UK · Updated 2026 · How-to
Surplus Rockwool & Mineral Wool for Energy Retrofit in Cambridge: 2026 Sourcing Guide
Cambridge retrofits — from PAS 2035 refurbs to EnerPHit self-builds — rely on high-spec materials at cost. Surplus and clearance stock delivers the same certified spec at 40–60% less. Here's the 2026 sourcing map for East of England.
Retrofit-relevant mineral wool sources
- Merchant clearance on certified stock
- Manufacturer over-orders (PIR, mineral wool, plasterboard)
- Cancelled project surplus in your postcode
- Regional trade Facebook groups
Certification you must preserve
- BBA certificate on insulation and boards
- Batch/lot number for U-value calculations
- Fire rating on partition materials
- Datasheets for PAS 2035 evidence packs
2026 Cambridge pricing
| Grade | Typical price | Notes |
|---|---|---|
| Job-lot / bulk | £12.00 per pack | Merchant clearance, palletised |
| Standard graded | £27 per pack | Sorted, ready-to-fit stock |
| Heritage / premium | £42 per pack | Character grade, hand-picked |
Collection and delivery inside Cambridge
Most Cambridge sellers hold stock inside CB1, CB2 and CB4 and offer East Anglia next-day pallet £52–£82. For loads over a tonne of mineral wool, a hiab drop is usually more economical than multiple van runs.
Frequently asked questions
+Does surplus mineral wool count for PAS 2035?
Yes when spec and certification are preserved. Keep batch numbers and BBA certificates with your evidence pack.
+Can mineral wool get wet?
Recovers if it dries fully within 48 hours. Prolonged saturation permanently reduces R-value.
+Can I use surplus on ECO4-funded work?
Yes — ECO4 assessors care about spec and installation quality, not new-vs-surplus provenance.