Façade defects · Cladding
Corroded brackets and fixings: causes, risks and repair.
How the brackets, rails and anchors behind cladding and stone corrode out of sight, why coastal and wet cavities are worst, and how they are inspected.
| At a glance | |
|---|---|
| What it is | Corrosion of the rails, brackets, anchors and screws that hold cladding, stone or screens to the building. |
| Main risk | Panels or stone pieces coming away, with no warning from the front of the façade. |
| Common on | Rainscreen façades, stone-faced buildings and coastal or exposed sites. |
| Usually spotted by | Intrusive investigations and condition surveys. |
Why fixings matter
Every panel and stone on a façade depends on a few small fixings. They sit in the cavity, where they are often wet and never seen. When they corrode, the façade can look sound right up until a panel slips.
How to recognise it
- Rust staining running from panel joints.
- Sagging, misaligned or loose panels.
- Cracked stone along the line of hidden fixings.
- White powdery corrosion on aluminium next to steel.
Why it happens
- Mild or galvanised steel used in a wet cavity.
- Aluminium and steel in contact without isolation.
- Salt-laden air on coastal sites, such as Portsmouth and the south coast.
- Trapped water from blocked drainage or failed trays.
Why it matters
- Safety. A failed fixing can let a panel or stone fall.
- Hidden extent. One corroded fixing usually means others.
- Cost. Replacement means removing the cladding, so finding it early matters.
How we investigate it
We open up the cladding at representative locations to inspect brackets, rails and anchors directly, identify the metals used and record corrosion. Fixing types, depths and connection details are measured on site rather than taken from records. Where needed, a specialist carries out anchor pull-out tests.
How it is put right
- Replace corroded fixings with stainless steel or compatible aluminium.
- Isolate dissimilar metals.
- Improve drainage and ventilation in the cavity.
- Increase inspection frequency on exposed elevations.
From our investigations
Examples from our own work. Client and building details are withheld.
See our published case studies
What to send us
The address, the building's age and location, photos of any staining or loose panels, and any previous reports. Email enquiries@mtconsult.co.uk, use our contact form or call 0800 048 5229. We typically respond within one working day.
Frequently asked questions
Can you see fixings without removing cladding?
Rarely. Targeted openings, or a borescope through joints, are needed to see them.
Are coastal buildings more at risk?
Yes. Salt in the air speeds up corrosion, especially of steel and of dissimilar metals in contact.
Is stainless steel always the answer?
Usually, but the grade must suit the exposure, and it must be isolated from other metals.
Related
Talk to us
Worried about what's holding your cladding?
Our in-house contracting team provides the access and opening-up, so you have one point of contact.