Damp & Waterproofing

27 articles

• Balcony Waterproofing: EPDM, Liquid Applied Systems, Falls, BS 6229 and Drainage Detail
  Like a small flat roof; 1:80 finished/1:40 design fall; door threshold drainage channel resolves Part M vs upstand conflict; 150mm upstands; Part K guarding 1100mm/100mm sphere; balustrade fixings through membrane; thermal break
• Basement Tanking: Membrane Systems, Cementitious Coatings & Cavity Drain
  Basement tanking: Type A (barrier), Type B (structural), Type C (cavity drain); BS 8102:2022 waterproofing grades
• Basement Waterproofing Systems
  BS 8102:2022: Type A barrier tanking, Type B structurally integral concrete, Type C drained cavity membrane + sump/pump; combine 2+ types for habitable; specialist design
• Breathable Lime Render for Older Properties
  Lime render for pre-1919 solid walls; NHL 2/3.5/5 per BS EN 459-1; 1:2.5-1:3 with sharp sand; three coats (scratch/float/finish); vapour-permeable, prevents trapped damp
• Cavity Wall Tie Failure
  Cavity wall tie failure: mild steel ties (1920s-80s) corrode and expand; horizontal cracks at ~450mm centres; structural + damp bridge risk; borescope diagnosis; remedial ties
• Chimney Damp: Rain Penetration, Condensation & Salt Staining Diagnosis
  Chimney damp: distinguishing rain penetration, unused flue condensation, and hygroscopic salt contamination
• Condensation Problems: Causes, Mould Prevention & Ventilation Solutions
  Condensation and mould: dew point, cold bridges, ventilation solutions (PIV, MVHR), thermal imaging diagnosis
• Condensation vs Leak vs Penetrating Damp: How to Diagnose the Source of Moisture
  70-80% UK damp complaints are condensation, <5% true rising damp; diagnostic framework — surface temp vs dew point, salt test for rising, external inspection for penetrating; BS 5250:2021, BS 6576:2005+A1:2012; Awaab's Law / Homes (Fitness for Human Habitation) Act 2018 landlord duty; tools £100 covers 80% of surveys
• Damp Proof Course Replacement: Chemical Injection, Physical DPC & When You Need It
  DPC replacement: chemical injection (silane/siloxane), electro-osmotic systems, physical DPC insertion, lime replastering
• How Do You Diagnose Salt Damp and Cryptofluorescence in Old Buildings?
  Hygroscopic salt mechanisms, chloride/nitrate/sulphate identification, moisture meter limitations with salts, poultice treatment, sacrificial plaster approach for heritage buildings
• How Do You Survey a Damp Property? Damp Meter Readings, Diagnosis and Scope of Works
  Damp surveying: moisture meter readings at multiple heights (>17% timber or >1,000 relative units = elevated), rising vs penetrating vs condensation diagnosis, source identification before scoping remediation
• How Is a Cavity Drainage Membrane System Installed?
  Cavity drain membrane installation (Newton 508, Platon, Oldroyd), floor-to-wall sequence, sump pump design, perimeter drainage channel, pressure ratings and guarantees
• How Is Wet Rot and Dry Rot Diagnosed and Treated?
  Serpula lacrymans (dry rot) vs Coniophora puteana (wet rot) identification, 600mm removal margin for dry rot, boron treatment, epoxy consolidant repairs, BS 8417
• Internal Wall Insulation and Damp Risk
  IWI damp risk: makes wall colder/wetter, reduces inward drying, interstitial condensation; fix damp first; vapour control system-specific; cold bridge junctions; ventilation; PAS 2035
• Mould Remediation: Kill, Remove, Prevent — Products & Ventilation Solutions
  Mould remediation: identify cause, kill with biocide, remove, prevent with ventilation and PIV — Awaab's Law obligations
• Mould Treatment and Prevention
  Mould = excess moisture symptom; fungicidal wash + fix the source (Part F ventilation, Part L cold-bridge insulation); Awaab's Law / HHSRS landlord duties
• Parapet Wall Damp: Lead Flashing Failures, DPC Junctions, EPDM Capping and Common Fault Diagnosis
  Coping joints/DPC + lead flashing + cavity tray failures; inspect coping FIRST (water tracks down); worse-after-rain high-on-wall = penetrating; LSTA lead piece-length limits; EPDM alternatives; BS 6229 150mm upstand
• Penetrating Damp Investigation: Causes, Diagnosis and Remediation
  Penetrating damp diagnosis: external defect identification first, moisture meter mapping, calcium carbide and gravimetric sample testing, PCA CoP, BS 5250:2021; remediation hierarchy (source → dry → finish); 25–30mm/month drying rates; salt management with renovation render
• Rising Damp vs Penetrating Damp
  Rising damp (upward, <1-1.5m, tide mark, DPC failure/bridge) vs penetrating damp (inward, any height, external defect); diagnose by elimination; meters read salts; rule out condensation
• Rising Damp vs Penetrating Damp: How to Tell the Difference & Fix Each
  Rising vs penetrating damp diagnosis: salt tide marks, hygroscopic salts, chemical DPC injection, cement render replacement
• Warm Roof vs Cold Roof: Which Flat Roof Construction to Specify and Why
• What Are the Requirements for Damp-Proof Membranes in Floors and Walls?
  DPC vs DPM distinction, 1200 gauge polythene minimum, Approved Document C requirements, 150mm upstand, linking to wall DPC, radon membrane overlap
• What Are the Waterproofing Options for Basements and Below-Ground Structures?
  BS 8102:2022 Type A/B/C waterproofing systems, Grade 1–4 usage grades, cavity drain membranes, sump and pump sizing, CSSW qualification requirements
• What Causes Damp in Flat Roofs and How Is It Fixed?
  Flat roof damp sources: minimum falls (1:80), felt failure modes (blistering, cracking), EPDM vs GRP vs liquid systems, thermal imaging for wet decks, BS 6229
• What Causes Penetrating Damp and How Is It Diagnosed and Treated?
  Penetrating damp sources (pointing, flashings, flat roofs), diagnosis methods (moisture meter, thermal imaging, salt testing), remedies by source, distinguishing from rising damp
• What Is Interstitial Condensation and How Is It Prevented?
  Glaser method, BS EN ISO 13788, vapour control layer positioning, flat roof and IWI condensation risk scenarios, WUFI dynamic hygrothermal calculation
• When and Where Should Breathable Membranes Be Used in Construction?
  Vapour permeable vs vapour barrier, Sd values, pitched roof and timber frame membrane use per BS 4016, fixing and lapping, condensation risk per BS EN ISO 13788