Isover Spacesaver Plus

Spacesaver Plus is a glass mineral wool roll for loft applications with improved thermal performance. The rolls are pre-perforated to fit between common joist spacing at ceiling level. Other products within the range include Spacesaver, Spacesaver Ready-Cut and Spacesaver Lite.

Spacesaver Plus can also be considered for use between the joists in suspended timber ground floors and flat roofs.

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Product Features

  • Glass mineral wool rolls pre-perforated to 3 x 386mm and 2 x 580mm widths
  • Manufactured from up to 82% recycled glass
  • Achieves Eurofins Gold certification, the highest accreditation for indoor air quality

Fire Classification

Euroclass A1 Reaction to Fire classification according to EN 13501-1.

Product Specification

Thickness (mm) Length (m) Width* (m) λD Declared thermal conductivity (W/m.K) RD Declared thermal resistance (m².K/W)
100 7.00 1.16 0.040 2.50
150 4.67 1.16 0.040 3.75
200 3.50 1.16 0.040 5.00

*Pre-perforated to 3 x 386mm and 2 x 580mm widths

Product Benefits

  • Thermal Performance - Thermal conductivity of 0.040 W/m.K. Helps to reduce heat loss within the building envelope and decrease energy costs.
  • Easy to Install - Rolls are pre-perforated to 3 x 386 and 2 x 580mm to fit common joist spacing, or can be used full width for quick coverage.
  • Fire Classification - Achieves a Euroclass A1 Reaction to Fire classification, according to EN 13501-1. 
  • Sustainability - Manufactured from up to 82% recycled glass on a plant that uses 100% renewable electricity. For further details visit

Key Considerations

When using Isover Spacesaver Plus, you need to satisfy yourself that use of the product meets all relevant national Building Regulations and guidance as well as local, national and other applicable standards relevant for your construction or application, including requirements in relation to fire and applicable height restrictions.

Please refer to the following product documents: