- Cookie Policy
- Home
- 1 Welcome
- 2 Introduction
- 3 General
- 3.1 Concrete and its reinforcement
- 3.1.1 Compliance
- 3.1.2 Provision of information
- 3.1.3 Storage of materials
- 3.1.4 Site-mixed concrete
- 3.1.5 Ready-mixed concrete
- 3.1.6 Concrete specification
- 3.1.7 Admixtures
- 3.1.8 Special types of concrete
- 3.1.9 Design of reinforced concrete
- 3.1.10 Installation of reinforcement
- 3.1.11 Blinding concrete
- 3.1.12 Formwork
- 3.1.13 Before concreting
- 3.1.14 Casting
- 3.1.15 Curing
- 3.1.16 Testing
- 3.1.17 Glossary
- 3.2 Cold weather working
- 3.3 Timber preservation (natural solid timber)
- 3.1 Concrete and its reinforcement
- 4 Foundations
- 4.1 Land quality – managing ground conditions
- 4.1.1 Compliance
- 4.1.2 Initial Assessment – desk study (all sites)
- 4.1.3 Initial Assessment – walkover survey (all sites)
- 4.1.4 Initial Assessment – results
- 4.1.5 Basic Investigation (sites where hazards are not identified or suspected)
- 4.1.6 Detailed Investigation (sites where hazards are identified or suspected)
- 4.1.7 Managing the risks (sites where hazards are found)
- 4.1.8 Unforeseen hazards
- 4.1.9 Documentation and verification
- 4.1.10 Guidance for investigations
- 4.1.11 Further information
- 4.2 Building near trees
- 4.2.1 Compliance
- 4.2.2 Provision of information
- 4.2.3 Building near trees
- 4.2.4 The effects of trees on shrinkable soils
- 4.2.5 Foundations in all soil types
- 4.2.6 Excavation of foundations
- 4.2.7 Foundations in shrinkable soils
- 4.2.8 Design and construction of foundations in shrinkable soils
- 4.2.9 Foundation depths for specific conditions in shrinkable soils
- 4.2.10 Heave precautions
- 4.2.11 New drainage
- 4.2.12 Foundation depth charts
- 4.2.13 Foundation depth tables
- 4.2.14 Example
- 4.2.15 Further information
- 4.3 Strip and trench fill foundations
- 4.3.1 Compliance
- 4.3.2 Provision of information
- 4.3.3 Ground conditions
- 4.3.4 Hazardous ground
- 4.3.5 Setting out
- 4.3.6 Services and drainage
- 4.3.7 Safe transmission of loads
- 4.3.8 Sloping ground and stepped foundations
- 4.3.9 Excavations
- 4.3.10 Reinforcement
- 4.3.11 Concrete
- 4.3.12 Movement joints
- 4.3.13 Construction joints
- 4.4 Raft, pile, pier and beam foundations
- 4.4.1 Compliance
- 4.4.2 Provision of information
- 4.4.3 Site conditions
- 4.4.4 Hazardous ground
- 4.4.5 Services and drainage
- 4.4.6 Safe transmission of loads
- 4.4.7 Construction
- 4.4.8 Engineer checks
- 4.4.9 Compressible materials
- 4.4.10 Reinforcement
- 4.4.11 Concrete
- 4.4.12 Movement joints
- 4.4.13 Resistance to moisture
- 4.5 Vibratory ground improvement techniques
- 4.5.1 Compliance
- 4.5.2 Hazardous sites and ground hazards
- 4.5.3 Desk study and site investigation
- 4.5.4 Confirmation of suitability for treatment
- 4.5.5 Suitability of ground conditions
- 4.5.6 Compatibility of the ground, design and treatment
- 4.5.7 Acceptable methods
- 4.5.8 Materials for use as fill
- 4.5.9 Granular material
- 4.5.10 Sitework
- 4.5.11 Adjacent excavations
- 4.5.12 Verification of completed treatment
- 4.1 Land quality – managing ground conditions
- 5 Substructure, Ground Floors, Drainage and Basements
- 5.1 Substructure and ground-bearing floors
- 5.1.1 Compliance
- 5.1.2 Provision of information
- 5.1.3 Transfer of loads
- 5.1.4 Ground conditions
