# Wall & Roof Insulation — PIR, Rock Wool and Envelope Panels

> Wall and roof insulation for industrial and commercial envelopes is commonly installed as PIR or rock wool panels. PIR gives better thermal performance per millimetre, while rock wool is mineral and non-combustible and is used where fire performance governs; on low-rise buildings the roof usually carries the larger share of heat gain.

## What we deliver

**Imported high-performance wall and roof insulation** — PIR panels, rock wool
panels and insulated envelope systems for industrial, warehouse and commercial
buildings, installed as part of the facade package rather than as a separate
trade.

Insulation is the least visible part of an envelope and one of the largest
levers on running cost. It is also where ECBC compliance is most cheaply
recovered when the glazing specification cannot be improved further.

## Facade leadership experience

Our Director – Facade, Akhilesh Kumar Singh (25+ years in facade engineering),
has led delivery on projects including:

| Project | Location | Scope | Quantity |
| --- | --- | --- | --- |
| Anygraphics Factory | Noida, Uttar Pradesh | PIR panel, rock wool panel, semi-unitised structural glazing | 6,500 sq. m. |

## How the materials compare

| | PIR panel | Rock wool panel |
| --- | --- | --- |
| Thermal performance | Higher per mm | Lower per mm |
| Fire behaviour | Combustible core, rated systems available | Mineral, non-combustible |
| Thickness for a given U-value | Thinner | Thicker |
| Acoustic performance | Moderate | Better |
| Typical use | General envelope area, tight build-ups | Fire-critical zones, compartment lines |
| Relative cost | Comparable, varies by grade | Comparable, varies by grade |

## What drives the cost

Target U-value under ECBC for the climate zone · core material and fire grade ·
panel thickness · whether the roof is new-build or overlay · span and support
spacing · sheet profile and finish · junction and flashing complexity.

## Where projects go wrong

- **Insulating the walls and neglecting the roof.** On low-rise industrial
  buildings the roof usually carries the larger share of the heat gain.
- **Ignoring the fire grade in a ventilated cavity.** Combustible insulation
  behind a combustible panel with a continuous cavity is the assembly that has
  caused the worst facade fires.
- **Thermal bridging at fixings and brackets.** Continuous metal through the
  insulation can undo a significant share of the specified performance.
- **Poor junction detailing.** Corners, parapets, penetrations and eaves are
  where insulation continuity is broken, and where condensation appears.

## Why Hagerstone

**Envelope treated as one system.** Insulation, cavity, membrane, sub-frame and
outer skin detailed together by the same in-house facade team that delivers the
cladding and glazing.

**Industrial experience** — delivered on live factory and warehouse envelopes
alongside structural glazing, where sequencing around production matters as much
as the specification.

**100% in-house execution**, ISO 9001 / 14001 / 45001, 79+ quality checkpoints.

## Standards referenced

Opaque assembly U-value targets by climate zone under **ECBC 2017**. Fire and
life safety for external wall assemblies under **NBC 2016, Part 4**. Core
reaction-to-fire classification expressed to **EN 13501-1**.

## Frequently asked questions

### PIR or rock wool — which should we use?

PIR gives better thermal performance per millimetre, so it wins where space is tight or the U-value target is demanding. Rock wool is mineral and non-combustible, so it wins wherever fire performance governs — high-occupancy buildings, compartment lines, and anywhere an insurer takes a view. Many industrial envelopes use both: PIR across the general area, rock wool at fire-critical zones.

### Does the roof matter as much as the walls?

In India it usually matters more. A flat or low-pitch roof takes the highest solar incidence of any surface on the building for most of the day. On single-storey industrial and warehouse buildings the roof frequently dominates the cooling load, and it is the cheapest surface to improve because it is accessible and repetitive.

### Can insulation be upgraded on an existing building?

Roofs, often yes — overlay systems can be installed without disturbing the occupied space below. Walls are harder, because the insulation sits behind the cladding, so it usually only makes sense when the facade is being replaced anyway. If a re-clad is planned, that is the moment to fix the envelope.

## Sources

- [ECBC 2017](https://beeindia.gov.in/) — Building envelope — opaque assembly U-value
- [NBC 2016, Part 4](https://www.bis.gov.in/standards/national-building-code/?lang=en) — Fire and life safety
- [EN 13501-1](https://standards.cencenelec.eu/ords/f?p=CEN:105) — Reaction to fire classification

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Source: https://hagerstone.com/services/facade-glazing/wall-and-roof-insulation