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CURTAIN WALLS
This technical specification refers to facades made of aluminium profiles and glass (curtain walls). For windows and doors in facades, see the technical specification for the manufacture and installation of facade aluminium windows and doors.
1. Relevant standards
EN 13830 (2003) Curtain walling. Product standard.
EN ISO 12631 (2017) Thermal performance of curtain walling - Calculation of thermal transmittance - Simplified procedure
EN 12152 (2002) Curtain walling - Air permeability - Performance requirements and classification
EN 12154 (1999) Curtain walling - Watertightness - Performance requirements and classification
EN 12179 (2000). Curtain walling. Resistance to wind load. Test method.
EN 13116 (2001) Curtain walling - Resistance to wind load - Performance requirements
EN 14019 (2016) Curtain Walling - Impact resistance - Performance requirements
EN 572-1 (2012) Glass in building - Basic soda lime silicate glass products - Part 1: Definitions and general physical and mechanical properties
EN 1096-1 (2012) Glass in building - Coated glass - Part 1: Definitions and classification
EN 356 (1999) Glass in building - Security glazing - Testing and classification of resistance against manual attack
EN 13022-1 (2014) Glass in building - Structural sealant glazing - Part 1: Glass products for structural sealant glazing systems for supported and unsupported monolithic and multiple glazing
EN 13022-2 (2014) Glass in building. Structural sealant glazing - Part 2: Assembly rules
EN 14449 (2005) Glass in building - Laminated glass and laminated safety glass - Evaluation of conformity/Product standard
EN 1279-1 (2018) Glass in Building - Insulating glass units - Part 1: Generalities, system description, rules for substitution, tolerances and visual quality
EN 12206-1 (2014) Paints and varnishes - Coating of aluminium and aluminium alloys for architectural purposes - Part 1: Coatings prepared from coating powder
EN 1999-1-1 (2007) Eurocode 9: Design of aluminium structures - Part 1-1: General structural rules
EN 1999-1-3 (2007) Eurocode 9: Design of aluminium structures - Part 1-3: Structures susceptible to fatigue
EN 13162 (2012) + A1 (2015) Thermal insulation products for buildings - Factory made mineral wool (MW) products - Specification
EN ISO 11600 (2003) + A1 (2011) Building construction - Jointing products - Classification and requirements for sealants
2. Material
The façade contractor is obliged to prepare a façade design that should be in accordance with the main architectural design and must contain at least the following:
- static design,
- proof that the facade meets thermal and acoustic requirements, technical description of thermal insulation materials,
- facade plans with marked positions of the elements,
- characteristic details (anchoring, windows, doors, corners, niches, decorative elements on the facade, connection with the plinth, roof cornice or horizontal surfaces, etc.),
- technical sheets and certificates for all materials and elements to be used (aluminium elements, glass, fittings, anchors, thermal insulation and waterproofing materials, steel elements, etc.),
- lighting protection,
- method statement of work including quality control plan,
- maintenance instructions.
Before making workshop drawings, the contractor should check whether there are obstacles on the structure of the building for fixing the facade, such as underfloor heating or prestressing cables in the concrete slabs, etc.
Performance characteristics (as per EN 13830) should be as follow:
- Resistance to wind load: curtain wall should meet designed performance requirements when exposed to positive and negative pressures, in accordance with EN 13116 in [kN/m2] ± 2.0,
Impact resistance: I5/E5
- Air permeability: AE
- Watertightness: RE
- Airborne sound insulation: in accordance with the design requirements
- Reaction to fire / fire resistance: in accordance with the design requirements
- Heat transmittance Ucw [W/m2k]: in accordance with the design requirements
The system of aluminium profiles should be thermally broken and drained. The finishing and colour of aluminium profiles should be in accordance with the architectural execution design (window and doors schemes). Anodized coating thickness should be approximately 20μ or powder coating 50 - 70µ, coating should be resistant to UV radiation. Coating to be done by the profile manufacturer (not in local workshops).