- 5.1.5 Services and drainage
- 5.1.6 Ground below fill
- 5.1.7 Fill below floors
- 5.1.8 Infill up to 600mm deep
- 5.1.9 Materials used for fill
- 5.1.10 Harmful or toxic materials
- 5.1.11 Regulatory solutions
- 5.1.12 Walls below the DPC
- 5.1.13 Durability
- 5.1.14 Mortar
- 5.1.15 Wall ties
- 5.1.16 Blinding
- 5.1.17 Ground floor slab and concrete
- 5.1.18 Laying the ground-bearing floor slab
- 5.1.19 Damp proof course
- 5.1.20 Damp proofing concrete floors
- 5.1.21 Thermal insulation
- 5.1.22 Installation of insulation
- 5.1.23 Further information
- 5.2 Suspended ground floors
- 5.2.1 Compliance
- 5.2.2 Provision of information
- 5.2.3 Contaminants
- 5.2.4 Proprietary systems
- 5.2.5 Transfer of loads: concrete floors
- 5.2.6 Reinforced concrete
- 5.2.7 Construction of suspended concrete ground floors
- 5.2.8 Transfer of loads: timber floors
- 5.2.9 Thermal insulation and cold bridging
- 5.2.10 Damp-proofing and ventilation
- 5.2.11 Floor finishes
- 5.2.12 Floor decking
- 5.3 Drainage below ground
- 5.3.1 Compliance
- 5.3.2 Provision of information
- 5.3.3 Preliminary work
- 5.3.4 Foul and surface water disposal
- 5.3.5 Drainage system performance
- 5.3.6 Ground water drainage
- 5.3.7 Design to avoid damage and blockages
- 5.3.8 Durability
- 5.3.9 Septic tanks and cesspools
- 5.3.10 Septic tank outputs
- 5.3.11 Surface water soakaways
- 5.3.12 Component requirements
- 5.3.13 Excavation
- 5.3.14 Protection of pipework
- 5.3.15 Laying pipework
- 5.3.16 Protection of work
- 5.3.17 Testing
- 5.4 Waterproofing of basements and other below ground structures
- 5.1 Substructure and ground-bearing floors
- 6 Superstructure (excluding roofs)
- 6.1 External masonry walls
- 6.1.1 Compliance
- 6.1.2 Provision of information
- 6.1.3 Structural design
- 6.1.4 Fire resistance
- 6.1.5 Acoustic resistance
- 6.1.6 Exposure
- 6.1.7 Thermal insulation
- 6.1.8 Concrete blocks
- 6.1.9 Bricks
- 6.1.10 Stone masonry
- 6.1.11 Construction of masonry walls
- 6.1.12 Lintels
- 6.1.13 Materials suitable for mortar
- 6.1.14 Mortar
- 6.1.15 Render
- 6.1.16 Cladding
- 6.1.17 DPCs and cavity trays
- 6.1.18 Wall ties and bed joint reinforcements
- 6.1.19 Handling materials
- 6.1.20 Protection of the works during construction
- 6.2 External timber framed walls
- 6.2.1 Compliance
- 6.2.2 Provision of information
- 6.2.3 Design checking and certification
- 6.2.4 Load-bearing walls
- 6.2.5 Fixing the frame
- 6.2.6 Nails and staples
- 6.2.7 Sheathing
- 6.2.8 Differential movement
- 6.2.9 Fire resistance
- 6.2.10 Protection from moisture
- 6.2.11 Timber preservation
- 6.2.12 Vapour control layers
- 6.2.13 Breather membranes
- 6.2.14 Wall ties and fixings
- 6.2.15 Insulation
- 6.3 Internal walls
- 6.3.1 Compliance
- 6.3.2 Provision of information
- 6.3.3 Supporting load-bearing internal walls
- 6.3.4 Masonry walls
- 6.3.5 Load-bearing timber walls
- 6.3.6 Fire resistance
- 6.3.7 Sound insulation
- 6.3.8 Partitions: internal non load-bearing
- 6.3.9 Construction of timber partitions
- 6.3.10 Construction of steel framed partitions
- 6.3.11 Construction of proprietary systems
- 6.3.12 Plasterboard
- 6.3.13 Damp-proof courses
- 6.3.14 Components
- 6.4 Timber and concrete upper floors
- 6.4.1 Compliance
- 6.4.2 Provision of information
- 6.4.3 Upper floor design
