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Keystone Hi Therm + Cavity Wall Lintels - Standard/ Heavy/ Extra Heavy Duty

Verified by manufacturer 3 months ago

Keystone Lintels Ltd Third party certifications:
  • BBA Agrément Certificate

    BBA Agrément Certificate

    Certificate type

  • BS EN 1090-1

    BS EN 1090-1

    Certificate type

  • ISO 9001 Quality Management

    Certificate type

Cavity >90 mm | BBA | Part L Compliant | UKCA | CE | Galvanized & Stainless

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Application

  • Hi Therm + lintels for use in an external cavity wall construction to support walls, floors and roofs above window and door openings.
  • Cavity widths greater than 90 mm.
  • Lintels should be installed with a minimum end bearing of 150 mm, bedded on mortar and levelled along its length and across its width.
  • The masonry above the lintel should be built in accordance with BS EN 1996-2.
  • Raise the inner and outer leaves simultaneously to avoid excessive eccentricity of loading, with a maximum height difference of 225 mm (masonry should be laid on a mortar bed and all perpendicular joints should be filled).
  • Allow the mortar to cure before applying floor or roof loads (temporary propping beneath a steel lintel is practiced to facilitate speed of construction).
  • NHBC & LABC recommend a damp proof course (DPC) or cavity tray should be installed over all openings in external cavity walls.
  • When installing concrete floor units or other heavy components above a lintel, care should be taken to avoid shock loading and floor units should not be dragged into position. Masonry immediately above the lintel should be allowed to cure.
  • Point loads should not be applied directly onto lintel flanges. Lintels should have a minimum of 150 mm masonry between the flange and the application level of any form of loading. Consult Keystone’s Technical Department if applying a point load above a lintel.
  • The external lintel flange must project beyond the window/door frame and it is recommended that a flexible sealing compound is used between the underside of the lintel flange and the frame.
  • Do not cut lintels to length or modify them in any way without consulting a Keystone engineer.
  • Lintel should be centred in the cavity and the distance between lintel up-stand and masonry must not exceed 10 mm.
  • Masonry should not overhang any flange by more than 25 mm.
  • The practice of propping a lintel is sometimes used to facilitate speed of construction. It should only be introduced after initial masonry load has been applied to the lintel.
  • Stop ends are required at each end of a lintel to prevent moisture cascading over the ends into the cavity and onto the inside wall.
  • At least two weep vents are required per opening and positioned not more than 450 mm apart.

Description

All Keystone Hi Therm + lintels satisfy the thermal performance requirements of Approved Document L of the Building Regulations (E & W), Northern Ireland’s Technical Booklet F and Scotland’s Technical Handbook, section 6. The Keystone patented rigid polymer thermal isolator acts as a thermal break, preventing thermal bridging while adding extra rigidity. Keystone lintels are insulated with expanded CFC-free profiled polystyrene insulation conforming to BS EN 13163. Provide a damp proof course / cavity tray over all lintels. For more detailed information applicable to a particular wall construction, contact Keystone Lintels Technical Department.


Refer to manufacturers literature for details regarding lintel ranges, height, thickness and Uniformly Distributed Load (UDL) figures.


Performance:

Fire:

  • Keystone Hi Therm + lintels have been subjected to a fire test (Report No. 380220) in accordance with BS EN 1363-1, at Exova Warrington Fire and achieved a one hour fire performance.

Corrosion:

  • Keystone’s Hi Therm + range of lintels are manufactured from high quality grade pre-galvanized mild steel to BS EN 10346 DX51D with a zinc coating of 600 g/m² (including both sides) conforming to BS EN 845-2.
  • The use of austenitic stainless steel is ideal when the life expectancy and maintenance programme of a building are key considerations. 
  • Material / coating specification in buildings exceeding three storeys in a non-aggressive environment should be limited to austenitic stainless steel (chrome nickel alloys). 
  • Material / coating specification for buildings in an aggressive environment (e.g. coastal sites) should be limited to austenitic stainless steel (molybdenum chrome nickel alloys). 

Structural:

  • The Keystone lintel range has safe working loads as detailed in each applicable loading table in the Keystone Steel Lintel Manual.
  • The structural performance figures within each table have been ascertained by testing in accordance with the requirements of standards BS EN 5977-2, BS EN 846-9 and BS EN 845-2.

Certification:

  • BBA Agrement certificate 18/5499 including regular assessment of production.
  • UKCA Assessment of performance, System 3.
  • CE Assessment of performance, System 3.
  • EN 1090-2 Execution Class 2, Declaration method 1,2,3a & 3b, Certificate 14/F106 & 14/F107
  • ISO 9001 Quality Management Systems, Certificate 18/Q059.
  • ISO 14001 Environmental Management Systems, Certificate 18/E019.

