Plasterboard Partition Walls in London Home Renovation: Types, Specification, and Installation

THE CHOICE BETWEEN STEEL STUD (METAL FRAME) AND TIMBER STUD PARTITIONS IS DRIVEN BY: FIRE REQUIREMENTS; ACOUSTIC REQUIREMENTS; MOISTURE EXPOSURE; STRUCTURAL LOADING ON THE WALL; AND TRADE PREFERENCE.

STEEL STUD (METAL FRAME) PARTITION: THE DOMINANT SYSTEM IN COMMERCIAL AND INCREASINGLY RESIDENTIAL RENOVATION. COMPONENTS: GALVANISED STEEL FLOOR AND CEILING TRACK (45MM, 70MM, 92MM, 146MM TRACK WIDTH); GALVANISED STEEL C-STUDS AT 400MM OR 600MM CENTRES; ACOUSTIC MINERAL WOOL INFILL; PLASTERBOARD BOTH FACES. ADVANTAGES: FASTER INSTALLATION THAN TIMBER; DIMENSIONALLY STABLE (DOES NOT SHRINK, WARP, OR SWELL); THINNER THAN EQUIVALENT ACOUSTIC TIMBER PARTITION; COMPATIBLE WITH GYPSUM DRYWALL SCREWS DIRECT TO STUD WITHOUT PRE-DRILLING; FIRE PERFORMANCE WELL-DOCUMENTED AND TEST-EVIDENCED (BRITISH GYPSUM, KNAUF, SINIAT TEST DATA); NO SHRINKAGE CRACKING. DISADVANTAGES: CANNOT CARRY HEAVY WALL LOADS (HEAVY SHELVING, WALL-HUNG SANITARYWARE) WITHOUT NOGGINGS OR SPECIALIST FIXINGS — SEE BELOW.

TIMBER STUD PARTITION: STILL WIDELY USED IN UK RESIDENTIAL RENOVATION — PARTICULARLY WHERE TRADES ARE FAMILIAR WITH TIMBER AND FOR REFURBISHMENT OF EXISTING TIMBER-FRAMED AREAS. COMPONENTS: C16 OR C24 GRADED SOFTWOOD (TYPICALLY 75X50MM OR 100X50MM); SOLE AND HEAD PLATES; NOGGINS AT MID-HEIGHT; PLASTERBOARD BOTH FACES. ADVANTAGES: EASY TO FIX HEAVY LOADS TO (THROUGH-BOLT, WOOD SCREWS INTO STUD/NOGGIN); FAMILIAR SYSTEM FOR MOST TRADES; LOWER MATERIAL COST IN SIMPLE APPLICATIONS. DISADVANTAGES: TIMBER SHRINKAGE CAN CAUSE CRACKING AT JOINTS; HEAVIER AND THICKER THAN METAL STUD EQUIVALENT; SUSCEPTIBLE TO MOISTURE IN WET AREAS UNLESS TREATED TIMBER IS USED.

FIXING LOADS TO PARTITIONS: BOTH STEEL AND TIMBER PARTITIONS REQUIRE ADEQUATE FIXING POINTS FOR HEAVY WALL LOADS: - HEAVY SHELVING OR KITCHEN WALL UNITS: FIX INTO STUDS DIRECTLY (TIMBER) OR INSTALL 18MM OSB/PLYWOOD NOGGING BETWEEN STUDS (METAL FRAME) — SCREW THROUGH BOARD INTO PLY - WALL-HUNG SANITARYWARE (WALL-HUNG WC: TYPICALLY 200KG DYNAMIC LOAD): INSTALL STUDDED CARRIER FRAME (GROHE RAPID SL, GEBERIT DUOFIX BASIC) OR REINFORCE PARTITION WITH 18MM PLYWOOD SPANNING 2+ STUDS - TV WALL MOUNTS: MOUNT TO STUDS DIRECTLY OR INSTALL PLY BACKING — NEVER TO PLASTERBOARD ALONE WITH HOLLOW-WALL FIXINGS FOR HEAVY SCREENS

PLASTERBOARD IS NOT A SINGLE PRODUCT — DIFFERENT BOARD TYPES SERVE DIFFERENT PERFORMANCE REQUIREMENTS. USING THE WRONG BOARD TYPE IN THE WRONG LOCATION IS A COMMON AND COSTLY MISTAKE.

STANDARD (WHITE) PLASTERBOARD: BRITISH GYPSUM GYPROC WALLBOARD, KNAUF DRYWALL STANDARD, OR SINIAT STANDARD BOARD — AVAILABLE IN 9.5MM AND 12.5MM THICKNESS. USED FOR: STANDARD ROOM PARTITIONS; GENERAL WALL LININGS; CEILINGS IN DRY AREAS. 12.5MM IS THE PREFERRED THICKNESS FOR WALL PARTITIONS IN MOST UK RESIDENTIAL WORK.

