Curtain wall repair and refurbishment
Curtain walls are built to outlast most of their parts. The aluminium frame can serve for more than 60 years, but double glazed units, gaskets and sealants wear out much sooner, and that is when leaks, misted glass and draughts start.
Repair ranges from tracing one leak and replacing a few glass units to reglazing a whole elevation, overcladding it, or taking it out and starting again.
Guide price: £51,067 to £161,481 for recent public replacement contracts
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Signs the facade needs attention
- Water stains on ceilings or floors near the glazing after heavy rain.
- Misting or condensation between the panes of a sealed unit.
- Gaskets that have shrunk, cracked or come out of the frame.
- Chalky, faded or peeling powder coating on frames and caps.
- Draughts, whistling or rattling in strong wind.
- Cracked glass, or a pane that has broken without any obvious impact.
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What repair and replacement cost
| Item | Typical figure, ex VAT |
|---|---|
| Replace curtain walling to a link corridor in two places Rotherham Metropolitan Borough Council, June 2022, awarded value | £51,067 |
| Replace a defective curtain wall screen and windows at a school Westmorland and Furness Council, July 2024, awarded value | £159,531 |
| Replace windows and curtain walling at a school Cumbria County Council, July 2022, awarded value | £161,481 |
| New stick curtain walling, for full replacement Supply and install, before removal of the old wall and access | £450 to £525 per m² |
Where these figures come from
Per m² rates are for a proprietary aluminium system on a flat elevation, supply and install, excluding VAT, from the RIBA Journal cost guide by Gleeds (March 2025). They do not include scaffolding or access, preliminaries, design fees or testing. Public contract figures are the awarded value on each Contracts Finder notice and cover the whole package described. Small repairs such as replacing a glass unit or a run of gaskets are priced per visit and depend heavily on access: a ground-floor pane needs a tower, a high one may need a cherry picker, cradle or abseil team.
Chasing a leak or a facade at the end of its life? Tell us about the building and we will look for a repair specialist.
Get matched3
How long the parts last
These are typical service lives from whole-life costing research on aluminium curtain walling. Exposure, quality and maintenance change them.
Typical service lives
A major refurbishment, replacing glass units, gaskets and capping, is typically due every 25 to 35 years.
| Part | Typical life | What fails |
|---|---|---|
| Aluminium frame | Over 60 years | Rarely fails; finish wears first |
| Glass | Over 60 years | Breakage rather than age |
| Double glazed units | About 25 years | Edge seal fails, unit mists |
| EPDM gaskets | 15 to 30 years | Shrink, harden or work loose |
| Silicone sealant | 5 to 20 years | Loses adhesion, cracks |
| Polyester powder coating | 15 to 25 years before recoating | Chalks and fades |
| Anodised finish | 30 years or more | Pitting in polluted or coastal air |
Tracing leaks
A good investigation starts inside, mapping where water appears and when, then tests suspected joints from outside with a hose or spray bar, working upwards from the lowest point so one test does not hide another. Water often travels along transoms and appears well away from the joint that let it in.
Repair, reglaze, overclad or replace
If the frames are sound, replacing glass units and gaskets can give a facade decades more life and a better U-value. Overcladding places new capping or a new outer skin over the old frames. Full replacement makes sense when the frame itself is failing, when thermal performance is far below today's standards, or when the building is being comprehensively refurbished. Replacement curtain walling counts as building work and has to meet current Building Regulations.
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How a repair job gets done
Inspect
Leak history and defects are logged, and joints and seals inspected from inside and out.
Test
Suspect joints are water tested to find the actual entry points.
Propose
A repair, reglaze, overclad or replace option is priced with access and programme.
Repair and retest
Work is done with the building occupied where possible, then the repaired areas are tested again.
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Questions people ask
Why is my curtain wall leaking?
The usual causes are failed gaskets or sealant, blocked drainage paths in the transoms, poorly sealed joints between mullions and transoms, and badly detailed interfaces with the roof or floor. Water testing finds the actual entry point.
Can you replace one glass unit in a curtain wall?
Usually, yes. In a capped stick system, the cap and pressure plate are removed on that pane only. Bonded and some unitised systems take more work, and high panes need suitable access.
How long does curtain walling last?
The aluminium frame can last more than 60 years. Glass units last about 25 years and gaskets 15 to 30, so a major refurbishment is typically due every 25 to 35 years.
How much does curtain wall repair cost?
Small repairs are priced per visit and depend on access. Recent public contracts to replace curtain walling at schools and a council link corridor were awarded at £51,067 to £161,481.
Is it better to refurbish or replace curtain walling?
Refurbish when the frames are sound and the problem is glass, gaskets or finish. Replace when the frames are failing, the thermal performance is very poor, or the building is being overhauled anyway.
Find a curtain wall repair specialist
Location first, then the package, then your contact details. Each step is short.
We are an introduction service, not a curtain walling contractor. We look for one that covers the project and name them to you first; nothing is passed on until you agree.
Thanks, we have your enquiry.
- We look for a curtain walling contractor that covers the project and handles this kind of package.
- When we find one, we email or call to tell you who they are. Your details reach that firm only if you say yes.
- They review the drawings or the building and price the work. No marketing from us.