Special lintels:

Keystone lintels can be supplied to suit a wide range of wall types, loading scenarios and bespoke custom made specials:

  • Bay lintels (square or splayed),
  • Corner lintels,
  • Sunlounge lintels.
  • Eaves lintels.

Contact Keystone Lintels Technical Department for further information.

Stainless steel:

  • All Keystone’s Hi Therm + range of lintels can be manufactured from austenitic stainless steel, grade 304 2b BS EN 10088-Part 2 Astm 240 (European Grade 1.4307). 
  • Upon request, other grades of stainless steel lintels are available conforming to BS EN 845-2.

Additional features:

  • Free scheduling and specification service.
  • Keystone Hi Therm + lintels have a service life commensurate with that of the building in which they are installed.
  • Keying options to suit required plastering applications.
  • Eaves lintel.
  • Cant brick.
  • Powder coating.
  • Soffit cladding.
  • Brick slip cladding.
  • Universal arch.
  • Weep holes.
  • Stop ends.

Contact Keystone Lintels Technical Department for further information

General information

Color

Silver

Finish

Galvanized

Powder-coated

Material

Steel

Guidance for specification option:

  • Pre-galvanized mild steel to BS EN 10346 DX51D with a zinc coating of 600 g/m² (including both sides). Material Coating Ref L14.

Stainless steel

Guidance for specification option:

  • Austenitic stainless steel, grade 304 2b BS EN 10088-Part 2 Astm 240 (European Grade 1.4307) Material Coating Ref L3.
  • Austenitic stainless steel, grade 316 2b BS EN 10088-Part 2 Astm 316/316L (European Grade 1.4404) Material Coating Ref L1.

Length

-

Manufacturer guidance

Refer to Keystone Steel Lintel Manual or contact Keystone Lintels Technical Department.

Uniclass

Pr_20_85_48_11 Carbon steel lintelsPrimary
Pr_20_85_48_84 Stainless steel lintels

CAWS

F30/85 Prefabricated steel lintels

F30/755 Prefabricated steel lintels

Specification data - Carbon steel lintels

Standard

To BS EN 845-2.

Guidance for specification option:

UKCA and CE Marked to BS EN 845-2 Specification for ancillary components for masonry Part 2:Lintels.

Manufacturer guidance

Declaration of Performance certificates are available at: www.keystonelintels.com.

Lintel type

Composite.

Material finish and coating reference

Pre-galvanized mild steel to BS EN 10346 DX51D with a zinc coating of 600 g/m² (including both sides). Material Coating Ref L14.

Austenitic stainless steel, grade 304 2b BS EN 10088-Part 2 Astm 240 (European Grade 1.4307). Material Coating Ref L3.

Austenitic stainless steel, grade 316 2b BS EN 10088-Part 2 Astm 316/316L (European Grade 1.4404). Material Coating Ref L1.

Sizes

As Lintels schedule.

Characteristics

-

Resistance to fire

Has achieved a minimum period of 60 minutes in accordance with BS 476-20.

Thermal conductivity

Part L compliant.

Duty

Standard duty.

Heavy duty.

Extra heavy duty.

Accessories

Not required.

Keying options to suit required plastering applications.

Eaves lintel.

Cant brick.

Powder coating.

Show more

Sustainability data

Recyclability

100% Recyclable

Recycled content

As defined in clause 7.8 of BS EN ISO 14021

-

Manufacturer guidance

Ranging between 15–25 %.

Third party certifications

BBA Agrément Certificate

BBA Agrément Certificate

BBA - 18/5499 | Keystone Hi-Therm+

BBA Agrément Certificate

BBA Agrément Certificate

BBA - 98/3493 | Keystone Steel Lintels

BS EN 1090-1

BS EN 1090-1

EN 1090-1 | Cookstown

BS EN 1090-1

BS EN 1090-1

EN 1090-1 | Swadlincote

ISO 9001 Quality Management

ISO 9001 Quality Management

ISO 9001

Literature

NCCTL Non-Combustible Cavity Tray Lintel

NCCTL Non-Combustible Cavity Tray Lintel

Keystone Lintels Steel Lintel Manual

Keystone Lintels Steel Lintel Manual

Case studies

Church Farm Barns - Brick Slip Feature Lintels

Church Farm Barns - Brick Slip Feature Lintels

Borth - Bow Lintels

Borth - Bow Lintels

Disraeli Park - Bespoke Brick Feature Splayed Bay System

Disraeli Park - Bespoke Brick Feature Splayed Bay System

Station Approach - Brick Slip Feature Lintels

Station Approach - Brick Slip Feature Lintels