The elements are delivered to the construction site with profiles that are protected with self-adhesive tape or in another way.
Insert units (windows and doors) should comply with the technical specification for the manufacture and installation of facade aluminium windows and doors.
The windows should be on the external side of the facade without visible aluminium profiles.
Glass should be in accordance with the architectural design and thermal and acoustic requirements, and in particular:
- Heat transfer coefficient of glass Ug (W/m2K)
- Light transmission Lt (%)
- Light reflection LR (%)
- g-Value (Heat transmission from the sun, %)
- Colour rendering - Ra value (%)
- Airborne sound insulation Rw (dB)
Security glass must be installed on the external side of the façade.
Insulating glass spacers should be made of aluminium, perforated, filled with a highly active drying agent (molecule) that ensures a low level of moisture between the glasses or thermoplastic or silicone-based material with incorporated molecular sieves (flexible warm edge spacers).
Condensation is not allowed on the surface of aluminium profiles and glass.
Fixing anchors for windows and doors should be made of galvanized steel or stainless steel. For galvanized steel elements, the contractor is obliged to submit reports on anti-corrosion protection testing. Direct contact of different metals (galvanized steel and aluminium) is not allowed.
Before the start of work, contractor is obliged to submit manufacturer's certificates for all materials to the Supervisor for approval, through the Submittal process.
Contractor is to submit manual for maintenance and cleaning.
3. Workmanship
Before ordering materials and starting work, the contractor should make a sample of the façade, with a minimum width of one facade module and the height of one floor, and obtain the consent of the supervisor.
The contractor is obliged to survey the actual condition of structural elements and masonry parts of the facade. If the contractor determines that the condition of the building does not correspond to the designed, he should inform the supervisor before the start of works.
The allowed deviation of walls and pillars from the plane is 15 mm along the entire height of the building and 20 mm along the length of the building, with local unevenness up to 5 mm.
If curtain wall elements are stored on the construction site until installation, they should be protected from precipitation and direct sunlight and always on a base of wood or similar material (not directly on concrete, cement screed, etc.). Angles of corners of the stored frames should remain right.
Protective self-adhesive tapes should be removed as soon as possible after installation, when conditions on the construction site allow, at a temperature higher than + 10ºC.
Facade elements that were incorrectly cut and delivered to the construction site should be returned to the workshop. Modification of elements on the construction site is not allowed.
After drilling holes in the structural elements of the building for the installation of anchors, the holes must be blown out of dust. The minimum distance of the anchor to the edge of the wall or pillar is 100 mm. The minimum anchoring depth is 50mm in concrete, 80mm in a brick wall and 100mm in a wall of lightweight concrete blocks.
The verticality of the installed aluminium profiles should be controlled with a theodolite or a plumb bob.
All elements of aluminium profiles, connecting elements, thermal breaks, EPDM seals, drainage pipes, etc. should be original from the manufacturer, no improvisations are allowed. EPDM seals should be neatly cut and joined at the corners with materials that were originally recommended by the system manufacturer in accordance with the workshop drawings.
The joints of curtain wall with the building walls should be filled in layers, according to the instructions of the sealant manufacturer. The space in the middle should be filled with mineral wool or thermal insulation mass - polyurethane foam. Unless otherwise provided by the design, the joint should be closed on the outside with a waterproofing vapor-permeable sealing foil, and on the inside with a hydro and vapor barrier sealing compound or expanding tape. If it is subsequently plastered over the waterproofing foil, then the foil should be sprinkled for better adhesion of the mortar. If silicones (neutral) are used for sealing joints, then they should be (according to EN ISO 11600) type F, class 25 for external joints and minimum class 20 for internal joints.
Curtain wall and building walls joint should be protected from moisture until the external metal flashing is installed. When installing the flashing, care should be taken not to cover the condensate drainage holes from the aluminium profile and ensure that this amount of water is drained in a controlled manner.