MOISTURE-RESISTANT (GREEN) BOARD: BRITISH GYPSUM GYPROC MOISTURE BOARD (GREEN FACE), KNAUF AQUAPANEL INDOOR (CEMENT BOARD), OR SINIAT HYDRO. USED FOR: WET ROOM AND BATHROOM PARTITIONS WHERE CERAMIC TILES WILL BE APPLIED; KITCHEN WALL BACKGROUNDS WHERE COOKING SPLATTER AND STEAM ARE PRESENT; ANYWHERE WITH ELEVATED AMBIENT HUMIDITY. GYPROC MOISTURE BOARD IS NOT WATERPROOF — IT IS MOISTURE-RESISTANT AND DESIGNED AS A TILE SUBSTRATE. FOR FULL WET AREAS (SHOWER ENCLOSURES, WET ROOMS WHERE WATER RUNS DOWN THE WALL): USE WEDI BOARD (RIGID FOAM + GLASS FIBRE MESH) OR HARDIE BACKER CEMENT BOARD (9MM), WHICH ARE FULLY WATERPROOF SUBSTRATES, WITH A SEPARATE LIQUID APPLIED TANKING (MAPEI MAPELASTIC SMART OR ARDEX 8+9) AT JUNCTIONS AND CHANGES OF PLANE.

FIRE-RATED (PINK) BOARD: BRITISH GYPSUM GYPROC FIRELINE (FIRELINE FC OR FIRELINE BM) — 12.5MM OR 15MM; KNAUF FIREBOARD; SINIAT FRAMECAL F. USED FOR: FIRE-RATED PARTITIONS IN LOFT CONVERSIONS (ESCAPE ROUTE FIRE DOORS AND PARTITIONS — MINIMUM 30 MINUTE FIRE RESISTANCE, FD30); GARAGE-TO-HOUSE PARTITIONS (REQUIRE 30 MIN MINIMUM FIRE RESISTANCE UNDER BUILDING REGULATIONS PART B); PROTECTED CORRIDORS IN HMO OR APARTMENTS. OFTEN TWO LAYERS OF 12.5MM FIRELINE ARE USED TO ACHIEVE 60 MINUTE RESISTANCE (EI60).

HIGH-DENSITY ACOUSTIC BOARD: BRITISH GYPSUM GYPROC SOUNDBLOC (13MM HIGH-DENSITY); KNAUF SAFEBOARD (ANTI-BANGING BOARD); OR STANDARD BOARD WITH ACOUSTIC INTERLAYER. USED TO INCREASE MASS OF A PARTITION AND THEREFORE IMPROVE AIRBORNE SOUND INSULATION. A DOUBLE-LAYER SYSTEM (TWO 12.5MM SOUNDBLOC BOARDS EACH FACE OF A METAL STUD PARTITION WITH 100MM ACOUSTIC MINERAL WOOL AND STAGGERED JOINTS) CAN ACHIEVE RW 55-60 DB — ADEQUATE FOR MOST RESIDENTIAL PARTY WALL OR BEDROOM-TO-LIVING ROOM SITUATIONS.

ACOUSTIC PERFORMANCE IS A SIGNIFICANT DRIVER IN LONDON HOME RENOVATION — PARTICULARLY FOR: BEDROOMS ADJACENT TO LIVING ROOMS OR KITCHENS; LOFT CONVERSION ROOMS; HOME OFFICE SPACES; AND SEPARATING NEW UTILITY ROOMS OR BATHROOMS FROM ADJACENT BEDROOMS.

RELEVANT STANDARDS: BUILDING REGULATIONS PART E SPECIFIES ACOUSTIC REQUIREMENTS FOR SEPARATING WALLS AND FLOORS BETWEEN DWELLINGS (E.G. TERRACE-TO-TERRACE PARTY WALLS — MINIMUM 45 DB DnTw). INTERNAL PARTITIONS (WITHIN A SINGLE DWELLING) ARE NOT SUBJECT TO MANDATORY PART E REQUIREMENTS — BUT GOOD DESIGN SHOULD ACHIEVE: BEDROOM PARTITIONS AT MINIMUM RW 40 DB; HOME OFFICE PARTITIONS AT RW 45-50 DB.

