There are basically 4 different types of insulation available.
Matting – This is sometimes called blanket or quilt insulation. It is available as rolls in different thickness. The usual type is made of mineral wool. This is the usual type and is used to insulate roofs, stud walls and suspended ceilings. You do need to wear protective clothing such as gloves and mask when installing this material.
Loose-fill material. This is made of from cork granules, vermiculite, mineral wool or cellulose fibre. The usual method of installing this is to pour it between the ceiling joists to the required depth.
Blown insulation. This is made of fire-resistant cellulose fibre. This is the most green form of insulation as it is made from recycled newspapers. It must beinstalled though by professionals as it requires professional equipment to blow the material into difficult to reach places.
Rigid insulation boards. These can be used to insulate walls, floors and ceilings. They are made from plastic such as polystyrene, polyurethane (PUR) or polyisocyanurate (PIR). Thes come as boards and so has to be cut to fit. Thisis very effective as insulation and is often used in walls. To find the best insulation for you, look for the Energy Saving Trust Recommended logo. Insulation products which carry the logo have met strict criteria, which are set by an independent panel and reviewed each year.

How much insulation to use
With insulation, more is always better. The thicker the insulation is the less heat you will lose and the more money you will save. However, not all insulation is the same as some is more effective than others. The insulation potential of a product will be listed on the packaging. This is quoted as th K-value or Lambda. The lower the value, the better the material at insulating.