Panels on the parapets: The joint of the aluminium or galvanized sheet metal backpan should be completely sealed with silicone, so that it is vapor-tight. Thermal insulation should be fixed to the backpans. The vapor-permeable foil on front side should be in one piece or joined according to the manufacturer's instructions. The foil should be placed so that the ventilated layer between the thermal insulation and the glass functions properly.
Before installing thermal insulation boards, consider how they will be protected from rain during the execution of works. If the thermal insulation is installed in two layers, the boards of the second layer should cover the joints of the first layer. The allowed joint between two boards is 2 mm, larger joints must be filled with the same material. It is not allowed to install wet, dirty or damaged thermal insulation boards.
The dimensions of the glass should be at least 2mm on each side less than the frame in which it is installed.
Care should be taken that the edges of the glass panels are not exposed to UV rays, before and after installation (if the edges are not filled with a mass resistant to UV rays).
Glass panels are installed on hard PVC spacer packers. Packers should provide a free space between the glass and the groove to equalize the steam pressure and condensate drainage. It is not allowed for the glass to touch the aluminium profile. Packer width should be min. 2mm wider than the width of the glass, length 80-100mm. No more than two packers should be installed on each side of the glass panel. The distance of the packer from the corner of the glass package is 50-80 mm, for glass wider than 1.5 m - up to 150 mm.
If the building walls where the curtain wall are installed are plastered and painted after installation, aluminium profiles and glass (especially anodized aluminium profiles that can be permanently damaged by the plaster) should be protected from damage during plastering. As soon as the danger of damage to the profile from mortar and painting works ceases, protective tapes to be removed.
It is not allowed to hang any elements on the elements of the curtain wall (such as canopies, advertisements, lamps, etc.) unless it is foreseen by facade design (shop drawing).
Electrical wiring and other specialist cables should be routed around and away from the curtain wall and not through the frames. If this is not possible then it must be agreed by the contractor and supervisor as to an alternative solution and if required a specialist service provider brought in to assist with the routing of the cables.
The minimum temperature at the time of installation of facade elements should be + 5ºC.
4. Supervision and measurement of works
Before installing curtain wall elements, visually check that the elements are undamaged, including the glass, especially the sealant at the edges of the glass panes.
After installing the vertical and horizontal aluminium profiles, the contractor is obliged to check the geometry and verticality of the facade in the presence of the supervisor.
All executed works should be regularly checked before they are covered and checklists should be kept regularly. Inspections should be performed and the checklists signed by the responsible person of the contractor, previously appointed by the contractor. Supervision should be notified of each inspection at least one day in advance.
The contractor is obliged to ensure the inspection of the licensed instructor of the curtain wall manufacturer at least three times during the execution of works, in different phases of works, about which he will submit report. A supervisor should be invited to these inspections.
Unless otherwise stipulated in the contract, works are calculated per m2 of completed curtain wall. Installation of anchors is calculated 5% of the value of installed curtain wall. Installation of aluminium profiles - 45%, installation of glass - 35%, installation of flashing - 10% and completion of final works and cleaning of the facade - 5%.
January, 2021
This technical specification refers to facades made of aluminium profiles and glass (curtain walls). For windows and doors in facades, see the technical specification for the manufacture and installation of facade aluminium windows and doors.
1. Relevant standards
EN 13830 (2003) Curtain walling. Product standard.
EN ISO 12631 (2017) Thermal performance of curtain walling - Calculation of thermal transmittance - Simplified procedure
EN 12152 (2002) Curtain walling - Air permeability - Performance requirements and classification
EN 12154 (1999) Curtain walling - Watertightness - Performance requirements and classification
EN 12179 (2000). Curtain walling. Resistance to wind load. Test method.
