basement-waterproofing

15 articles

• Basement Conversion Building Regs: Parts A, B, C, F and Structural Engineer Involvement
  Basement conversion Building Regulations: Parts A (structure/underpinning), B (fire escape/protected staircase), C (moisture/BS 8102), F (MVHR ventilation), L (0.18 W/m²K floor), Full Plans route, CDM 2015, Party Wall Act 1996 notice requirements
• Basement Floor Waterproofing: Bonded Sheet Membrane, Liquid-Applied Systems and Screed Specification
  Basement floor waterproofing: bonded sheet membrane (bituminous/HDPE), liquid-applied PU/epoxy (seamless), crystalline (self-seals to 0.4mm), cementitious slurry, 45° cant fillet at floor-wall junction (mandatory), screed minimums (50mm bonded, 65mm floating), substrate moisture threshold (75% RH)
• Basement Retaining Wall Design: Temporary Works, Lateral Earth Pressure, Waterproofing and Drainage
  Basement retaining wall design: lateral earth pressure (Ka ≈ 0.33 at φ=30°), RC wall thickness (200–300mm), C32/40 concrete, construction joint waterstop specification, temporary works systems (sheet piling, king post walls), CDM Regulations 2015 checking requirements
• Basement Ventilation Requirements: Part F, Humidity Control, Mechanical Ventilation Options and Condensation Risk
  Basement ventilation: Approved Document F 2021 rates (8 l/s continuous, 15 l/s intermittent), why natural ventilation fails below ground, MVHR as recommended solution, MEV alternative, humidity targets (40–60% RH), condensation risk at wall-floor thermal bridge junction, CO risk from basement appliances
• Basement Wall Waterproofing: Cementitious Coatings, Crystalline Systems and Render-Based Approaches
  Basement wall waterproofing: cementitious slurry (2-coat, 3mm DFT), crystalline systems (concrete only, 0.4mm self-sealing), render-based (1:3 mix, 15mm minimum), bentonite panels (external/new build only), negative vs positive face application, substrate preparation by material type, common failure modes
• Basement Waterproofing Failure Diagnosis: Active Leaks vs Condensation, Crack Injection and Remedial System Options
  Basement waterproofing failure diagnosis: condensation vs active ingress (salt analysis, moisture meter, thermal imaging), fault-finding decision tree, PU foam vs epoxy crack injection, Type C cavity drain vs negative face tanking for remediation, CCTV drain survey importance
• BS 8102 Type A, B and C Waterproofing: Barrier, Structurally Integral and Drained Cavity — When to Use Each
  BS 8102:2022 Type A/B/C waterproofing: Type A (barrier tanking), Type B (structurally integral waterproof concrete), Type C (cavity drain + sump), Grade 1–4 usage grades, multi-system combinations for Grade 3 habitable use, when each type is appropriate
• BS 8102 Warranty Requirements: What Guarantees Cover, Insurance-Backed Warranties and Specifier Responsibilities
  BS 8102 warranty requirements: BWPDA and PCA insurance-backed guarantees (IBGs), what they cover vs exclude (flooding/pump failure excluded), CSSW specifier role, manufacturer approved applicator warranties, sump pump maintenance obligations for IBG validity
• BWPDA and PCA Membership: Why Clients Should Use Registered Contractors and What Guarantees Cover
  BWPDA/PCA membership: what insurance-backed guarantees (IBGs) cover vs exclude (workmanship yes, flooding/subsidence no), CIGA 30-year guarantees for chemical DPC, how to verify membership online, conveyancing implications, dispute resolution through trade body
• Cavity Drain Membrane Systems: Floor and Wall Membrane, Studded Profile, Sump Pump Sizing and Drainage Channel
  Cavity drain membrane systems: how Type C works, HDPE studded profiles (8mm wall/20mm floor), Newton Basedrain drainage channel, sump pump sizing (30–60 l/min), duty/standby dual pump configuration, battery backup, quarterly/annual maintenance, costs £100–£200/m²
• External Tanking Systems: Cementitious Slurry, Sheet Membranes, Drainage Board and Drainage Layer Details
  External tanking systems: cementitious slurry (3mm min DFT, 2-coat), torch-on/self-adhesive bituminous sheet (100mm laps), cold-applied liquid rubber, drainage board protecting membrane from backfill, 150mm granular layer and perimeter drain, BS 8102 Type A classification
• Groundwater Risk Assessment for Basements: Ground Investigation, Hydrostatic Pressure and Design Water Table
  Groundwater risk assessment for basements: Phase 1 desk study, standpipe monitoring (6-month minimum), WC1/WC2/WC3 classification under BS 8102:2022, hydrostatic pressure calculation (10 kPa per metre head), bore investigation methods, and IBG documentation requirements
• Structural Waterproofing Design: BS 8102 Grade 1–4 Usage Grades, Specifying the Right System for the Conversion
  Structural waterproofing design: BS 8102:2022 Grades 1–4 with real-world examples, water condition classifications WC1–WC3, SWD (Structural Waterproofing Designer) and CSSW qualification, ground investigation requirements, 25-year minimum design life, multi-layer system specification
• Sump Pump Selection: Submersible vs Pedestal, Single vs Dual Pump, Capacity Calculation and Battery Backup
  Sump pump selection: submersible vs pedestal types, sizing (30–60 l/min domestic, 3–5× safety margin), sump pit spec (300mm min diameter, 600mm deep), float switch types, duty/standby configuration per BS 8102:2022, battery backup, discharge check valve and 32mm minimum bore
• Waterproofing Existing Basements: Survey Process, Identifying Failure Points and System Selection Based on Access
  Waterproofing existing basements: survey process (dampness mapping, moisture meter grid, salt analysis), identifying failure types, access constraints limiting choices to Type A or C, system selection matrix, PU foam for active leaks vs epoxy for structural crack repair