6.9 Curtain walling and cladding

MATERIALS STANDARDS

6.9 - M1Materials standards
6.9 - M2Dpc/Dpm materials
6.9 - M3Glazing
6.9 - M4Gaskets
6.9 - M5Sealant
6.9 - M6Thermal insulation
6.9 - M7Breather membranes
6.9 - M8Cavity barriers and fire-stops
6.9 - M9Fixings
6.9 - M10Timber preservation
6.9 - M11Ventilation screens

6.9 - M1
All materials shall:
(a) meet the technical requirements
(b) take account of the design
 

Materials that comply with the design and the guidance below will be acceptable for curtain walling, rainscreen cladding, insulated render and brick slip cladding systems.

Materials for curtain walling, rainscreen cladding, insulated render and brick slip cladding systems should comply with all relevant standards, including those listed below. Where no standard exists, Technical Requirement R3 applies (see Chapter 1.1 'Introduction to the Standards and Technical Requirements').

References to British Standards and Codes of Practice include those made under the Construction Products Directive (89/106/EEC) and, in particular, appropriate European Technical Specifications approved by a European Committee for Standardisation (CEN).

DPC/DPM MATERIALS

6.9 - M2
Materials for damp-proofing shall resist adequately the passage of moisture
 

Items to be taken into account include:

(a) dpcs/dpms

The following materials are acceptable for use as dpcs/dpms:

Materials for dpcs/dpms should be compatible with adjoining materials.

Dpcs/dpms and flexible cavity trays should be of the correct dimensions to suit the detailed design.

For complicated junctions, preformed cavity trays are recommended.

(b) flashings

The following are acceptable as flashings:

  • rolled lead sheet (at least code 4) complying with BS EN 12588
  • aluminium and aluminium alloys to BS EN 485 and BS EN 573
  • zinc alloys to BS EN 988
  • stainless steel.

Aluminium and aluminium alloys should not come into contact with cementitious material.

GLAZING

6.9 - M3
Glazing shall be as required by the design
 

Reference should be made to Chapter 6.7 'Doors, windows and glazing' (each section) for guidance on glazing.

GASKETS

6.9 - M4
Materials for gaskets shall provide satisfactory performance
 

Extruded rubber gaskets should comply with BS 4255.

Other materials may be used if satisfactorily assessed in accordance with Technical Requirement R3.

SEALANT

6.9 - M5
Materials for sealant shall provide satisfactory performance
 

Sealant should be selected and applied in accordance with BS 6213 and BS EN ISO 11600.

Sealant to be used in locations where differential movement may be expected, e.g. interfaces between the façade and the structure, should be one of the following:

  • two part polysulphide
  • one part polysulphide
  • one part silicone
  • one or two part polyurethane.

Other materials may be used if satisfactorily assessed in accordance with Technical Requirement R3.

THERMAL INSULATION

6.9 - M6
Insulation materials shall provide the degree of insulation to comply with the design
 

Insulation materials should be inert, durable, rot and vermin proof and should not be adversely affected by moisture or vapour.

Insulation materials that comply with the following Standards are acceptable:

  • mineral wool to BS EN 13162
  • FR grade (flame retardant) expanded polystyrene to BS EN 13163
  • FR grade (flame retardant) extruded polystyrene to BS EN 13164
  • rigid polyurethane foam and polyisocyanurate to BS EN 13165
  • phenolic foam to BS EN 13166
  • cellular glass to BS EN 13167.

Other materials may be used if satisfactorily assessed in accordance with Technical Requirement R3.

BREATHER MEMBRANES

6.9 - M7
Breather membranes shall be durable and be capable of allowing water vapour to pass outwards and prevent moisture from penetrating inwards
 

Breather membranes should comply with BS 4016 (Type 1 in areas of very severe exposure).

Other materials may be used if satisfactorily assessed in accordance with Technical Requirement R3.

CAVITY BARRIERS AND FIRE-STOPS

6.9 - M8
Materials used for cavity barriers and fire-stops shall be capable of providing adequate resistance to fire and smoke
 

Materials specified in statutory requirements are acceptable.

Other materials may be used if satisfactorily assessed in accordance with Technical Requirement R3.

Systems incorporating proprietary intumescent materials should follow the guidance provided by The Intumescent Fire Seals Association (IFSA) and the Association for Specialist Fire Protection (ASFP).

FIXINGS

6.9 - M9
Fixings shall be of durable material and provide satisfactory performance
 

Fixings should be manufactured from:

  • phosphor bronze
  • silicon bronze
  • stainless steel to BS EN ISO 3506
  • mild steel with coatings to BS EN 12329, BS EN 12330, BS EN 1461, or other appropriate treatment in accordance with BS EN ISO 12944 or BS EN ISO 14713
  • aluminium alloy to BS EN 573 and BS EN 755
  • appropriate plastics.

Materials that comply with recognised Standards, which provide equal or better performance to those above, would also be acceptable.

Other materials may be used if satisfactorily assessed in accordance with Technical Requirement R3.

Aluminium and aluminium alloys should not come into contact with cementitious material.

TIMBER PRESERVATION

6.9 - M10
Timber shall be either naturally durable or preservative treated to provide adequate protection against rot and insect attack
 

Reference should be made to Chapter 2.3 'Timber preservation (natural solid timber)' (each section) for guidance on preservative treatments.

VENTILATION SCREENS

6.9 - M11
Ventilation openings shall be protected from the entry of birds and animals
 

Ventilation openings where the least dimension exceeds 10mm should be protected to prevent the entry of birds and animals.

Acceptable protection of openings can be provided by:

  • rigid fabrications with width of opening greater than 3mm and less than 10mm (no restriction on length)
  • rigid fabrications with round holes greater than 3mm and less than 10mm diameter
  • square or rectangular mesh where the clear opening size is greater than 3mm and less than 10mm.