EN 13116 (2001) Curtain walling - Resistance to wind load - Performance requirements
EN 14019 (2016) Curtain Walling - Impact resistance - Performance requirements
EN 572-1 (2012) Glass in building - Basic soda lime silicate glass products - Part 1: Definitions and general physical and mechanical properties
EN 1096-1 (2012) Glass in building - Coated glass - Part 1: Definitions and classification
EN 356 (1999) Glass in building - Security glazing - Testing and classification of resistance against manual attack
EN 13022-1 (2014) Glass in building - Structural sealant glazing - Part 1: Glass products for structural sealant glazing systems for supported and unsupported monolithic and multiple glazing
EN 13022-2 (2014) Glass in building. Structural sealant glazing - Part 2: Assembly rules
EN 14449 (2005) Glass in building - Laminated glass and laminated safety glass - Evaluation of conformity/Product standard
EN 1279-1 (2018) Glass in Building - Insulating glass units - Part 1: Generalities, system description, rules for substitution, tolerances and visual quality
EN 12206-1 (2014) Paints and varnishes - Coating of aluminium and aluminium alloys for architectural purposes - Part 1: Coatings prepared from coating powder
EN 1999-1-1 (2007) Eurocode 9: Design of aluminium structures - Part 1-1: General structural rules
EN 1999-1-3 (2007) Eurocode 9: Design of aluminium structures - Part 1-3: Structures susceptible to fatigue
EN 13162 (2012) + A1 (2015) Thermal insulation products for buildings - Factory made mineral wool (MW) products - Specification
EN ISO 11600 (2003) + A1 (2011) Building construction - Jointing products - Classification and requirements for sealants
2. Material
The façade contractor is obliged to prepare a façade design that should be in accordance with the main architectural design and must contain at least the following:
- static design,
- proof that the facade meets thermal and acoustic requirements, technical description of thermal insulation materials,
- facade plans with marked positions of the elements,
- characteristic details (anchoring, windows, doors, corners, niches, decorative elements on the facade, connection with the plinth, roof cornice or horizontal surfaces, etc.),
- technical sheets and certificates for all materials and elements to be used (aluminium elements, glass, fittings, anchors, thermal insulation and waterproofing materials, steel elements, etc.),
- lighting protection,
- method statement of work including quality control plan,
- maintenance instructions.
Before making workshop drawings, the contractor should check whether there are obstacles on the structure of the building for fixing the facade, such as underfloor heating or prestressing cables in the concrete slabs, etc.
Performance characteristics (as per EN 13830) should be as follow:
- Resistance to wind load: curtain wall should meet designed performance requirements when exposed to positive and negative pressures, in accordance with EN 13116 in [kN/m2] ± 2.0,
Impact resistance: I5/E5
- Air permeability: AE
- Watertightness: RE
- Airborne sound insulation: in accordance with the design requirements
- Reaction to fire / fire resistance: in accordance with the design requirements
- Heat transmittance Ucw [W/m2k]: in accordance with the design requirements
The system of aluminium profiles should be thermally broken and drained. The finishing and colour of aluminium profiles should be in accordance with the architectural execution design (window and doors schemes). Anodized coating thickness should be approximately 20μ or powder coating 50 - 70µ, coating should be resistant to UV radiation. Coating to be done by the profile manufacturer (not in local workshops).
The elements are delivered to the construction site with profiles that are protected with self-adhesive tape or in another way.
Insert units (windows and doors) should comply with the technical specification for the manufacture and installation of facade aluminium windows and doors.
The windows should be on the external side of the facade without visible aluminium profiles.
Glass should be in accordance with the architectural design and thermal and acoustic requirements, and in particular:
- Heat transfer coefficient of glass Ug (W/m2K)
- Light transmission Lt (%)
- Light reflection LR (%)
- g-Value (Heat transmission from the sun, %)
- Colour rendering - Ra value (%)
- Airborne sound insulation Rw (dB)
Security glass must be installed on the external side of the façade.