- 6.4.4 Fire spread
- 6.4.5 Sound insulation
- 6.4.6 In-situ concrete floors and concreting
- 6.4.7 Precast concrete
- 6.4.8 Timber joist spans
- 6.4.9 Timber joists
- 6.4.10 Construction of timber floors
- 6.4.11 Joists supported by intermediate walls
- 6.4.12 Joists connected to steel
- 6.4.13 Joists into hangers
- 6.4.14 Timber joist and restraint strap
- 6.4.15 Strutting
- 6.4.16 Joists and openings
- 6.4.17 Multiple joists
- 6.4.18 Notching and drilling
- 6.4.19 Floor decking
- 6.4.20 Floating floors or floors between homes
- 6.5 Steelwork
- 6.6 Staircases
- 6.6.1 Compliance
- 6.6.2 Provision of information
- 6.6.3 Fire precautions
- 6.6.4 Lighting
- 6.6.5 Glazing
- 6.6.6 Structural design
- 6.6.7 Headroom and width
- 6.6.8 Design of steps
- 6.6.9 Landings
- 6.6.10 Guarding
- 6.6.11 Handrails
- 6.6.12 Staircases made from timber and wood-based products
- 6.6.13 Concrete staircases
- 6.6.14 Steel staircases
- 6.6.15 Proprietary staircase units
- 6.6.16 Protection
- 6.7 Doors, windows and glazing
- 6.8 Fireplaces, chimneys and flues
- 6.8.1 Compliance
- 6.8.2 Provision of information
- 6.8.3 Solid fuel – fireplaces and hearths
- 6.8.4 Solid fuel – combustion air
- 6.8.5 Solid fuel – flue pipes
- 6.8.6 Solid fuel – chimneys
- 6.8.7 Solid fuel – outlets and terminals
- 6.8.8 Gas – fireplaces and hearths
- 6.8.9 Gas – combustion air
- 6.8.10 Gas – flue pipes
- 6.8.11 Gas – chimneys
- 6.8.12 Gas – outlets and terminals
- 6.8.13 Oil – fireplaces and hearths
- 6.8.14 Oil – combustion air
- 6.8.15 Oil – flue pipes
- 6.8.16 Oil – chimneys
- 6.8.17 Oil – outlets and terminals
- 6.8.18 All – fireplaces and hearths
- 6.8.19 All – fireplace surrounds
- 6.8.20 All – flue pipes
- 6.8.21 All – flue liners
- 6.8.22 All – flues
- 6.8.23 All – chimneys
- 6.8.24 Masonry
- 6.8.25 Mortar
- 6.8.26 DPC
- 6.8.27 Flashings
- 6.8.28 Terminals
- 6.8.29 Flue testing
- 6.8.30 Further information
- 6.9 Curtain walling and cladding
- 6.9.1 Compliance
- 6.9.2 Provision of information
- 6.9.3 Certification
- 6.9.4 Loads
- 6.9.5 Support and fixings
- 6.9.6 Durability
- 6.9.7 Interfaces
- 6.9.8 Insulation
- 6.9.9 Damp proofing and vapour control
- 6.9.10 Installation and tolerances
- 6.9.11 Electrical continuity and earth bonding
- 6.9.12 Maintenance
- 6.9.13 Glazing, gaskets and sealants
- 6.9.14 Cavity barriers and firestops
- 6.9.15 Ventilation screens
- 6.9.16 Handling and storage
- 6.9.17 Curtain walling
- 6.9.18 Rainscreen cladding
- 6.9.19 Insulated render and brick slip cladding
- 6.10 Light steel framed walls and floors
- 6.10.1 Compliance
- 6.10.2 Provision of information
- 6.10.3 Structural certification
- 6.10.4 Structural design of load-bearing floors and walls
- 6.10.5 Structural design of infill walls
- 6.10.6 Roofs
- 6.10.7 Steel and fixings
- 6.10.8 Detailing of steel joists
- 6.10.9 Restraint
- 6.10.10 Construction of load-bearing walls and external infill walls
- 6.10.11 Interfaces with staircases
- 6.10.12 Fixing floor decking and ceilings
- 6.10.13 Other design issues
- 6.10.14 Behaviour in relation to fire
- 6.10.15 Acoustic performance
- 6.10.16 Moisture control
- 6.10.17 Insulation
- 6.10.18 Vapour control layers
- 6.10.19 Breather membranes
- 6.10.20 Cladding, lining and sheathing boards
- 6.10.21 Wall ties
- 6.10.22 Services
- 6.10.23 Further information
