Recladding

Fibre Reinforced Facade Encyclopedia: Installation

Recladding is the replacement of an existing external facade skin with a new one, whether because the original is non-compliant, has failed, has reached the end of its service life or is being changed for appearance. It differs from new construction in one decisive way: the structure behind the facade already exists, it was designed for the cladding that was originally installed, and it cannot be redesigned. That constraint, not appearance and not cost per square metre, is usually what determines which materials are available to a recladding project.

At a glance

Why weight is the hard gate

When the building was designed, the slab edges, the brackets, the supporting frame and the fixings into the substrate were all sized for the dead load of the original cladding plus wind. If the original skin was a 4 mm aluminium composite panel at around 5.5 kg per square metre, the structure was never asked to carry anything heavier, and there is no reserve capacity waiting to be used. Replacing that skin with a system at 50 or 90 kg per square metre adds load at the slab edge, adds moment into the brackets, increases the tension on every anchor into the existing concrete, and in some cases changes the load path on the primary structure.

Upgrading the structure to accept a heavier facade is possible and is sometimes done, but it is expensive, intrusive and slow. It means opening up slab edges, adding steelwork, testing and often replacing anchors, and obtaining structural certification for altered elements, all on an occupied building. On most projects the sensible order of decisions is to establish the available weight budget first, then choose from the materials that fit inside it.

Establishing the weight budget

A structural assessment answers three questions. What was the original cladding, and what dead load did it impose? What capacity do the existing supporting elements actually have now, allowing for their condition, for corrosion of fixings and brackets, and for anything else that has been added to the facade since? And what does the current wind loading standard require, which may be more onerous than the standard in force when the building was designed?

That last point catches people out. A building designed decades ago may have been assessed against superseded wind provisions, so a facade replacement is often the first time the wall is checked against AS/NZS 1170.2 as it now stands. The suction cases at corners and parapets frequently govern, and they act on the fixings rather than on the panel.

Anchor capacity in the existing substrate is the other common surprise. Pull-out testing on representative anchors in the actual concrete, blockwork or steel, rather than reliance on published values, is the reliable way to establish what the fixings can carry.

Choosing the replacement system

• Weight, against the budget established by the structural assessment. This is the first filter and it eliminates most heavy options immediately
• Fire compliance, demonstrated for the specific product by test rather than assumed from the material category, and assembled as evidence for the building surveyor
• Depth and set-out, because the existing openings, slab edges and window interfaces are fixed and the new system has to land on them
• Substructure strategy, meaning whether the existing rails and brackets can be reused after inspection and certification, or whether a new substructure is needed and where it can be fixed
• Access and handling, since panels have to be brought in and placed from a swing stage, mast climber or scaffold on an occupied building, which favours panels a small team can handle
• Maintenance and service life, since the owner is unlikely to want to do this again

Fibre reinforced polymer and glass fibre reinforced concrete both sit in the usable weight range, with FRP the lighter of the two, and both can be moulded to reproduce a modelled or curved original facade rather than flattening it. Where the existing structure has genuine capacity, heavier systems come back into play, but that has to be demonstrated rather than hoped for.

Practical constraints beyond weight

Recladding is surgery on an occupied building. The new panel module has to reconcile with existing window positions and slab levels, which were set out for the original cladding and will not offer the tolerances a new build would. Window and balustrade interfaces, flashings and sealant joints usually have to be redesigned around what is found when the old skin comes off. Waterproofing behind the old cladding may be degraded and is often replaced as part of the works.

Programme and disruption matter more than on new work. The facade is opened in sections, made weathertight each shift, and the residents live with it, so panel handling weight, the number of fixings per panel and the tolerance for adjustment on site all have real value.

Standards and references

• AS/NZS 1170.1 permanent and imposed actions, and AS/NZS 1170.2 wind actions
• AS 3600 concrete structures and AS 5216, design of post-installed and cast-in fastenings in concrete
• AS 1530.1 combustibility, AS 5637.1 group number and AS 5113 full-scale facade testing
• NCC 2022 Volume One, Specification 7 and the external wall provisions (check the edition adopted in your jurisdiction)
• AS 4284, testing of building facades, where a performance mock-up is required for the new system
• AS 4654 and AS 3740, where waterproofing behind the facade is renewed as part of the works

Related terms

• Replacement and remediation
• Lightweight cladding
• Combustible cladding
• Dead load per square metre
• Substructure
• Aluminium composite panel (ACP)

Questions specifiers ask

Reviewed by Richard Halvorsen, General Manager, ShapeShift Technologies. Last updated September 2026.