety net must be 10% larger than the ground it will cover. Excess nets should be rolled tightly into the attachment system or tie rope. It will help you to avoid excessive stress on the meshes and the load will be evenly expanded on individual meshes.
- Under-tensioning and Over-tensioning: If the safety is net is under-tensioned, it will deflect so much that the falling person might hit any obstacle if there is not enough clearance distance. On the other side, if the net is over-tensioned, there will not be enough deflection and the whole load after falling a person will be imposed on the structure and the construction safety nets as well.
- Catching Width: If anyone falls from the work platform, two aspects will work- forward movement and downward movement. The more the fall height is, the more the forward movement will be. Therefore, the net must be installed in such a way so that it can handle the forward movement of the falling person. The width between the outer edge of the safety construction net and edge of the work platform is called catching width. According to BS EN 1263-2, the catching width must be 3 meters if the fall height is 6 meters.
How You Can Find Good Construction Safety Net Supplier?
It will not be very difficult to get a good construction safety net supplier. The importance of the safety net has increased so much that it is easily available online as well as offline stores. However, different companies supply different types of construction safety nets and therefore, before buying safety nets for your construction, you must set the requirements. There are many companies that can form safety nets based on your requirements. Moreover, it is the duty of a good construction safety net supplier to give an installation manual along with the safety nets. If any supplier does not give you such a manual, you should ignore them without any hesitation. However, if you are planning to buy it online, Alibaba will be the option as it will give you a 100% refund if there is any sort of defect in the safety nets. Moreover, there are some other companies that supply high-quality construction safety nets and these are anbuppe.com etc.
Planning Before Installing Safety Nets
The supplier, as well as the workers, must be involved in the plan of safety nets installation. You must consider the following aspects while installing construction safety nets:
- The rigging or installation or striking or dismantling sequence.
- Anchor points must be located.
- Clearance distance must be accurate.
- There should always be a rescue plan
- Roofing contractor, main contractor, net installer and designer must be involved.
Role of Designer
The designer will do the following things:
- Designing of suitable anchorage points
- Avoiding the details that will make the safety net installation process dangerous as well as difficult
Role of Installer
The installer will install as well as dismantle the safety nets. The installer will also give the following information to the site supervisor or the main contractor:
- Information regarding their qualifications as well as training for installing the construction safety nets.
- The energy absorption capacity, maintenance and testing report of the nets.
- The plant they are going to use for installing the safety nets.
- The requirements for anchor or fixing points
- They will give the rescue plan and how the falling person will be protected below the net.
- They make sure that the anchor points are perfect for the loads and at the same time, they make sure that there is enough clearance distance
They also give verbal instructions to everyone involved in this process and at the same time, they give a document where the inspections procedure, as well as the rescue procedure, is elaborated.
Role of Site Supervisor or the Main Contractor
The site supervisor or the main contractor does the following things:
- Provide access for the safety nets installation
- Provide anchorage points
- They provide suitable ground conditions so that mobile access equipment can be easily set up.
- They make sure that all the workers are properly trained for the rescue program.
Several Things That You Must Consider To Minimize the Risk of Safety Net Rigging Process
There are certain things that must be considered to minimize the risk of rigging process and these are mentioned below:
- Remote anchorage attachment must be used at ground level.
- MEWP or Mobile Elevating Work Platform must be used
- A ladder must be used for short-duration work.
- Rope access techniques must be there. ( it is a very specialized technique and therefore, only competent as well as train persons should use this)
Importance of Using Construction Safety Nets on Construction Site
A collective fall arrest system is required if it is a high-level work area. Collective fall arrest consists of the following points:
- Fall arrest mats or soft landing systems
- Safety nets
Construction safety nets are being heavily used on construction sites because of its endless benefits which are mentioned below:
- Safety nets are very useful for high-level work areas as it cuts down the falling distance of a person from the work platform and ultimately, it works as a lifesaver.
- Safety nets are designed in such a way so that they can easily absorb the energy created because of the fall of a person. It can deflect the energy and therefore, the falling person does not get any sort of physical injury.
- It is clearly mentioned in the instruction that comes with construction safety nets that there must be adequate clearance below the net. If the clearance distance is maintained, the falling person will not hit any obstacle after falling on it.
- Construction safety nets boost the confidence of the workers and therefore, the workers do not have to restrict their physical movements while working at height after installing safety nets.
The people involved in this process must have done all the practicable steps set by The Health and Safety in Employment Act which is otherwise known as the HSE Act 1992. People who are included under this law are as follows:
- Employers: The duty of the employer is to ensure a suitable working environment and at the same time they have to make sure that the plant which is used by the employees is made as per the HSE Act.
- Self Employed People: The role of self-employed people is to ensure that no harm will be caused to anyone.
Some Standards That Must Be Followed
- BS 8411: BS 8411 is a code of practice which is used on construction sites
- BS EN 1263-1 And BS EN 1263-2: These are European Standards used for safety construction nets. The first one is used for test methods whereas the second one is used for the positioning limits.
There is no doubt that construction safety nets have become an integral part of construction works. It is the only thing that is capable of giving collective protection for the workers and at the same time, it offers passive protection. It means that workers do not have to do anything to keep them safe in a hazardous area. So, this is all about construction safety nets and you must bring it if you are involved in such work.