Windpost buyers Guide


In this windpost buyers guide we hope to provide information to assist with the ordering and acquisition of ACS Windposts and various options available.

Typical windpost types

C type windposts are installed within a cavity, leaving the blockwork undisturbed. They are commonly used in masonry panels that are subject to lower wind loadings.

L type windposts are a cost-effective structural system, designed for use where high wind loadings may occur and in some cases where cavity widths restrict the use of C type windposts.

Mild Steel Windposts

In addition to the range of stainless steel windposts available, ACS also manufactures a full range of mild steel windposts. These are supplied in a variety of finishes to suit the customers requirements and specification.

A full range of section sizes are available to choose from including:

Circular Hollow Section (CHS)
Spine Section
Parallel Flange Channel Section (PFC)
Rolled Steel Angle (RSA)
Square/Rectangular Hollow Section (SHS/RHS)


Normally windposts are manufactured using grade S275 in either cold or hot finished mild steel, however, if other grades are required ACS has access to a wide range of materials and grades, and will manufacture to your requirements.


Mild steel components may be finished in a number of ways to suit the requirements of the client. The following details the typical finishes, however, please contact ACS for specific requirements.

  • Painted with zinc phosphate primer (note: components will be shot blasted to SA 2.5 prior to painting unless specified otherwise)
  • Galvanised (note: components will be acid dipped prior to galvanising and a minimum coating of 86 microns applied to BS EN ISO: 1461: 1999)
  • Factory finished
  • Bituminous painted (note: components may be supplied pre-painted with the required fire protection, however, ACS recommends components are painted on site as the finish is susceptible to damage in transit.

Special Windposts

ACS also offers a selection of posts to support spandrel panels and parapets. They are designed as cantilevers but require a much larger base connection than simply supported beams to resist bending movements.

Please contact the ACS technical department for further details.

Ties & Fixings

Windposts are supplied complete with ACS masonry ties and bolt fixings and are available in a range of configurations to suit individual requirements. The method of fixing the top and bottom connections is usually determined by the structure to which the post is fixed. The top connection is usually designed to provide vertical adjustment to allow for any site tolerances and differential movement that may occur in the structure.

Fixing Kits

To simplify the installation of posts, ACS has created a series of kits that come complete with all necessary drill bits, fixing bolts & washers etc to suit a variety of connections. All kits come complete with site installation notes that clearly show the fixer bolt types, tightening torques, curing times etc.


Windposts are predominantly manufactured from grade 304 stainless steel, however, they may be manufactured from other materials and be supplied in a number of finishes.


Windpost sizes may or may not be known depending on the status of the project.

The tables shown for the L & C type windposts detail typical section sizes to aid design. However, to ensure the most economical section is specified please liaise with a member of the technical department or alternatively please supply the following information;

  • Wall construction (internal and external masonry thicknesses and cavity size)
  • Masonry panel width (dimension of load that is to be applied to windpost)
  • Masonry panel height
  • Wind loading per m?

This will allow a basic design to be carried out. However, for special posts such as parapet posts please consult ACS Stainless.

How to order

When ordering windposts please supply the following.

Section size
Overall opening height
Base fixing (e.g. Concrete / Steel / Timber)
Top fixing (e.g. Concrete / Steel / Timber)
Wall construction (internal and external masonry thicknesses and cavity size)
Material & finish (Stainless / Mild Steel)


Article originally published on 16th October 2018