Staircase Renovation for London Victorian Homes: Balustrade, Handrail, and Building Regs Guide

A TYPICAL GROUND-TO-FIRST-FLOOR STAIRCASE IN A LONDON VICTORIAN TERRACE CONSISTS OF THE FOLLOWING STRUCTURAL AND ARCHITECTURAL COMPONENTS. THE CARRIAGE (OR STRUCTURAL STRING): IN OLDER PROPERTIES, THE STAIR IS SUPPORTED ON A CENTRAL TIMBER CARRIAGE BEAM (TYPICALLY 75X200MM SOFTWOOD), WITH THE TREADS BEARING ONTO IT. IN LATER VICTORIAN CONSTRUCTION, THE STAIR IS A CUT AND BRACKETED STRING CONSTRUCTION WITH OPEN STRINGS (WHERE THE TREAD NOSINGS ARE VISIBLE FROM THE SIDE) OR A CLOSED STRING (WHERE A CONTINUOUS TIMBER STRING BOARD CONCEALS THE TREAD AND RISER ENDS).

THE TREADS (HORIZONTAL SURFACES) ARE TYPICALLY 25MM SOFTWOOD (PINUS SYLVESTRIS — EUROPEAN REDWOOD OR SCOTS PINE). THE RISERS (VERTICAL SURFACES BETWEEN TREADS) ARE 19MM SOFTWOOD. THE NEWEL POSTS (LARGE CORNER POSTS AT THE BOTTOM, LANDING, AND TOP OF THE STAIR) ARE 100X100MM OR 90X90MM SOFTWOOD. THE HANDRAIL IS A CONTINUOUS PROFILED TIMBER RAIL ON BRACKETS, TYPICALLY TUDOR OR MOPSTICK PROFILE. THE BALUSTERS (SPINDLES) ARE 41X41MM SQUARE SOFTWOOD AT 100MM CENTRES.

COMMON DEFECTS IN UNRESTORED VICTORIAN STAIRCASES: CREAKING TREADS DUE TO LOOSE WEDGES OR DRIED GLUE AT TREAD-AND-RISER JOINTS. LOOSE BALUSTRADE DUE TO FAILED BALUSTERS OR LOOSE HANDRAIL BRACKETS. ROTTEN NEWEL POST BASE WHERE IT MEETS THE GROUND FLOOR SUBSTRATE (PARTICULARLY WHERE THE POST IS PLANTED DIRECTLY ON A DAMP SOLID FLOOR WITHOUT DAMP BREAK). WIDE BALUSTER GAPS (ORIGINAL VICTORIAN STAIRCASES OFTEN HAVE 120MM+ GAPS BETWEEN BALUSTERS — NON-COMPLIANT WITH CURRENT PART K WHICH REQUIRES 100MM MAXIMUM).

BUILDING REGULATIONS APPROVED DOCUMENT K (PROTECTION FROM FALLING, COLLISION, AND IMPACT) SETS OUT THE MANDATORY REQUIREMENTS FOR STAIRCASE GUARDING (BALUSTRADE AND HANDRAIL) IN DWELLINGS.

KEY PART K REQUIREMENTS FOR DOMESTIC STAIRCASES: MINIMUM GUARDING HEIGHT: 900MM MEASURED FROM THE PITCH LINE OF THE STAIR (THE SLOPING LINE CONNECTING THE FRONT EDGE OF EACH TREAD NOSING) FOR STAIRS WITHIN A PRIVATE DWELLING. WHERE THE STAIR SERVES AN AREA WITH A DROP GREATER THAN 600MM (E.G., AN OPEN-PLAN MEZZANINE OR A FIRST-FLOOR LANDING OVERLOOKING A DOUBLE-HEIGHT SPACE), THE MINIMUM GUARDING HEIGHT IS 1100MM FOR ANY BALUSTRADE OR RAILING PROTECTING FROM A DROP. NOTE: WHERE GUARDING IS BEING REPLACED OR ALTERED, THE NEW GUARDING MUST MEET THE CURRENT 900MM MINIMUM — IT CANNOT BE LOWER EVEN IF THE ORIGINAL WAS.

100MM SPHERE TEST: NO OPENING IN THE BALUSTRADE (BETWEEN BALUSTERS, BETWEEN GLASS PANELS, OR IN ANY OTHER CONFIGURATION) SHOULD ALLOW A 100MM DIAMETER SPHERE TO PASS THROUGH. THIS PREVENTS CHILDREN'S HEADS BECOMING TRAPPED. IN PRACTICE, BALUSTER CENTRES SHOULD BE MAXIMUM 99MM TO PASS THE 100MM SPHERE TEST WITH SQUARE OR ROUND SPINDLES.