STANDARD METAL STUD PARTITION — TYPICAL ACOUSTIC PERFORMANCE: - 70MM METAL STUD, SINGLE LAYER 12.5MM STD BOARD EACH FACE, NO INSULATION: ~RW 36 DB - 70MM METAL STUD, SINGLE LAYER 12.5MM STD BOARD EACH FACE, 50MM MINERAL WOOL: ~RW 42 DB - 70MM METAL STUD, SINGLE LAYER 12.5MM SOUNDBLOC EACH FACE, 70MM MINERAL WOOL: ~RW 47 DB - 70MM METAL STUD, DOUBLE LAYER 12.5MM SOUNDBLOC EACH FACE, 100MM ACOUSTIC MINERAL WOOL (KNAUF EARTHWOOL ACOUSTIC PARTITION ROLL): ~RW 55 DB

ACOUSTIC MINERAL WOOL OPTIONS: KNAUF EARTHWOOL ACOUSTIC PARTITION ROLL (32KG/M³); ROCKWOOL ROCKFALL (30KG/M³); ISOVER ULTIMATE PARTY WALL ROLL (32KG/M³). ALL ARE SUITABLE FOR PARTITION INFILL — HIGHER DENSITY GIVES MARGINALLY BETTER ACOUSTIC PERFORMANCE BUT THE MINERAL WOOL TYPE IS LESS IMPORTANT THAN THE OVERALL SYSTEM SPECIFICATION.

ACOUSTIC RESILIENT BARS: BRITISH GYPSUM GENIE CLIP LB OR KNAUF ACOUSTIC RESILIENT BAR — ISOLATE THE PLASTERBOARD FACING FROM THE STUD TO REDUCE STRUCTURE-BORNE SOUND TRANSMISSION. ADD 3-5 DB PERFORMANCE IMPROVEMENT OVER STANDARD DIRECT-FIX. RECOMMENDED FOR BEDROOM WALLS ADJACENT TO PLANT ROOMS, UTILITY ROOMS, OR LIVING AREAS.

ACOUSTIC PUTTY PADS FOR ELECTRICAL SOCKETS: EVERY ELECTRICAL BACK BOX IN A PARTITION BREAKS THE ACOUSTIC SEAL — BACK BOXES BACK-TO-BACK ARE ESPECIALLY PROBLEMATIC. USE ACOUSTIC PUTTY PADS (BRITISH GYPSUM GYPROC ACOUSTIC SEALANT, ROCKWOOL FLEXI PAD) BEHIND BACK BOXES, OR STAGGER SOCKET POSITIONS ON OPPOSITE FACES OF THE WALL.

INTERNAL PARTITION COSTS VARY SIGNIFICANTLY WITH: SPECIFICATION; AREA; NUMBER OF DOOR OPENINGS; REQUIREMENT FOR ACOUSTIC OR FIRE PERFORMANCE; AND ACCESS/FLOOR AREA TO WORK IN.

TYPICAL LONDON MARKET COSTS (SUPPLY AND INSTALL): STANDARD METAL STUD PARTITION (70MM STUD, SINGLE 12.5MM STD BOARD EACH FACE, NO INSULATION, TAPED AND JOINTED READY FOR DECORATION): - MATERIAL COST: APPROXIMATELY £12-18/M² OF WALL FACE AREA - LABOUR: APPROXIMATELY £15-25/M² OF WALL FACE AREA - TOTAL: £27-43/M²

STANDARD ACOUSTIC PARTITION (70MM STUD, SINGLE SOUNDBLOC EACH FACE, 70MM MINERAL WOOL): - TOTAL: £35-55/M²

HIGH-PERFORMANCE ACOUSTIC PARTITION (DOUBLE SOUNDBLOC EACH FACE, RESILIENT BARS, MINERAL WOOL): - TOTAL: £55-80/M²

FIRE-RATED PARTITION (DOUBLE 12.5MM FIRELINE EACH FACE, METAL STUD, TO ACHIEVE EI60): - TOTAL: £50-75/M²

BATHROOM WET ROOM PARTITION (WEDI BOARD OR HARDIE BACKER, TANKED, TILED): - WEDI BOARD SUPPLY AND FIT: £35-55/M² BEFORE TILING - TILING AND ADHESIVE/GROUT: £40-90/M² ADDITIONAL

DOOR OPENING (ALLOW AS PART OF PARTITION QUOTE): - METAL STUD HEAD BRACE AND DOOR FRAME PREPARATION: £150-300 PER OPENING - INTERNAL DOOR (SUPPLY AND HANG): £200-600 (SHAKER SOLID CORE MID-RANGE LPD DOORS OR XL JOINERY) - FD30S FIRE DOOR (SUPPLY AND HANG WITH FRAME, INTUMESCENT SEALS, CLOSER): £400-900