Keystone Box Lintels - Standard/ Heavy/ Extra Heavy Duty

All Keystone box 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 box lintel has perforations along its length acting as a plaster key. Keystone box lintels can be insulated.

In external walls 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 lintels have been subjected to a fire test (WARRES No. 101263) in accordance with BS 476-20 and (Report No. 508704/R) in accordance with BS EN 1363-1 at Exova Warrington Fire and achieved a one hour fire performance.

Corrosion:

• Keystone’s box range of lintels are manufactured from high quality grade pre-galvanized mild steel to BS EN 10346 DX51D with a zinc coating 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 98/3493 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:

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

Contact Keystone Lintels Technical Department for further information.

Stainless steel:

• All Keystone’s 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 Steel lintels have a service life commensurate with that of the building in which they are installed.
• Feature plate.
• Powder coating.
• Soffit cladding.
• Brick slip cladding.
• Universal arch.
• Weep holes.
• Stop ends.
• Bespoke.

Contact Keystone Lintels Technical Department for further information