Absorbing Sound with Acoustic Mineral Wool Slabs

Slabs of mineral wool aren’t especially designed for insulation. They’re used primarily to absorb sound, and are especially effective when used in conjunction with other acoustic materials and can cut out most of the sounds. Mineral wool slabs are used in cavities-they can be put in walls, ceilings, and between floors. They’re manufactured to give the maximum possible sound absorption of sound by being very dense.


Mineral wool is primarily made of silicon oxide, which is blended with metallic oxides. It offers many advantages in a building beyond its sound absorption qualities. As it’s rot proof, it will be hard for any fungi or mold to grow in the wool. The slabs of mineral wool work well in sustainable buildings, being made in part from recycled materials, and also gives fire insulation as well as some thermal insulation.

The use of mineral wool has expanded greatly in recent years as people have become convinced by its efficacy. As it’s twice as dense as most insulation, it kills sound very effectively. Additionally it doesn’t react with most materials, making it suitable for use in most buildings.

In Floors

When using mineral wool slabs in floors, it will be most effective if the mineral wool is cut slightly thinner than the joists, and if the slabs are laid end to end, with no gaps between them. When the floorboards are down, they should be covered with insulated mats to give almost complete sound insulation. To fit the floorboards in place, use screws or angular ring nails; these will help stop sound and vibrations.

In Walls and Ceilings

Mineral wool in walls should be placed between the studs, and you should pack in as many layers as feasible without them having to be pressed down-the same applies to ceilings. To keep it in place, use resilient bars on the studs before hanging drywall over the top. This will completely fill the space and almost completely deaden the sound between rooms.


You’ll often need to cut the mineral wool slabs to fit an area. This can be done with a utility knife or other sharp knife. Be aware, however, that the nature of the material means that the edge of the blade will be blunted very quickly, so either have a number of blades to hand or be prepared to sharpen often.

It’s best if the mineral wool isn’t a tight fit between joints or studs. The best sound insulation comes from a slightly looser fit. In a ceiling, a good aerosol contact adhesive is useful for making the layers stay in place initially.


The nature of garages means that you’re not going to achieve complete soundproofing. But using mineral wool slabs will help cut down on the sound, especially when used with acoustic membrane and acoustic plasterboard. With a combination of those you could create a space where a band could comfortably practice. The use of several different materials can block much of the sound, especially from the neighbors.