HANDRAIL HEIGHT: BETWEEN 900MM AND 1000MM ABOVE THE PITCH LINE ON A STAIR OR ABOVE THE FLOOR ON A LANDING. THE HANDRAIL MUST BE CONTINUOUS THROUGHOUT THE LENGTH OF THE STAIR.

OPEN RISERS: PERMITTED ON DOMESTIC STAIRS SUBJECT TO A SEPARATE TEST — THE OPENING BETWEEN TREADS MUST NOT ALLOW A 100MM SPHERE TO PASS THROUGH HORIZONTALLY. THIS EFFECTIVELY LIMITS THE RISE-TO-GOING GEOMETRY OF OPEN-RISER STAIRS. WHERE OPEN RISERS ARE SPECIFIED FOR AESTHETIC REASONS, THE STRUCTURAL ENGINEER OR DESIGNER MUST CONFIRM THE GEOMETRY PASSES THE 100MM TEST IN THE PLAN SECTION.

STRUCTURAL GLASS BALUSTRADE IS THE MOST POPULAR CONTEMPORARY STAIRCASE UPGRADE IN LONDON RESIDENTIAL PROJECTS AND DRAMATICALLY INCREASES THE LIGHT TRANSMISSION THROUGH A STAIRCASE HALL.

THE TWO MAIN GLASS BALUSTRADE CONFIGURATIONS ARE CHANNEL-BASE (FRAMELESS) AND POST-MOUNTED (SEMI-FRAMELESS). CHANNEL-BASE (FRAMELESS) GLASS BALUSTRADE: 17.5MM LAMINATED TOUGHENED SAFETY GLASS PANELS (TWO LAYERS OF 8MM TOUGHENED GLASS BONDED WITH CLEAR INTERLAYER — TYPICALLY GUARDIAN CLIMACOOL, PILKINGTON OPTIFLOAT, OR EQUIVALENT BS 6206 CLASS A COMPLIANT GLASS) SET INTO A BASE CHANNEL OF STAINLESS STEEL OR ALUMINIUM FIXED TO THE STAIR STRUCTURE. THE GLASS PANEL ITSELF FORMS THE GUARD — THERE IS NO POST OR INTERMEDIATE RAIL. THE HANDRAIL (CIMASA STRUCTURAL GLASS HANDRAIL RAIL OR A TIMBER CAP RAIL) IS BONDED OR CLAMPED TO THE TOP EDGE OF THE GLASS PANEL. CHANNEL SYSTEMS REQUIRE THE GLASS TO CARRY ALL LATERAL LOADS AND MUST BE ENGINEERED — A STRUCTURAL CALCULATION CONFIRMING THE GLASS PANEL THICKNESS, PANEL WIDTH, AND BASE CHANNEL FIXINGS CAN RESIST THE HORIZONTAL LOAD (MINIMUM 0.74 KN/M AT THE TOP OF THE GUARD FOR DOMESTIC STAIRS) IS REQUIRED FOR BUILDING CONTROL.

POST-MOUNTED GLASS BALUSTRADE: STAINLESS STEEL 316-GRADE POSTS AT MAXIMUM 1500MM CENTRES CARRY THE LOAD, WITH GLASS INFILL PANELS CLAMPED BETWEEN THE POSTS. POSTS CAN BE SIDE-FIXED TO THE STAIR STRUCTURE (NEATER FOR OPEN-STRING STAIRS) OR CORE-DRILLED INTO CONCRETE LANDINGS. COMMON POST SYSTEMS: Q-RAILING EASY GLASS MINI (SURFACE-MOUNTED ALUMINIUM BASE SHOE PROFILE, FRAMELESS APPEARANCE WITH SMALL SHOE); BALCO GLASS RAILING; AND VIVA FRAMELESS GLASS.

GLASS SPECIFICATIONS FOR BALUSTRADE: ALL GLASS IN BALUSTRADE APPLICATIONS MUST BE LAMINATED SAFETY GLASS TO BS EN 12543-1 OR TOUGHENED SAFETY GLASS TO BS EN 12150. TOUGHENED-ONLY GLASS (SINGLE-PANE TOUGHENED) IS NOT RECOMMENDED FOR BALUSTRADE — IF IT FAILS, IT SHATTERS COMPLETELY AND THE GUARD IS INSTANTLY ABSENT. LAMINATED TOUGHENED GLASS (LTG) IS THE PREFERRED SPECIFICATION — ON FAILURE, THE INTERLAYER HOLDS THE BROKEN GLASS IN PLACE.