Insulating glass spacers should be made of aluminium, perforated, filled with a highly active drying agent (molecule) that ensures a low level of moisture between the glasses or thermoplastic or silicone-based material with incorporated molecular sieves (flexible warm edge spacers).
Condensation is not allowed on the surface of aluminium profiles and glass.
Fixing anchors for windows and doors should be made of galvanized steel or stainless steel. For galvanized steel elements, the contractor is obliged to submit reports on anti-corrosion protection testing. Direct contact of different metals (galvanized steel and aluminium) is not allowed.
Before the start of work, contractor is obliged to submit manufacturer's certificates for all materials to the Supervisor for approval, through the Submittal process.
Contractor is to submit manual for maintenance and cleaning.
3. Workmanship
Before ordering materials and starting work, the contractor should make a sample of the façade, with a minimum width of one facade module and the height of one floor, and obtain the consent of the supervisor.
The contractor is obliged to survey the actual condition of structural elements and masonry parts of the facade. If the contractor determines that the condition of the building does not correspond to the designed, he should inform the supervisor before the start of works.
The allowed deviation of walls and pillars from the plane is 15 mm along the entire height of the building and 20 mm along the length of the building, with local unevenness up to 5 mm.
If curtain wall elements are stored on the construction site until installation, they should be protected from precipitation and direct sunlight and always on a base of wood or similar material (not directly on concrete, cement screed, etc.). Angles of corners of the stored frames should remain right.
Protective self-adhesive tapes should be removed as soon as possible after installation, when conditions on the construction site allow, at a temperature higher than + 10ºC.
Facade elements that were incorrectly cut and delivered to the construction site should be returned to the workshop. Modification of elements on the construction site is not allowed.
After drilling holes in the structural elements of the building for the installation of anchors, the holes must be blown out of dust. The minimum distance of the anchor to the edge of the wall or pillar is 100 mm. The minimum anchoring depth is 50mm in concrete, 80mm in a brick wall and 100mm in a wall of lightweight concrete blocks.
The verticality of the installed aluminium profiles should be controlled with a theodolite or a plumb bob.
All elements of aluminium profiles, connecting elements, thermal breaks, EPDM seals, drainage pipes, etc. should be original from the manufacturer, no improvisations are allowed. EPDM seals should be neatly cut and joined at the corners with materials that were originally recommended by the system manufacturer in accordance with the workshop drawings.
The joints of curtain wall with the building walls should be filled in layers, according to the instructions of the sealant manufacturer. The space in the middle should be filled with mineral wool or thermal insulation mass - polyurethane foam. Unless otherwise provided by the design, the joint should be closed on the outside with a waterproofing vapor-permeable sealing foil, and on the inside with a hydro and vapor barrier sealing compound or expanding tape. If it is subsequently plastered over the waterproofing foil, then the foil should be sprinkled for better adhesion of the mortar. If silicones (neutral) are used for sealing joints, then they should be (according to EN ISO 11600) type F, class 25 for external joints and minimum class 20 for internal joints.
Curtain wall and building walls joint should be protected from moisture until the external metal flashing is installed. When installing the flashing, care should be taken not to cover the condensate drainage holes from the aluminium profile and ensure that this amount of water is drained in a controlled manner.
Panels on the parapets: The joint of the aluminium or galvanized sheet metal backpan should be completely sealed with silicone, so that it is vapor-tight. Thermal insulation should be fixed to the backpans. The vapor-permeable foil on front side should be in one piece or joined according to the manufacturer's instructions. The foil should be placed so that the ventilated layer between the thermal insulation and the glass functions properly.
Before installing thermal insulation boards, consider how they will be protected from rain during the execution of works. If the thermal insulation is installed in two layers, the boards of the second layer should cover the joints of the first layer. The allowed joint between two boards is 2 mm, larger joints must be filled with the same material. It is not allowed to install wet, dirty or damaged thermal insulation boards.
