Risk matrix
How the four HSG264 scores combine into a single material risk band.
The material assessment algorithm in HSG264 combines product type, extent, surface treatment and damage into a score from 2 to 12. This matrix shows how those raw scores translate to the risk bands your management plan should act on.
Overview
Why this exists.
The material score is intentionally coarse — it is a triage tool for planning, not a scientific measure of exposure. Its job is to tell a duty holder which items need action first, and which can be left with a labelled inspection cycle.
Reading the matrix takes practice. A pipe insulation lagging with heavy damage will always land in the top band, no matter its extent. A cement soffit board scores low even when large in area. The matrix rewards this asymmetry — friability matters more than quantity.
The explainer
Material assessment matrix
| Material score (product + condition)↓ / →Priority score (location + use) | Low | Medium | High |
|---|---|---|---|
| 10–12 (severe) | Very highscore 12 Immediate isolation. Licensed removal. | Very highscore 12 Immediate isolation. Licensed removal. | Very highscore 12 Immediate isolation. Licensed removal. |
| 7–9 (moderate) | Highscore 9 Planned removal or encapsulation within 3 months. | Highscore 9 Planned removal or encapsulation within 6 months. | Very highscore 10 Fast-track licensed removal. |
| 4–6 (minor) | Mediumscore 5 Manage in place. Formal re-inspection every 6 months. | Mediumscore 6 Manage in place. Annual re-inspection. | Highscore 8 Encapsulate; re-inspect at 6 months. |
| 2–3 (intact) | Lowscore 3 Label, register, re-inspect annually. | Lowscore 4 Label, register, re-inspect annually. | Mediumscore 5 Label, brief occupants, re-inspect annually. |
How to read this
- Rows are the combined product + condition score (2 = intact cement, 12 = severely damaged lagging).
- Columns are the site-specific priority modifiers layered on top by the duty holder.
- Cell colour tells you the response band that HSG264 expects — from label & monitor to remove.
Key takeaways
Score ≥10 = act now
Anything scoring 10, 11 or 12 needs immediate protective action pending a licensed response.
Score 7–9 = plan
Formal work plan within 12 months, area labelled and access controlled.
Score ≤6 = manage in place
Label, register, re-inspect. Do not disturb. Most well-encapsulated cement products fall here.
FAQs
Common follow-up questions.
Where does the priority score come from?
It is calculated by the duty holder using the four-factor algorithm in HSG264 Appendix 2 — normal occupant activity, likelihood of disturbance, human exposure and maintenance activity.
Can I just use the material score?
No. The material score alone tells you how dangerous a material could be if disturbed. Without the priority score you have no idea how likely disturbance is.
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