Profile selection

Once the choice of pre-finished steel and cladding system is made, the next consideration is the profile of the pre-finished steel roof and wall cladding. This will be influenced by requirements for both functional and aesthetic performance, with the latter generally taking precedent when considering walls. The system manufacturers offer many different and unique profiles which demonstrate particular features and attributes and can therefore be categorised by profile shape.

The illustrations included within the profile categories are intended to give an indication of the appearance that various types of profiles will offer when used on a building. They also illustrate and suggest the effects which can be achieved when shadows are cast across the face of the profile. The shadow effect will change depending upon the orientation of the profile in relation to the sun and will constantly change throughout the day and from dawn until dusk.

The broad range of profiles available can be used to provide a traditional appearance to the building or to present a modern experience with distinctive lines. In many cases, the systems can be used in imaginative ways to emphasise a particular style or feature or to change the overall scale and volume of a structure.

A careful choice of profile from the Cladding System Selector, together with the creative use of colour, taken from the Colorcoat® Product Selector, can ensure that each building demonstrates a distinctive and unique style.

This profile is the most widely used and is specified for roof and wall cladding applications. The trapezoidal or square box-like profile has distinctive angular ridges and valleys. The shape has been developed over many years and it offers good structural strength and spanning capacity. The trapezoidal profile comes in a wide range of depths and their individual crosssectional shape is unique to the system manufacturer. This usually means that profiles from different system manufacturers cannot be interchanged and lapped. The profiles are produced in a range of widths, with the most popular cover-width being 1000 mm.

Individual profiles are usually provided in both roof and wall variants. The roof profile is produced with the narrow flange of the colour surface to the external side. This allows rainwater to travel down the wide trough and into the gutter. Wall profiles are typically produced with the wide flange to the exterior, although the previously-described roof profiles can be used for this application. Trapezoidal profiles can be factory curved to form ridge, eaves or corner details or incorporated into flowing lines across the face of the building. In most cases, the curves are formed with the introduction of transverse ridges across the width of the profile.

Profiles within this type are produced from a series of interconnecting arcs and can easily be curved in the factory without the introduction of transverse ribs. Sinusoidal profiles were once regarded as the industry standard but have reduced in popularity in recent years and been superseded by trapezoidal profiles. Although traditionally used for roofs, sinusoidal profiles can also be used for wall applications.

Standing-seam profiles are specific for roof applications and are generally produced in a range of narrow cover widths. They are suited to very lowpitched roof applications (4° or less) and incorporate up-stands at each edge of the profile, which are spaced apart by a flat, semi flat or stiffened pan. The profiles emulate the cross-sectional shape traditionally adopted for lead and copper roof coverings. They have no through-fixings but are attached to the substructure by a series of mechanically-fixed clips or halters which are incorporated into the edge detail. The edge detail stands proud of the plane of the roof and is achieved through a clipping action or mechanical jointing. Mechanised jointing is done on site with the aid of a forming tool. Profiles in this category are either supplied to site or rolled on site in long lengths which are capable of running from ridge to eaves and spanning the full width of a curved roof.

Concealed fix profiles are similar to standing-seams in that they do not rely on an exposed through-fastener to fix the sheet to the substructure. The main difference is in the cross-sectional shape of the profile and the type of clip and position of the fastener which is used to attach the profile to the purlins and sheeting rails.

In many cases, the profile is attached to the structure by a spring clip, which engages into the female form of the profile up-stand. The clip usually extends across the width of the profile and engages in more than one flute or rib. The profile can be produced in long lengths and is suited to very low-pitched roof applications (4^o or less).

Shadow or trace profiles are widely used in composite panel systems for wall applications. Fixings can either be exposed or secreted within the joint of the panels, the latter giving a smooth appearance to a façade. The term covers a range of shallow profiles known as micro-rib, mini-rib, wave, tongue and groove and very often includes profiles approaching flat. This array of light profiles can be broadly classified as being based around ribbed or low-profile box shapes. The profile does not offer a major contribution towards the strength of the panel, but it does provide an enhanced visual effect.

This category contains a selection of profiles which do not conform to the normal cross-sectional shapes offered by traditional profiles. The feature profiles offer aesthetic appeal on façades and can be further classified as half-round, saw-tooth, plank or ship-lap styles.This category contains a selection of profiles which do not conform to the normal cross-sectional shapes

Many composite, façade and rainscreen systems use flat panels to enhance the aesthetics of a wall. Flat panels generally have finite dimensions in both axes and give a grid-like appearance to the façade through the use of recessed or highlighted joints. They are often available in curved options to match specific requirements.

These replicate the shape of traditional tile products, but have the advantage of being lightweight and can be laid more quickly than traditional tiles. Tile profiles can be incorporated into the external face of insulated composite panels, or alternatively they can be installed using traditional felt and batten techniques over conventional substructures or light gauge steel trays.

Liner sheets are produced as shallow or semi-flat profiles and sometimes include feature grooves. The profiles are designed to form the internal surface of a cladding system. Structurally, they are capable of supporting the weight of quilt insulation. Alternatively, they are incorporated into a composite panel as the internal surface. The liner sheet can provide a smooth and clean line to the internal face of the building. Liner sheets have traditionally been light gauge typically 0.4 mm. However, due to recent changes in Regulations relating to the specification and use of non-fragile products, there has been a move towards thicker gauge material on roofs.

Liner trays are different in concept to liner panels, as the trays are structural and formed from relatively thick gauge material. The edges of the tray, which are spaced apart by a flat or stiffened pan, are formed into deep webs and incorporate a top flange for the attachment of the external profile. The shape of the tray can retain quilt or board insulation within the void between the internal and external sheets faces and the edge up-stands. The trays span between the primary structure in roof or wall application and eliminate the need for secondary light gauge beams.