Product Information

Wall Construction
Timber Frame
Outer Leaf
Inner Leaf
Wall Width
Loading Conditions


Product Code Standard Length (mm) SWL (kN) Weight (kg) Nominal Height (mm)
CTF70750 750 5 2.51 145
CTF70900 900 5 3.02 145
CTF71050 1050 5 3.52 145
CTF71200 1200 5 4.02 145
CTF71350 1350 5 4.52 145
CTF71500 1500 5 5.03 145
CTF71650 1650 7 4.02 145
CTF71800 1800 7 7.54 145
CTF71950 1950 7 9.18 187
CTF72100 2100 7 9.89 187
CTF72250 2250 7 10.60 187
CTF72400 2400 7 11.30 187
CTF72550 2550 9 18.67 261
CTF72700 2700 9 19.76 261
CTF72850 2850 9 20.86 261
CTF73000 3000 9 21.96 261
CTF73300 3300 9 24.16 261
CTF73600 3600 9 26.35 261
CTF73900 3900 10 35.41 261
CTF74200 4200 10 38.14 261
CTF74575 4575 10 41.54 261
CTF74800 4800 10 43.58 261
  • The SWL (safe working load) is based on the total UDL (uniform distributed load) over maximum span using 150mm end bearings.
  • Standard lengths are available in increments of 150mm at lengths up to 3000mm, 300mm at lengths from 3000mm - 4800mm (including 4575 but excluding 4500mm).
  • CTF lintels should be suitably propped and secured with provided restraint clips and timber batten (not provided) during construction.


Steel lintel for use in timber frame construction, consists of single element lintel, allows vertical differential movement of timber frame. Built in DPC thanks to Catnic's signature black powder coating
  • Duplex Corrosion Protection
  • Built-In DPC
  • Made in the UK for a lower carbon footprint and certified to BES 6001 Responsible Sourcing standard.
  • Made using lower carbon manufacturing
  • It is possible to reuse all of our lintels, providing that they are not damaged. Contact our technical team for more information
Catnic standard duty timber frame lintel for 70-85mm cavity wall shown in situ
  • Built-in Damp Proof Course (DPC) Profile

    Many Catnic lintels offer a unique profile shape that combine with the unique Duplex Corrosion Protection or stainless steel to create an effective barrier that acts as a built-in DPC, meaning any water penetrating into the cavity automatically transfers across the sloping face of the lintel and is disposed of externally.

  • Duplex Corrosion Protection

    A coating of thermal setting polyester powder is then applied by an electrostatic process, further protecting the lintel.

What our customers think

Video Guides

When selecting a lintel, there are three factors that should be considered to ensure the correct specification: the type of wall construction, the dimensions of the structural opening and the total load on the lintel. In this video, we run you through the lintel selection process.

Catnic thermally broken lintel installation

Once you have chosen the correct lintel for your project, it is crucial that the lintel be installed properly – if it is not, it could lead to serious issues for the building. In this video, we explain the installation considerations for cavity wall lintels.

Builder installed Catnic CG90/100 lintel

Catnic’s Thermally Broken Lintel is the only lintel on the market to provide a complete thermal break between the inner and outer leafs. In this video, we outline the key benefits of Thermally Broken Lintels and explain the installation process.

Catnic TS90/100 lifted into position by builders

Steel lintels, and specifically Catnic's thermally broken lintels, have a significant role to play in reducing thermal bridging and achieving carbon gains. They represent one of the simplest and most economical ways for building fabric to be designed and constructed to help achieve the carbon gains necessary to meet current and future building regulations.

Catnic balcony installation at kingsdown gate

Support & FAQs

Calculating the load imposed on lintels depends on a variety of factors, including the wall type in which the lintel is installed, and whether floor or roof loads need to be accounted for in addition to masonry loads. Lintels are primarily design to support uniformly distributed loads (UDLs) but on occasions point loads also need to be considered. This guide only provides an overview of how the loads on lintel are established and should not be used as a substitute for obtaining loading calculations either direct from the lintel manufacturer or from a qualified structural engineer.

Specifying Catnic’s Thermally Broken Lintels (TBLs) will significantly improve the thermal efficiency of a property and help ensure that the project’s necessary environmental credentials are met. Specifying Catnic TBLs can be done with ease as they have the same safe working loads as Catnic’s traditional lintels – meaning TBLs can be specified like for like. Catnic TBLs can also be used for standard duty, heavy duty and extra heavy use, making them suitable for a wide range of projects. You'll find our full range here

The correct specification of lintels is crucial, however it is just as important to ensure that each one is installed correctly. Here are five top tips to ensure an trouble free installation. To watch our video on installing cavity wall lintels click here

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