Builders

VertDivider

Technical Guidance

Foreword

To address some of the frequently asked questions of NHBC Standards and Technical we have developed the following Technical Guidance to amplify some of the detail contained in the NHBC Standards.

The Technical Guidance is referenced using the same format as the NHBC Standards.

I hope you will find this information a useful addition to the NHBC website and any feedback you may wish to provide, including new areas to be included, will be very welcome.

Kind Regards

Graham Perrior
Acting Group Head of Standards and Technical.

Disclaimer

Information contained within 'Technical Guidance' is for general purposes and guidance only and it is addressed to persons who are competent construction industry workers.  It contains only brief summaries of aspects of the subject matter and does not provide comprehensive statements of the relevant construction industry practice.  It does not constitute professional advice and does not provide a substitute for it.  All information relates to circumstances prevailing at the date of publication and will not be updated to reflect subsequent developments.

General

1.0/01 New home built alongside existing home
1.0/02 Japanese Knotweed
1.0/03 Conversions and renovations

NHBC Standards Chapter 4.2 Building near trees

4.2/01 Strip/trench fill foundations - slip membranes

NHBC Standards Chapter 4.4 Strip and trench fill foundations

4.4/01 Foundation concrete
4.4/02 Steps in foundations
4.4/03 Minimum foundation depths in clay soils

NHBC Standards Chapter 4.5 Raft, pile, pier and beam foundations

4.5/01 Raft foundations - edge detail

NHBC Standards Chapter 5.2 Suspended ground floors

5.2/01 In-situ concrete suspended ground floors
5.2/02 Precast concrete floor planks to ground floors
5.2/03 Radon protection - provision of sump

NHBC Standards Chapter 5.3 Drainage below ground

5.3/01 Drainage - connections to pre-formed inspection chamber bases
5.3/02 Lightweight drainage covers
5.3/03 Access to manholes/inspection chambers
5.3/04 'Y' junctions in drains under buildings
5.3/05 Field drainage systems in septic tanks and small private sewerage treatment plants

NHBC Standards Chapter 6.1 External masonry walls

6.1/01 Partial fill insulation to gable walls
6.1/02 Movement joints - slip ties
6.1/03 Small pediment gable walls
6.1/04 Corrosion protection to render beads
6.1/05 Dpc trays above soldier courses/stone heads
6.1/06 Dpc trays to rendered walls
6.1/08 Cavity walls - stopping cavities at the junction with separating walls
6.1/09 Installation of lead flashings
6.1/10 Bedding lintels
6.1/11 Movement joints below dpc
6.1/12 Restraint straps to gable walls of garages
6.1/13 Damp proofing around meter boxes
6.1/14 Movement joints in clay brick masonry
6.1/15 Cavity trays to bay windows
6.1/16 Masonry bed joint reinforcement
6.1/17 Toothing of brickwork
6.1/18 Concrete fill in a cavity wall
6.1/19 Ducts/flues through core drilled holes
6.1/20 Block bonding
6.1/21 Movement joints in masonry

NHBC Standards Chapter 6.2 External timber framed walls

6.2/01 Socket outlets - fire barriers
6.2/03 Ventilation of cavities
6.2/04 External timber framed walls - movement gaps at eaves and verges
6.2/08 Rendering on timber framed walls

NHBC Standards Chapter 6.3 Internal walls

6.3/01 Firestopping to garage walls
6.3/02 Separating walls - cavity insulation
6.3/03 Dpcs under timber soleplates to internal partitions
6.3/04 Separating wall construction within roof spaces
6.3/06 Timber stud partitions
6.3/07 Sockets and switches in light steel framed separating walls

NHBC Standards Chapter 6.4 Timber and concrete upper floors

6.4/03 End support to chipboard flooring
6.4/04 Noggings for lateral restraint straps
6.4/05 Bolt fixing of multiple joists
6.4/06 Strutting to floor joists
6.4/07 Sealing around ends of engineering joists
6.4/08 Support of plasterboard
6.4/09 Support of joist hangers
6.4/10 Recessed light fittings in ceilings to intermediate floors in houses
6.4/11 Lateral restraint straps to beam and block and precast or prestressed intermediate floors