WHERE A CONTEMPORARY GLASS BALUSTRADE IS NOT WANTED, TIMBER OR STEEL ALTERNATIVES OFFER GOOD DESIGN OPTIONS.

TIMBER BALUSTRADES: THE STANDARD REPLACEMENT TIMBER BALUSTRADE FOR A VICTORIAN TERRACE USES TURNED OAK BALUSTERS (41X41MM SQUARE OR 35MM ROUND, TURNED IN TRADITIONAL BARLEY TWIST OR CONTEMPORARY SQUARE PROFILE) AT MAXIMUM 99MM CENTRES. NEWEL POSTS IN SOLID OAK (90X90MM OR 100X100MM) WITH CHAMFERED CAPITALS GIVE A TRADITIONAL-CONTEMPORARY BALANCE. HANDRAILS IN SOLID OAK MOPSTICK (ROUND) OR GROOVED D-RAIL PROFILE AT 900MM TO 1000MM HEIGHT. RICHARD BURBIDGE TRADEMARK OAK COLLECTION AND CHESHIRE MOULDINGS CONTEMPORARY OAK SPINDLE RANGES ARE THE MAIN TRADE SUPPLIERS FOR TIMBER BALUSTRADE COMPONENTS THROUGH JEWSON, TRAVIS PERKINS, AND SPECIALIST JOINERY MERCHANTS.

STEEL CABLE BALUSTRADE: HORIZONTAL STAINLESS STEEL CABLES (TYPICALLY 4MM OR 6MM 316-GRADE SWAGED WIRE) TENSIONED BETWEEN STEEL POST UPRIGHTS AT 1200MM TO 1500MM CENTRES GIVE A CONTEMPORARY INDUSTRIAL AESTHETIC. THE CABLE HORIZONTAL SPACING MUST PASS THE 100MM SPHERE TEST — IN PRACTICE, MAXIMUM 99MM VERTICAL CENTRE-TO-CENTRE SPACING ON HORIZONTAL CABLES. CARL STAHL CABLEFLEX, RONSTAN, AND IDS BALUSTRADE SYSTEMS ARE THE MAIN SUPPLIERS.

STEEL ROD BALUSTRADE: 12MM OR 16MM ROUND-SECTION STAINLESS OR MILD STEEL VERTICAL RODS WELDED TO A TOP RAIL AND BOTTOM RAIL OR BASE PLATE — THE STRUCTURAL STEEL BALUSTRADE LOOK. RODS AT MAX 99MM CENTRES. CAN BE POWDER-COATED (RAL 9005 MATT BLACK IS THE MOST POPULAR CONTEMPORARY COLOUR) OR LEFT IN BRUSHED STAINLESS FINISH. MILLENIUM GLASS AND BALUSTRADE, SHEERLINE, AND SOLO HOUSING SOLUTIONS SUPPLY STANDARD ROD BALUSTRADE SYSTEMS.

A CREAKING VICTORIAN STAIRCASE IS ALMOST ALWAYS DUE TO LOOSE JOINTS BETWEEN TREADS AND RISERS, LOOSE WEDGES BENEATH TREADS AT THE STRING, OR MOVEMENT AT THE HOUSING JOINTS WHERE TREADS AND RISERS FIT INTO THE CLOSED STRING ROUTED GROOVES.

REPAIR FROM BELOW IS THE MOST EFFECTIVE AND LEAST DISRUPTIVE METHOD WHERE THERE IS ACCESS FROM BELOW (E.G., THROUGH AN UNDERSTAIRS CUPBOARD OR AN OPEN UNDERSIDE). THE REPAIR SEQUENCE IS: CLEAN OUT OLD GLUE FROM THE WEDGE HOUSINGS. APPLY PVA ADHESIVE TO ALL TREAD-RISER JOINTS, RISER-TO-TREAD-BRACKET JOINTS, AND WEDGE FACES. DRIVE TIGHTENED WEDGES BACK INTO THE STRING HOUSINGS AGAINST THE UNDERSIDE OF THE TREADS AND BACKS OF THE RISERS. ADDITIONALLY, GLUE AND SCREW 50X50MM OR 75X75MM TIMBER GLUE BLOCKS INTO THE INTERNAL ANGLE BETWEEN EACH TREAD AND RISER — THESE ARE THE MOST EFFECTIVE ANTI-CREAK MEASURE AVAILABLE.

