The benefits of alignment washers 05 February 2020

The Hubble telescope is best known for the beautiful images it collects of space. However the first images it took were fuzzy - a 2.2 micron misalignment in the telescope’s main mirror was all it took to wreck the image quality. While a slightly larger figure, a 15mm misalignment in a curtain wall bracket can also jeopardise the success of project continuity, reducing the risk of construction downtime. Here Steve Parkes, key account manager at fastening and fixing supplier TFC Ltd, explains how to overcome alignment challenges when installing a curtain wall.

Curtain walls took their name from medieval castle infrastructure. While the phrase initially referred to a defensive wall between two towers, it has now come to mean a non structural covering for a building, such as glass panels. Today, the market is booming - growing at a compound annual growth rate (CAGR) of 9.3% and is expected to reach GB£42 billion by 2025, according to Grand View Research.

Alignment challenges
During the installation of a curtain wall, it’s vitally important that fixing brackets are correctly aligned when fixing to the building structure. If not, it will result in time delays possible penalties associated with the contract. If, unfortunately, there is alignment issues then options are limited. Fixing brackets can be modified and/or the anchor positions can be redrilled to compensate. Both of these solutions are very time-consuming and therefore by default, expensive. Thankfully there is another way - the alignment washer, a fast, simple low cost alternative offering a flexible on-site fixing solution.

The alignment washer, with its oversized or slotted holes, gives the installer that extra leeway to line up the bracket and anchor location and tighten down before locking off. When the contractor is happy all the elements have been checked for position, the washer is injected with a high strength, rapid setting construction resin – TFC has found in all tests that fischer FISV360S resin performs perfectly in these conditions.

The alignment washer offers several clever design features to allow the resin to completely fill any voids remaining after alignment, in fact it works so well the product can be used upside down and even under water. The joints are now permanently locked in their correct position. So efficient is the locking off process we have a number of customers who use this method to lock off their brackets regardless of any alignment issues.

Types of alignment washer
There are two fundamental types of this technology, circular and rectangular. Rectangular washers are designed for use with cast in channels and with their slotted hole give ± 25mm adjustment in one direction. Circular washers can be used in a variety of applications such as stick curtain walling, balustrades and balconies. Circular washers offer a ±15mm adjustment in either direction. Both circular and rectangular washers are available to suit M10, 12, 16 and M20 bolts or anchors and are hot dip galvanised for long-term corrosion protection.

Alignment washers have been specified on numerous prestigious sites across the UK, including hospitals, convention centres, apartments, offices, universities and Government buildings. If a designer, project manager, architect or structural engineer specifies the alignment washer from an early stage, they can be confident that there will be no alignment problems and downtime later down the line.

A 2.2 micron misalignment was all it took for the Hubble telescope’s images to be blurry and a small misalignment can lead to big losses in a construction project.

TFC is a European fastener supplier, with 1,000s of threaded, panel and moulded fasteners, wave springs and Spirolox retaining rings in stock, TFC’s dedicated product specialists and supply chain assist service offer complete tailored fastening solutions, from design to procurement.

Claire Aldridge Deputy Editor t: +44 (0) 1727 814 450

Having joined the magazine in 2012, Claire developed her knowledge of the industry through the numerous company visits, exhibitions and conferences she attended both in the UK and abroad.

Claire prides herself on keeping readers well informed and up to date with the latest industry news.