Facade Rain-Screen Ventilated Systems
A rainscreen, or ventilated facade, is a cladding assembly whose outer panel is a screen rather than a waterproof skin: a drained, ventilated cavity behind it carries away water that gets past, and the breather membrane on the backing wall is the actual weather line. Cavity barriers at every compartment line control fire spread through the continuous cavity.
By Dhruv Agarwal · · 2 min read
What we deliver
Imported ventilated envelope systems — the sub-frame, insulation, breather membrane, cavity barriers and outer panel installed as one designed assembly.
The system works on a principle that surprises people the first time they hear it: the outer skin is not waterproof and is not meant to be. It is a screen. The drained, ventilated cavity behind it is what manages the water that gets past.
Facade leadership experience
Our Director – Facade, Akhilesh Kumar Singh (25+ years in facade engineering), has led delivery on projects including:
| Project | Location | Scope | Quantity |
|---|---|---|---|
| DLF — WeWork | Cyber City, Gurgaon | Kingspan dry cladding ventilated system | 3,325 sq. m. |
The assembly, outside in
| Layer | Function |
|---|---|
| Outer panel | Sheds rain, handles UV, sets appearance |
| Cavity, 25-50mm | Drains and ventilates; open at bottom and top |
| Cavity barrier | Stops fire and smoke at every compartment line |
| Insulation | Thermal performance; mineral wool preferred |
| Breather membrane | The actual weather line — continuous and lapped |
| Sub-frame | Carries panel load to structure; thermally broken |
| Substrate | RCC, blockwork or sheathing board |
What drives the cost
Panel material — ACP, solid aluminium, HPL, terracotta, stone · cavity depth · extent of cavity barriers · insulation grade and thickness to meet ECBC · sub-frame complexity and bracket spacing · whether brackets are thermally broken · building height and access strategy.
Where projects go wrong
- Cavity barriers omitted or shortcut. The most serious failure mode available in this system.
- Membrane treated as secondary. A discontinuity at a corner, penetration or lap leaks regardless of panel quality.
- Ventilation path blocked. Insulation pushed into the cavity or sealed openings stop the airflow, and the cavity stops working.
- Thermal bridging ignored. Hundreds of brackets through the insulation can undo the assembly U-value the specification was written to achieve.
- Combustible insulation behind a combustible panel. Each may pass alone; together in a ventilated cavity they are a different proposition.
Why Hagerstone
One team detailing the whole assembly. Sub-frame, membrane, insulation, barriers and panel are designed together rather than split between a cladding supplier and a site contractor who meet only at the interface.
Imported systems within our in-house facade scope, alongside curtain wall, fenestration and cladding — so the junctions between systems are one party's responsibility.
79+ quality checkpoints, ISO 9001 / 14001 / 45001, 100% in-house execution.
Standards referenced
Fire and life safety, including cavity barrier requirements for external wall assemblies, under NBC 2016, Part 4. Opaque assembly U-value under ECBC 2017.
Standards referenced
- NBC 2016, Part 4 — Fire and life safety (Bureau of Indian Standards)
- ECBC 2017 — Building envelope — opaque assembly (Bureau of Energy Efficiency)
Frequently asked
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