The dimensions of the glass should be at least 2mm on each side less than the frame in which it is installed.
Care should be taken that the edges of the glass panels are not exposed to UV rays, before and after installation (if the edges are not filled with a mass resistant to UV rays).
Glass panels are installed on hard PVC spacer packers. Packers should provide a free space between the glass and the groove to equalize the steam pressure and condensate drainage. It is not allowed for the glass to touch the aluminium profile. Packer width should be min. 2mm wider than the width of the glass, length 80-100mm. No more than two packers should be installed on each side of the glass panel. The distance of the packer from the corner of the glass package is 50-80 mm, for glass wider than 1.5 m - up to 150 mm.
If the building walls where the curtain wall are installed are plastered and painted after installation, aluminium profiles and glass (especially anodized aluminium profiles that can be permanently damaged by the plaster) should be protected from damage during plastering. As soon as the danger of damage to the profile from mortar and painting works ceases, protective tapes to be removed.
It is not allowed to hang any elements on the elements of the curtain wall (such as canopies, advertisements, lamps, etc.) unless it is foreseen by facade design (shop drawing).
Electrical wiring and other specialist cables should be routed around and away from the curtain wall and not through the frames. If this is not possible then it must be agreed by the contractor and supervisor as to an alternative solution and if required a specialist service provider brought in to assist with the routing of the cables.
The minimum temperature at the time of installation of facade elements should be + 5ºC.
4. Supervision and measurement of works
Before installing curtain wall elements, visually check that the elements are undamaged, including the glass, especially the sealant at the edges of the glass panes.
After installing the vertical and horizontal aluminium profiles, the contractor is obliged to check the geometry and verticality of the facade in the presence of the supervisor.
All executed works should be regularly checked before they are covered and checklists should be kept regularly. Inspections should be performed and the checklists signed by the responsible person of the contractor, previously appointed by the contractor. Supervision should be notified of each inspection at least one day in advance.
The contractor is obliged to ensure the inspection of the licensed instructor of the curtain wall manufacturer at least three times during the execution of works, in different phases of works, about which he will submit report. A supervisor should be invited to these inspections.
Unless otherwise stipulated in the contract, works are calculated per m2 of completed curtain wall. Installation of anchors is calculated 5% of the value of installed curtain wall. Installation of aluminium profiles - 45%, installation of glass - 35%, installation of flashing - 10% and completion of final works and cleaning of the facade - 5%.
January, 2021
Please note that the technical specifications on this web site are templates only, information provided should be carefully checked and aligned with your project needs.
At the time of writing this technical specification standard EN 13830 (2015) + A1 (2020) has not yet been harmonised and thus cannot be used for CE marking. Until harmonisation of this standard has been achieved, standard EN 13830 (2003) should be used.
The static design should take in account load from its own weight, wind loads, temperature expansion, the type of anchors and method of anchoring in structural elements made of concrete or other materials, the reaction of facade in an earthquake, etc.
For CE mark impact resistance class is determined internally (class I0 to I5) and externally (class E0 - E5).
Air permeability class is determined using the test pressure in [Pa] (there are classes A1, A2, A3, A4 and AE).
Watertightness class is determined using the test pressure in [Pa] (there are classes R4, R5, R6, R7 and RE).
Durability - the permanence of curtain walls cannot be tested and proved.
Ra value: The ability of transmitted daylight through the glazing to portray a variety of colors compared to those seen under daylight without the glazing. Scale is 1 - 100.
For instance, a low Ra value causes colours to appear washed out, while a high Ra causes colours to appear vibrant and natural.
In commercial glass, Ra indicates the effect the specific glass configuration has on the appearance of objects viewed through the glass.
For instance, a low Ra value causes colours to appear washed out, while a high Ra causes colours to appear vibrant and natural.
In commercial glass, Ra indicates the effect the specific glass configuration has on the appearance of objects viewed through the glass.
The warranty period for this type of work should not be less than 10 years.