- 6.11 Render
- 6.1 External masonry walls
- 7 Roofs
- 7.1 Flat roofs, terraces and balconies
- 7.1.1 Compliance
- 7.1.2 Provision of information
- 7.1.3 Flat roof, terrace and balcony general design
- 7.1.4 Drainage
- 7.1.5 Flat roof, terrace and balcony structural design
- 7.1.6 Timber structure and deck
- 7.1.7 Concrete decks
- 7.1.8 Profiled self-supporting metal decks
- 7.1.9 Profiled self-supporting metal roofing
- 7.1.10 Thermal insulation and vapour control
- 7.1.11 Waterproofing layer and surface treatments
- 7.1.12 Green and biodiverse (brown roofs) – including roof gardens
- 7.1.13 Blue roofs
- 7.1.14 Raised Podium
- 7.1.15 Detailing of flat roofs
- 7.1.16 Accessible thresholds and upstands
- 7.1.17 Parapets and guarding to terraces and balconies
- 7.2 Pitched roofs
- 7.2.1 Compliance
- 7.2.2 Provision of information
- 7.2.3 Design of pitched roofs
- 7.2.4 Protection of trusses
- 7.2.5 Durability
- 7.2.6 Wall plates
- 7.2.7 Joints and connections
- 7.2.8 Restraint
- 7.2.9 Bracing for trussed rafter roofs
- 7.2.10 Strutting for attic trusses and cut roofs that form a floor
- 7.2.11 Support for equipment
- 7.2.12 Access
- 7.2.13 Dormer construction
- 7.2.14 Underlay and sarking
- 7.2.15 Ventilation, vapour control and insulation
- 7.2.16 Firestopping and cavity barriers
- 7.2.17 Battens
- 7.2.18 Roof coverings
- 7.2.19 Fixing tiles and slates
- 7.2.20 Weathering details
- 7.2.21 Valleys and hidden gutters
- 7.2.22 Drainage
- 7.2.23 Fascias and trim
- 7.2.24 Spandrel panels in cold roofs
- 7.1 Flat roofs, terraces and balconies
- 8 Services
- 8.1 Internal services
- 8.1.1 Compliance
- 8.1.2 Provision of information
- 8.1.3 Water services and supply
- 8.1.4 Cold water storage
- 8.1.5 Hot water service
- 8.1.6 Soil and waste systems
- 8.1.7 Electrical services and installations
- 8.1.8 Gas service installations
- 8.1.9 Meter Boxes
- 8.1.10 Space heating systems
- 8.1.11 Installation
- 8.1.12 Extract ducts
- 8.1.13 Testing and commissioning
- 8.2 Low or zero carbon technologies
- 8.2.1 Compliance
- 8.2.2 Provision of information
- 8.2.3 Clean Air Act
- 8.2.4 System design
- 8.2.5 Access
- 8.2.6 Handling, storage and protection
- 8.2.7 Sequence of work
- 8.2.8 Location
- 8.2.9 Building integration
- 8.2.10 Fixing
- 8.2.11 Electrical installation requirements
- 8.2.12 Pipes, insulation and protection from cold
- 8.2.13 Ground collectors
- 8.2.14 Fuel storage
- 8.2.15 Safe discharge
- 8.2.16 Testing and commissioning
- 8.2.17 Handover requirements
- 8.2.18 Further information
- 8.3 Mechanical ventilation with heat recovery
- 8.1 Internal services
- 9 Finishes
- 9.1 A consistent approach to finishes
- 9.1.1 Compliance
- 9.1.2 External walls
- 9.1.3 Internal walls and ceilings
- 9.1.4 Doors and windows
- 9.1.5 Floors
- 9.1.6 Glazing
- 9.1.7 Ceramic, concrete, terrazzo and similar tile finishes
- 9.1.8 Fitted furniture
- 9.1.9 Joint sealants
- 9.1.10 Paint finishes
- 9.1.11 Sanitary ware
- 9.1.12 Other surfaces and components
- 9.1.13 Pitched roof coverings
- 9.1.14 Garages
- 9.1.15 External works
- 9.2 Wall and ceiling finishes
- 9.3 Floor finishes
- 9.4 Finishes and fitments
- 9.5 Painting and decorating
- 9.1 A consistent approach to finishes
- 10 External works
- 10.1 Garages
- 10.2 Drives, paths and landscaping
- 10.2.1 Compliance
