Fencing

Acoustic fencing: realistic insertion loss figures (15–18 dB heavy close board; up to 25 dB composite panels), BS EN 1793 limitations, flanking path elimination as the critical factor, heavy close board specification as cost-effective alternative to branded acoustic products

Concrete posts and gravel boards: slotted vs morticed vs plain post types, 100×100mm minimum section, C20 concrete at 600–750mm depth, 250mm hole diameter, concrete gravel board slot systems, clay soil installation, post cap specification

Electric gate installation: Supply of Machinery Regulations 2008 (installer as manufacturer), Declaration of Conformity requirement, BS EN 12604 force limits (400N peak), BS EN 12978 safety devices, risk assessment zones, underground vs articulated arm actuator selection, Part P for 230V supply

Feather edge board installation: BS 1722-5 25mm minimum overlap, one-nail rule (never pin adjacent boards), board coverage calculation, UC3 treatment, arris rail layout, capping rail, maintaining vertical alignment across a run

Fence post depth: one-third rule (600mm for 1.8m fence), C20 concrete in 250mm diameter hole, Postcrete alternative, clay and sandy soil adjustments, string-line level setting, bracing during cure, post length calculation from fence height

Fence repair and post replacement: concrete and steel repair spur installation, diagnosing rot vs shallow setting, full post break-out method, arris rail repair with brackets, gravel board upgrade opportunity, cost comparison of repair methods

Metal railings and gates: duplex coating specification (galvanising + powder coat) for UK exterior, coastal aluminium alternative, post setting methods, Machinery Directive compliance for powered gates, wrought iron and cast iron repair techniques, lead paint safety

Planning permission for fences and walls: GPDO 2015 Schedule 2 Part 2, 1m adjacent to highway, 2m elsewhere, Conservation Area 1m limit, Listed Building Consent requirement, Article 4 Directions, trellis topper height calculation, Scotland/Wales differences

Timber close board fencing: BS 1722-5 specification, 100×100mm posts at 600mm depth, three arris rails for 1.8m, UC4/UC3 treatment, gravel board requirement, capping rail, common failure modes and longevity expectations

Trellis and panel fencing: BS 1722-11, standard 1830mm panel widths, post spacing from measured panels (not catalogue), lapped vs woven vs feather-edge panel types, planning permission for trellis toppers, wind damage prevention, hit-and-miss for exposed sites