Drainage

16 articles

• Blocked Drains: Diagnosis, Rodding, Jetting & When to Call a Specialist
  Blocked drain diagnosis: rodding, high-pressure jetting, CCTV survey, root intrusion; responsibility boundaries
• Drain CCTV Survey: MSCC4 Defect Grading, What to Look For, Report Format and When to Commission
  MSCC4 defect grading A/B/C codes, survey reporting format, when to commission (purchase, blockage, subsidence), report interpretation for repair decisions
• Drainage Near Trees: BRE Digest 298 Safe Distances, Shrinkable Clay Risk, Flexible Joints and Building Control Guidance
  BRE Digest 298 species/height safe distances, shrinkable clay (NHBC Chapter 4.2) risk zones, flexible joints every 600mm, Building Control notification requirements
• Foul Drainage Design: Above-Ground Stack Sizing, Branch Discharge Units, Ventilation and Approved Document H
  Above-ground stack sizing using discharge unit method, branch gradient 18–90mm, ventilation via primary stack or AAV, Approved Document H table requirements
• Inspection Chamber & Manhole Construction: Depths, Materials & Access Requirements
  Inspection chambers and manholes: precast concrete, plastic chambers, cover grades, benching requirements, Part H compliance
• No-Dig Drain Repair: Patch Lining, CIPP Full Relining, Resin Injection and Lateral Relining Methods
  Patch lining for local defects, CIPP full relining for long runs, resin injection for joint repair, lateral relining — access, cost, and material selection
• Petrol and Oil Interceptors: BS EN 858 Class I/II Selection, Bypass Volume, Maintenance and Environment Agency Requirements
  BS EN 858 Class I (≤5mg/l) vs Class II (≤100mg/l) selection, bypass volume calculation, 6-monthly maintenance, EA discharge consent requirements
• Rainwater Harvesting Systems: Regulations, Tank Sizing & Installation
  Rainwater harvesting: non-potable use, tank sizing (CIRIA C539), first-flush diverters, Water Regulations backflow prevention
• Root Intrusion in Drains: High-Risk Species, CCTV Identification, High-Pressure Jetting vs Root Cutting and Relining
  High-risk species (willows, poplars, ash), CCTV identification codes, high-pressure jetting (40 bar) vs mechanical root cutting vs relining as permanent fix
• Septic Tanks and Cesspools: 2020 General Binding Rules, BS EN 12566 and Environment Agency Registration
  Septic tanks and cesspools: 2020 General Binding Rules, direct watercourse discharge now non-compliant, BS EN 12566, drainage field design and percolation testing, EA registration
• Soakaway Design & Installation: BRE Digest 365 Calculations
  Soakaway design: BRE Digest 365 percolation test method, crate vs rubble fill, minimum 5m from buildings
• Soakaway Sizing and Design: BRE Digest 365, Percolation Testing and Part H
  BRE Digest 365 percolation testing (3 pits × 3 tests), infiltration rate f calculation, S = (A_d × i × D) - (a_s × f × D) sizing equation, worked example for 75m² roof on sandy clay, 5m min from building, 2.5m from boundary, 24h drain target, granular vs crate construction
• SuDS Design for Small Sites: CIRIA C753, Attenuation Calculations, Infiltration Testing and Approval Process
  SuDS design for small sites: CIRIA C753, greenfield runoff rates, BRE 365 infiltration testing, attenuation volume calculation, SAB approval process in Wales
• Underground Drainage: Pipe Sizes, Gradients & Building Regs Part H
  Underground drainage: 100mm/150mm pipe sizes, 1:40 gradient for 100mm, Approved Document H requirements, inspection access
• When Is a Grease Trap Required and How Do They Work?
  FOG requirement for commercial kitchens, BS EN 1825 sizing, Part H, trade effluent consent, passive vs AGRU (automatic grease removal unit) comparison
• When Is a Sewage Pumping Station Required and How Is It Sized and Maintained?
  When pumped drainage is needed, BS EN 12050 standards, wet well sizing, Sewers for Adoption 7th Edition, Section 104 adoption, alarm requirements