- 10.2.2 Provision of information
- 10.2.3 Stability
- 10.2.4 Freestanding walls and retaining structures
- 10.2.5 Guarding and steps
- 10.2.6 Drives, paths and landscaping
- 10.2.7 Materials
- 10.2.8 Garden areas within 3m of the home
- 10.2.9 Garden areas
- 10.2.10 Timber decking
- 10.2.11 Landscaping
Also see:
5.1
4.4.6Safe transmission of loads
Raft, pile, pier and beam foundations shall be designed to transmit loads from the structure to the ground safely, without excessive settlement.
Raft, pile, pier and beam foundations should safely transmit loads. The following issues should be taken into account:
- adequate stiffness to ensure that differential movement does not adversely affect the supported structure
- nature and bearing capacity of the fill material to be placed under the foundation
- specification of concrete and cover to reinforcement.
- to prevent the erosion of ground beneath the raft
- (where required) to accommodate warm air ducts, service ducts or services without any adverse effect upon the performance of the foundation
- to limit the risk of ducts becoming flooded
- to support the building envelop without the risk of differential movement between leaves of cavity walls.
- raft foundations are to be designed by a chartered civil or structural engineer taking account of ground conditions and the results of the site appraisal and ground assessment
- sufficient internal beams are to be provided to stiffen the slab adequately
- the area between downstand beams should not be greater than 35m2
- the ratio of adjacent sides on plan should not exceed 2:1
- the minimum depth of perimeter and party wall beams is to be 450mm. On larger homes, some internal beams should be of the same depth as the perimeter beams
- perimeter and internal beams should be sufficiently wide at their base to carry their total loading at the allowable bearing pressure for the site
- beams are to be designed to span 3m simply supported and cantilever 1.5m
- beams are to use properly formed reinforcement in accordance with BS EN 1992-1-1
- where mesh is used in beams, it should be delivered to the site pre-bent
- all beams should be cast on a minimum of 50mm concrete blinding
- minimum cover to reinforcement should be 40mm
- floor slabs should be a minimum 150mm thick, with nominal top face reinforcement as a minimum and anti-crack reinforcement in the bottom face, where appropriate
- stools or similar should be used to support floor slab mesh during casting
- corners and junctions to beams should be adequately tied using similar reinforcement to the beams
- a minimum cavity drain of 225mm below the DPC is to be maintained.
Raft and semi-raft foundations:
Raft and semi-raft foundations should be designed:
Fill for raft foundations should be in accordance with Chapter 5.1 ‘Substructure and ground-bearing floors’.
Semi-raft foundations on made ground:
The following notes are to be used as a guide for engineers designing raft foundations, but are by no means exhaustive. Special consideration will be required for certain sites.
Piled foundations:
The design of all piled foundations should specify precautions for cohesive soils where volume changes can occur.
The bearing capacity and integrity of piles should be confirmed by testing, when required.