Air Terminals, Earth Rods & Surge Protection: Method Statement Requirements for Lightning Protection Contractors

Table of Contents

• Introduction: Method Statements for LPS Installation
• Phase 1: Air Terminal Installation
• Phase 2: Down Conductor Routing and Fixing
• Phase 3: Earth Electrode Installation
• Phase 4: Surge Protection Device Installation
• Phase 5: Testing and Certification
• What Your Method Statement Must Cover
• Frequently Asked Questions

Introduction: Method Statements for LPS Installation

A lightning protection method statement must describe each phase of the installation in a logical sequence, specifying the hazards and controls for each activity. Generic method statements that describe only the finished product — "we will install an LPS in accordance with BS EN 62305" — are rejected by competent principal contractors because they provide no assurance about how the work will be carried out safely.

This guide structures the method statement for a typical commercial LPS installation in five phases, describing what each phase must include and what your lightning protection RAMS must specifically document at each stage.

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Phase 1: Air Terminal Installation

Air terminals (lightning rods) are fixed at the highest points of the structure — typically the apex, ridge, or parapet of the roof. Your method statement for this phase must specify:

• Rooftop access route — How will operatives access the roof? Via internal stairs and hatch, external scaffold, or MEWP? Specify the access method, the equipment required, and the controls for that access method.
• Edge protection establishment — Collective edge protection must be established before any rooftop work begins. Specify the type (temporary barriers, installed safety rails, scaffold edge protection) and confirm that it will be inspected before each working day.
• Fragile surface management — Identify all fragile surfaces on the roof before work begins and confirm the procedure for managing them: marking (e.g., barrier tape), use of crawling boards, and the prohibition on accessing fragile areas.
• Air terminal fixing method — Specify how air terminals will be fixed: base mounted on non-penetrating weighted mounts, fixed through the roof covering with penetrating fixings, or fixed to a parapet or structural member. For penetrating fixings, confirm that the roof waterproofing warranty holder has been consulted.
• Sequence for ridge conductors — Describe how ridge conductors will be run from air terminals to down conductor positions, including fixing centres, tape clips, and separation from non-LPS metalwork.

Phase 2: Down Conductor Routing and Fixing

Down conductors carry the lightning impulse current from air terminals to the earth electrode system. They run vertically down the face of the building and must be specified in detail:

• Routing — Specify the planned route for each down conductor, avoiding routes through occupied spaces where practicable and maintaining separation distances from metalwork and services.
• Working at height on the building façade — Where down conductors run on the external face of the building, working at height on ladders, scaffold, or MEWP will be required. Specify the access method for each section of the route.
• Test clamps — Test clamps (disconnection points) must be installed at ground level on each down conductor to facilitate inspection and earthing resistance measurement. Specify their positions and installation method.
• Separation from electrical services — Down conductors must maintain specified separation distances from electrical cables, gas pipework, and other services. Your method statement must confirm that service drawings have been checked to verify separation compliance on the planned route.

Phase 3: Earth Electrode Installation

Earth electrodes (typically copper-bonded steel rods) connect the down conductors to earth. This phase carries the most ground-related hazards:

• Service identification — Before any rod driving begins, specify the service identification process: service plans obtained from the network operators and highway authority, CAT scanner (4-frequency mode) survey of the area, visual inspection for service markers, and consultation with the principal contractor on any known buried services not shown on drawings.
• Rod driving method — Specify the rod driving tool (electric hammer or pneumatic hammer), the rod specification (diameter, material, length), and the procedure for adding rod extensions when the first rod section does not achieve the target depth.
• HAV management — Specify the manufacturer's daily vibration magnitude for the rod-driving tool and the maximum daily usage before the HAV action value is reached. If usage will exceed the action value, rotation of operatives must be specified.
• Connection to down conductors — Describe how earth rods will be connected to down conductors via test clamps, including the minimum connection depth below ground level and the method for protecting connections from corrosion.

Phase 4: Surge Protection Device Installation

Surge protection devices protect electrical and electronic systems from overvoltages arising from lightning. Their installation involves interaction with electrical distribution equipment:

• Isolation assessment — Before installing SPDs in any distribution board, assess whether the board can be isolated. If so, specify the isolation and lock-off procedure. If not, document the live working justification and specify the controls (insulated tools, PPE, stand-by person).
• SPD selection confirmation — Confirm that the specified SPD is rated for the fault current of the distribution board, the voltage, and the protection level required by the BS EN 62305-4 design. Incorrect SPD selection is a common failure point on LPS installations.
• Cable routing for SPD connections — SPD connections must be kept as short as possible to minimise inductance. Your method statement should specify maximum cable lengths and routing requirements.

Phase 5: Testing and Certification

• Continuity testing — Test the continuity of every conductor in the LPS from air terminal to earth electrode, recording results.
• Earth resistance measurement — Measure the resistance of every earth electrode using a suitable earth resistance meter (fall-of-potential method or stakeless method). Record results against the design target.
• Bonding verification — Verify that all extraneous conductive parts required to be bonded to the LPS (structural metalwork, services entry points, metallic roofing) are connected and that connections are sound.
• Completion certificate — Produce an LPS completion certificate confirming that the system has been installed and tested in accordance with BS EN 62305. The certificate must be signed by a competent person and handed to the building owner.

What Your Method Statement Must Cover

• Phase-by-phase description of the installation sequence
• Access method and controls for each phase (rooftop, façade, ground level)
• Edge protection: type, establishment, daily inspection
• Service identification: plans obtained, CAT survey, consultation
• HAV: tool specification, daily vibration magnitude, EAV calculation, operative rotation
• SPD: isolation or live working assessment, PPE, cable length requirements
• Testing: methods, record format, acceptance criteria
• Certification: format and submission process

Frequently Asked Questions

What earth resistance value must we achieve for a UK LPS installation?

BS EN 62305-3 does not specify a single maximum resistance value — the required value depends on the LPS protection level and the soil resistivity at the site. However, 10 ohms or less is commonly specified for commercial LPS installations and is a widely accepted benchmark. If the soil resistivity is high (as is common in rocky or dry conditions) and a single rod cannot achieve the target resistance, the standard allows for a horizontal ring electrode or multiple rods in parallel. Always design to the target resistance specified in the BS EN 62305-2 risk assessment for the building.

Do we need a HAV assessment for all rod-driving equipment?

Yes, if operatives use rod-driving equipment for significant periods. Even a single day of rod driving can accumulate meaningful HAV exposure. Obtain the daily vibration magnitude (a(h,w)) from the tool manufacturer, calculate the exposure point value for the planned usage period, and compare to the EAV (100 points / 2.5 m/s²) and ELV (400 points / 5.0 m/s²). If the EAV is likely to be reached, rotate operatives and document the rotation plan in your RAMS.

Who can sign the LPS completion certificate?

The completion certificate must be signed by a competent person with appropriate qualifications in lightning protection. In the UK, membership of the Lightning Protection Association (LPA) or holding an ATLAS (Assured Testing in Lightning Air-termination Systems) qualification demonstrates competence. The certificate should reference the LPA Code of Practice and confirm that the installation has been inspected and tested in accordance with BS EN 62305.