You may be asking yourself, why use mineral wool insulation as opposed to other less irritant materials?
The answer is simple, cost and fire safety.

 Mineral wool insulation i.e Rockwool or Glasswool can be factory manufactured and mass-produced fairly easily and inexpensively compared to alternatives, mineral wool can be made from sustainable and recyclable materials and is also extremely resistant to fire with a class 1 standard fire rating, fiberglass wool is an excellent soundproofer and ideal for using within the cavity of interior dry lined walls and ceilings.
Old existing insulation in your loft does not necessarily have to be removed prior to fitting new material unless it is heavily soiled or wet, new insulation can be overlaid on top of the existing material to provide extra thickness and can be tailored to a desired depth by choosing one of the various insulation thicknesses available. The thicker the depth of insulation then the more heat will be retained thus saving money on the heating bills.

 What is involved in the installation process, will I still be able to use my loft?

 The insulation material is laid in the gaps between the ceiling joists on top of the plasterboard ceiling, it can also be installed in the gaps between the roof joists below the roofing felt before being covered with plasterboard or firecheck board for example if the property is a dormer type loft.
After installation the insulation can be covered with a polythene membrane stapled to the roof joists, (Island Drainage provide this service as standard on loft installations - Jeffs idea!) to seal in any potential airborne fibres. Alternately timber flooring can be laid on top of installed insulation this has the added advantage of providing more storage space in your home.

ALL INSULATION MATERIALS USED BY ISLAND DRAINAGE ARE SOURCED FROM LOCAL SUPPLIERS WHEREVER POSSIBLE.