If I fully fill my masonry cavity wall with Rockwool Cavity (full fill) Batts, will I require additional fire stopping at the party wall junction?
No – In the opinion of the British Board of Agrément, Rockwool Cavity will satisfy the following requirements of the 2000 Building Regulations: B3 (4): Resistance to fire spread between and within cavities. Rockwool Cavity is non-combustible and therefore may be used in buildings of every purpose group. They may also be considered as a cavity barrier when tightly fitted between masonry leaves where an insulated wall connects with the cavity of a wall without cavity insulation.
