Mineral Wool Cavity Insulation

About

What is mineral wool cavity wall insulation? Mineral wool cavity insulation is a semi-rigid slab or batt that gets built into a masonry cavity wall while the wall is going up. It is spun into fibres either from recycled glass and sand (glass mineral wool) or from volcanic rock (stone wool), and it works by trapping still air in amongst those fibres so heat cannot cross the cavity easily. It is the most widely used cavity insulation material in the UK, and for good reason: it is non-combustible, it costs less per square metre than rigid board, and because it is soft and flexible it squashes neatly around wall ties instead of needing to be cut around them. One important distinction. This is the product you build into a new wall. It is not the blown or injected insulation that gets pumped into an existing, already-built cavity by drilling the outer leaf. That is a different job, it needs a PAS 2035 assessment and a TrustMark-registered installer, and it is not something you can buy supply-only. If your walls are already up, this range is not the right product for you. The benefits of mineral wool cavity insulation Non-combustible - Euroclass A1 to BS EN 13501-1, the highest reaction to fire classification there is, and a property of the slab itself rather than of the wall it sits in. Lower running costs - a continuous, tightly fitted layer across the cavity cuts the heat escaping through your walls and lets your heating work less hard. Fits around wall ties - the soft fibre structure lets the slab close around ties and irregularities, so you get fewer gaps than you would with a rigid board. No clips or discs on full fill - the slabs friction fit between the two leaves, which means less kit on site and a quicker build. Water repellent and breathable - manufactured with a water-repellent additive and non-hygroscopic, so the slab sheds water rather than soaking it up, while still letting water vapour pass through the wall. Useful acoustic performance - the density and fib