EXTERIOR CLEANING & HIGH LEVEL ROOF AND GUTTER CLEANING
Ministry of Defence (MOD) - Odiham, Hook, RG29
Client's Challenge
RAF Odiham required an urgent exterior cleaning programme across multiple buildings and hangars that had fallen outside routine maintenance for several years.
Environmental pollution, algae growth, black mould and organic contamination had built up across rooflines, gutters and façade elevations. In addition to impacting presentation, blocked gutters and drainage routes were causing grey-water overflow, increasing the risk of long-term damage to building fabric if left unresolved.
The works needed to be delivered within a live operational military airbase, requiring strict adherence to safeguarding, airside working protocols, and Health & Safety compliance, all while ensuring zero disruption to aircraft operations and personnel movement.
Assessment & Planning
APT ICC carried out a full site survey in collaboration with MOD Estates and Health & Safety teams to assess:
• Extent of biological growth and pollution staining across buildings and hangars
• Roofline, façade and gutter access requirements
• Working-at-height risks and absence of permanent anchor systems
• Live airside operational constraints and safeguarding controls
• Controlled working zones and exclusion requirements
A phased exterior cleaning plan was developed, sequencing works to maintain operational safety, comply with MOD airside regulations, and allow cleaning to progress without interfering with aircraft movement or base activity.
Methodology
Step 1: Operational coordination and access control
APT ICC established controlled work zones, exclusion areas and airside safety measures, ensuring compliance with MOD safeguarding and operational requirements before any high-level works commenced.
Step 2: Rope access deployment for high-risk and restricted areas
IRATA-trained rope access operatives were deployed to access complex rooflines, façades and gutter runs where MEWPs were impractical or unsuitable within the airbase environment.
Step 3: Manual clearance of moss and organic debris
Loose moss, vegetation and organic material were manually removed from roof and gutter areas to prevent blockages and prepare surfaces for treatment.
Step 4: Algae and mould treatment
A targeted application of specialist algae treatment was applied to roofs, gutters and building elevations to break down biological growth, staining and mould contamination.
Step 5: Controlled rinsing and soft washing
Low-pressure water application and controlled jetting were used to rinse treated surfaces, restoring the building finish without damaging metal roofing, cladding or drainage systems.
Step 6: Drainage reinstatement and minor maintenance
Gutters and downpipes were checked to confirm free flow, with localised roof
and gutter repairs completed where required to ensure long-term drainage
performance.
Step 7: Preventative maintenance guidance
Following completion, APT ICC provided guidance to MOD Estates on implementing a planned maintenance programme to reduce future build-up and protect building fabric long-term.
Site Access & Logistics
Equipment
• IRATA rope access systems for high-level and restricted access areas
• Controlled low-pressure washing equipment
• Roof and gutter clearance tools
• Full PPE and airside-compliant safety equipment
Chemicals
Algae Free – specialist exterior algae and biological growth treatment for roofs,
gutters and façades
The Results
• Significant improvement in the appearance of buildings and hangars
• Effective removal of algae, mould and environmental staining
• Gutters and drainage routes restored to clear, functional condition
• Reduced risk of grey-water overflow and long-term structural damage
• Safe completion of works within a live airside military environment
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