BLL Associates Limited

B.L.L Associates Ltd are able to offer a wide and comprehensive range of services to our clients to assist in protecting your building from the effects by lightning, as briefly detailed below:-

Design

B.L.L Associates Ltd can carry out a full strike risk potential of your building and advise on the need to fit a lightning protection system.

Our Technical Department are available to assist clients in the detailed design of all lightning protection projects.

All survey, design and 'As installed' drawings are produced electronically using CAD systems.

Lightning Protection and Specialised Electrical Earthing Installations.

B.L.L Associates Ltd can supply, install and certify all types of lightning protection and earthing systems to the clients and British Standards requirements.

Surveys, Maintenance and Testing.

B.L.L Associates Ltd can carry out your annual testing of existing lightning protection systems, carry out detailed surveys and maintenance all in accordance with the current British Standards.

Specialised Earthing Systems

B.L.L Associates Ltd can supply, install and certify specialised earthing installations to clients requirements.

Roofing Contracting
Steeplejack and Specialised Access.
**Installations, Periodic testing & Inspections of safety Eye Bolts.**

B.L.L Associates Ltd are able to ofeer a full range of steeplejack services and specialised access to difficult locations.

Consideration on the need for surge protection is now a requirement of British Standard 5851.

B.L.L Associates Ltd can provide advice on the need for surge protection and if required can arrange for surge protection to be provided by a specialist surge protection installer.

Lightning Protection Equipment & Component Supply.

B.L.L Associates Ltd can supply Lightning Protection Equipment & components at extremely competitive rates.

Function of Lightning Protection Systems

Lightning is a natural hazard, being the discharge of static electricity generated in storm clouds. In the UK approximately 100,000 flashes strike the ground each year. Some strikes damage buildings either directly or indirectly by causing fires and explosions. A few kill or injure people and animals.

The provision of a lightning protection system to a building will not prevent a strike by lightning but will channel the strike current direct to earth via the roof network and down conductors and significantly reduce the likelihood of damage to the building.

BSEN 62305 parts 1-4 recommends that lightning protection systems should be tested and inspected at intervals not exceeding 12 months and during the inspection the bonding of any new plant or roof metalwork should be checked to ensure it is in accordance with the recommendations of BSEN 62305.

The principal components of a lightning conductor system are as follows:

• Air Terminations
• Down Conductors
• Joints And Bonds
• Test Joints
• Earth Terminations
• Earth Electrodes
• Surge Protection
• Soil Resistivity testing
• Site Evaluation/Risk Factors

Air termination networks may consist of vertical or horizontal conductors or combinations of both.

No part of the roof should be more than 5 m from the nearest horizontal conductor. For large flat roofs, this will be achieved typically by an air termination network mesh of approximately 10m x 20 (Faraday Cage).

The function of a down conductor is to provide a low impedance path from the air termination to the earth electrode so that lightning current can safely conducted to the ground.

An earth electrode should be connected to each down conductor. Each of these earths should have a resistance (in Ohms) not exceeding the product given by ten times the number of earth electrodes to be provided. The whole of the earth termination network should have a combined resistance to earth not exceeding ten ohms without taking account of any bonding to other services.