Matilda’s Blanket Internal Wall Insulation System is a dry lining system, comprising rigid polyisocyanurate (PIR) boards with a composite foil facing on both sides bonded to Rigidur H gypsum fibreboard on one side and Glasroc Multiboard F on the other. The system is for use as an insulating dry lining to masonry walls in existing and new domestic and non-domestic buildings. The system is supplied in ‘50mm’ and ‘25mm’ varieties, this refers to the nominal insulation thickness used.

Typically, panels measure 570mm wide and span from floor to ceiling which keeps the panel weight suitable for manual handling. Panels are available with the nominal characteristics shown in Table 1. PIR Insulation thickness are dependent on existing wall thickness and required final U-values.

Nominal Characteristics

Essential Characteristics


Panel lamination involves materials being coated with adhesive and laminated to create a blanket. The blanket is then cut to size and the relevant tongue-and-grooves are cut-in using dedicated machines. Dampers and base track are installed. Exposed cut ends of panels are foil coated.
Panels and ancillary components along with installation drawings, which cross reference panel numbers, are delivered to site.


Backed by a 25 year guarantee, covering material and installation quality.

Behaviour in relation to Fire

The reaction to fire classification according to I.S. EN 13501-1:2007+A1:2009 for the gypsum fibreboard faced system is B1- s1, d0. It has been recently downgraded from an A2 rating due to universal downgrading of PIR containing products.

The Matilda’s Blanket Internal Wall Insulation System has not been considered or assessed as possessing any contributing fire resistance to the external wall of the building. The existing wall structure must possess the full fire resistance properties required in Part B of the building regulations for each building. When properly installed, the insulation is contained between the two plasterboards; the insulation, therefore, will not contribute to the development of a fire or present a smoke or toxic hazard as the fire develops.

Typical U-Values on Existing Dwellings