WHERE ACCESS FROM BELOW IS NOT POSSIBLE, CREAKING TREADS ARE ADDRESSED FROM ABOVE: DRILL THROUGH THE TREAD NOSING AT A SLIGHT ANGLE TO ENGAGE THE RISER BELOW AND DRIVE 4.0X75MM STAINLESS COUNTERSUNK SCREWS (TYPICALLY 3 PER TREAD AT 150MM CENTRES), COUNTERSINKING AND PELLETING WITH MATCHING TIMBER PELLETS FOR A CLEAN FINISH.

WHERE TREADS ARE SPLIT, WARPED, OR EXCESSIVELY WORN, REPLACEMENT WITH NEW SOLID OAK OR PINE TREADS (25MM SOLID OAK — GENERALLY AVAILABLE FROM STAIRCASE COMPONENT SUPPLIERS IN STANDARD GOING DIMENSIONS) IS STRAIGHTFORWARD PROVIDED THE STRING HOUSING DIMENSIONS ARE AVAILABLE OR THE TREAD IS SURFACE-FIXED RATHER THAN HOUSED.

FOR OPEN-PLAN LOWER GROUND FLOOR EXTENSIONS IN LONDON TERRACES WHERE A NEW STEEL STRUCTURE STAIRCASE IS SPECIFIED, THE STRUCTURAL ENGINEER DESIGNS THE STEEL FRAME (TYPICALLY RHS STRINGERS WITH PLATE TREADS) WITH THE STAIRCASE MANUFACTURER — USUALLY A SPECIALIST METALWORK FABRICATOR SUCH AS STAIRCASE STUDIO OR EZ STAIRS.

STAIRCASE RENOVATION COSTS IN LONDON VARY WIDELY DEPENDING ON THE SCOPE OF WORKS AND SPECIFICATION LEVEL. INDICATIVE RANGES FOR A STANDARD GROUND-TO-FIRST-FLOOR STAIRCASE IN A VICTORIAN TERRACE (APPROXIMATELY 13 TREADS + LANDING) ARE AS FOLLOWS.

STRUCTURAL TIGHTENING ONLY (GLUE BLOCKS, WEDGE RETIGHTENING, SCREW FIXING FROM ABOVE OR BELOW): £300 TO £700 FOR A FULL STAIRCASE.

TIMBER BALUSTRADE REPLACEMENT (REMOVE OLD BALUSTERS AND HANDRAIL, FIT NEW OAK TURNED BALUSTERS AT 99MM CENTRES, NEW OAK NEWEL CAPS, NEW OAK MOPSTICK HANDRAIL, DECORATED): £1,800 TO £4,500 DEPENDING ON BALUSTRADE DESIGN AND NEWEL POST SPECIFICATION.

FRAMELESS GLASS BALUSTRADE (CHANNEL-BASE SYSTEM, 17.5MM LTG PANELS, STRUCTURAL CALCULATION INCLUDED, SUPPLY AND FIT): £4,500 TO £9,000 FOR A STANDARD STRAIGHT-FLIGHT STAIRCASE.

POST-MOUNTED GLASS BALUSTRADE (STAINLESS STEEL POSTS + GLASS INFILL, SUPPLY AND FIT): £3,500 TO £7,000.

STEEL CABLE BALUSTRADE (CABLEFLEX OR SIMILAR, STAINLESS STEEL POSTS AND CABLES, SUPPLY AND FIT): £2,500 TO £6,000.

COMPLETE STAIRCASE REPLACEMENT (NEW TIMBER CUT STRING OAK STAIRCASE, OAK TREADS, CLOSED RISERS, GLASS BALUSTRADE, STRUCTURAL ENGINEER FEE FOR REVISED STRUCTURE): £8,000 TO £22,000 DEPENDING ON DESIGN, SPAN, AND SPECIFICATION.

BUILDING CONTROL APPROVAL IS REQUIRED FOR ANY STAIRCASE ALTERATION THAT CHANGES THE STRUCTURAL CONFIGURATION OR MAKES SIGNIFICANT CHANGES TO THE GUARDING SYSTEM — FEES APPROXIMATELY £350 TO £600 WITH A LONDON LOCAL AUTHORITY.