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Brickwork/Blockwork Fixing Accessories

• Introduction
• Lintels - stainless steel or galvanised steel?
• Wall ties - for steel framing systems

Introduction

• This page provides guidance on components, including wall ties and lintels, specified in NBS Section F30 - Accessories/ Sundry items for Brick/ Block/ Stone walling - particularly clauses F30/210 to 291, and F30/755.

Lintels - stainless steel or galvanised steel?

Introduction

• For years there has been an assumption, by many architects, that stainless steel should always be specified in preference to galvanised steel for these components. Conversely the housebuilding industry, dealing mainly with low-rise construction, has generally used galvanised steel in preference to stainless steel.
• These assumptions are now being questioned, particularly for lintels, in highly cost-conscious projects such as those built using PFI methods of procurement.

Legislation - England and Wales

Remember that following the Approved Documents is the easiest way to comply with the Building Regulations, but it is not the only way - see Use of Guidance.

• Approved Document A : The key legislative document referring to the selection of materials for brickwork and blockwork accessories is Approved Document A.
• Clause 1.4 - Structural work of masonry (Page 7) : References British Standard BS 5628-3.

British Standards

Remember that compliance with British Standards is not mandatory unless invoked by legislation. In this case BS 5628-3 is invoked by Approved Document A (see above).

• BS 5628-3:2001/2005 : Code of practice for the use of masonry - Part 3: Material and components, design and workmanship.
• Clause 4.5 - Metal support and restraint components (Page 11) : Invokes BS EN 845-1, 2 and 3 and refers to Table 1 for the selection of materials.
• Table 1 - Selection of ancillary components in relation to material/ coating specification and situation (Page 12) : Note that the materials listed in the Table are only relevant for buildings up to three storeys in a non-aggressive environment. Above three storeys it is necessary to refer to Note 1; in an aggressive environment it is necessary to refer to Note 2.
• Table 1 / Note 1 - States "In contact with or embedded in an outer leaf ..., in buildings exceeding three storeys in a non aggressive environment, the material/coating specifications should be limited to austenitic stainless steels ..."
• Clause 4.11 - Lintels : Invokes BS EN 845-2, referring just to "pressed steel" and therefore allowing any type of pressed steel (galvanised or stainless) complying with the standard.
• BS EN 845-2:2003 : Specification of ancillary components for masonry - Part 2: Lintels.
• Annex C.1 - Steel lintels (Page 27) : Invokes Table C.1 which lists just one option for stainless steels - Austenitic stainless steel (chrome nickel alloys) to EN 10088. This table also defines the Material Coating Reference L3 as referred to in BS 5628-3, Table 1.

Guidance

• Lintels to BS EN 845-2, constructed of austenitic stainless steel (chrome nickel alloys) to EN 10088, must be specified for buildings over three storeys.
• Zinc coating and galvanizing (which is a method of zinc coating) are not acceptable.

Wall ties - for steel framing systems

• Specifiers should be aware that there are now wall tie systems specifically intended for use with Light Steel Framing Systems. These are generally vertical channels, screw-fixed through the insulation boards into the steel studs, with sliding slot ties built into the bed joints of the brickwork. The channels perform the dual function of providing restraint to the wall ties and holding the insulation in place.
• Examples include:
• Ancon 25/14 Restraint System - Download brochure and refer to Page 9 of 28.
• Halfen 25/17 HH channel - Download brochure and refer to Page 21 of 40.

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