NHBC Standards Chapter 6.5 Steelwork support to upper floors and partitions

6.5/01 Steel beams - parallel connections

NHBC Standards Chapter 6.6 Staircases

6.6/01 Handrail to staircases - tapered treads/winders
6.6/03 Stair nosings
6.6/04 Guarding to treads and risers
6.6/05 Risers to private stairs - thick floor coverings

NHBC Standards Chapter 6.7 Doors, windows and glazing

6.7/01 Gaps around PVC-U windows
6.7/02 Door limitation devices
6.7/04 Background ventilation to utility rooms
6.7/05 Gaps around timber windows and timber door frames
6.7/07 Door between an integral garage and the dwelling - security
6.7/08 Egress windows and conservatories
6.7/11 Fire doors to bathrooms
6.7/12 Window restrictors and protection against falling

NHBC Standards Chapter 6.8 Chimneys and flues

6.8/02 Installation of gas flue pipes in roof spaces
6.8/03 Guarding to gas flue terminals
6.8/04 Termination of horizontal flues

NHBC Standards Chapter 7.1 Flat roofs and balconies

7.1/01 Balcony drainage

NHBC Standards Chapter 7.2 Pitched roofs

7.2/01 Diagonal bracing to double hipped roof
7.2/02 Plasterboard fire-resisting ceiling in contact with single leaf masonry
7.2/03 Use of nail guns for fixing trussed rafter bracing
7.2/04 Wall plates - bedding, lengths and joints
7.2/05 Bedding verge tiles
7.2/07 Lateral restraint provided by gable ladders
7.2/08 Bracing of mono-pitch roof trusses
7.2/09 Pitched roofs - bedding verge undercloaks
7.2/10 Attic trusses - bracing
7.2/11 Pitched roofs to garages - holding down straps
7.2/12 Roofng underlay at eaves level
7.2/13 Ventilation of small roofs
7.2/14 Fixing valley trussed rafters (diminishing trussed rafters)
7.2/15 Canopy flashings
7.2/16 Diagonal bracing to trussed rafters
7.2/17 Fixing roof tiles in valleys
7.2/18 Loft hatches and fire resistance
7.2/19 Vapour permeable underlays (VPUs) and roof void ventilation
7.2/20 Mortar for slating and tiling
7.2/21 Fixing tiling battens using nail guns
7.2/22 Slate hook fixing

NHBC Standards Chapter 8.1 Internal services

8.1/01 Discharge pipes from UVHWSS in garages
8.1/02 Earth bonding - certificate of compliance
8.1/05 Pipe insulation in airing cupboards
8.1/06 Earth bonding plastic plumbing
8.1/07 Use of flexible ducting to connect SVP
8.1/09 TRVs and room thermostats
8.1/10 Insulation of heating pipes in timber floors
8.1/11 Electrical - earth bonding metal back boxes
8.1/12 Sound insulation of soil pipes in floor voids
8.1/13 Extract fans - air leakage
8.1/14 Plastic plumbing - pipe support
8.1/15 Plastic plumbing - insulation
8.1/16 Air Admittance Valves
8.1/17 Wiring to wall lights
8.1/18 Consumer unit - labelling
8.1/19 Metal splashbacks - earthing/bonding
8.1/20 Sound proofing to SVP's

NHBC Standards Chapter 8.2 Wall and ceiling finishes

8.2/01 Edges of ceramic tiling
8.2/02 Dry lining to walls with chemical dpcs
8.2/03 Dry lining walls with different types of masonry
8.2/04 Edge sealing to dry lining

NHBC Standards Chapter 8.3 Floor finishes

8.3/01 Fibre reinforced screeds

NHBC Standards Chapter 9.1 Garages

9.1/02 Garage - concrete floors
9.1/03 Garage wall construction
9.1/04 Compartment walls between garages
9.1/05 Carports - fire separation

NHBC Standards Chapter 9.2 Drives, paths and landscaping

9.2/01 Log retaining walls
9.2/02 Profles for access steps
9.2/04 Disabled access to principal entrances (England & Wales)
9.2/05 Pedestrian access
9.2/06 Guarding to retaining structures
9.2/07 External steps - mobility access (England & Wales only)
9.2/08 Retaining walls across gardens