New houses and buildings that are sustainable and that aim to be carbon neutral over the course of their useful life need to use materials that are as natural and ecofriendly as possible. Using synthetic insulation materials, which have a large manufacturing carbon footprint is no longer an option. Instead, new, natural materials are being used. Some of these offer the chance to use raw materials that might have otherwise been thrown away, or produced at a lower level, harming industry in the UK.
One of the major natural insulation materials, for example, is sheep’s wool. Sheep farmers in England, Scotland and Wales are now finding a new outlet for sheep wool, as demand for it from the textiles and clothing industry continues to decline in favour of cheap materials from abroad, and from synthetic textiles.
Advantages of Natural Materials for Insulation
Apart from the obvious fact that they are natural, produced from sheep bred primarily for food, and a good renewable raw materials, sheep’s wool also has remarkable insulation properties. Wool is more thermally efficient that synthetic materials such as mineral fibre, which has been used extensively for insulating lofts and walls.
Wool can absorb moisture and release it again while maintaining its efficiency as an insulator at exactly the same level. Natural materials such as hemp, which are derived from plants, use up carbon dioxide as they are grown, so acting as a carbon sink. Finally, after a long and useful life as insulation materials, wood and hemp and other natural products present no problem for disposal. They can simply be rotted down to form compost, or burnt as a fuel.
Types of Natural Insulation Materials
Sheep’s wool is becoming very popular as an insulator for lofts and walls. Black Mountain Sheep Wool is produced from Welsh sheep from the Black Mountains. It is prepared in rolls that are easy to lay between the rafters of a loft, and is priced competitively to offer a feasible alternative to synthetic materials for any home owner or builder. Many producers also make loft hatch insulation covers to complement their rolls of loft insulation, preventing heat from escaping from the house as much as possible.
Hemp is produced from fibres extracted from the hemp plant, which grows well in the UK’s temperate climate. Hemp insulation has a very good thermal efficiency and can be produced in rolls of bespoke widths, making it ideal for insulating lofts where the rafters are a non-standard distance apart.
Recycled Insulation Materials
Warmcel is a recycled insulation material that is made from recycled newspaper that is finely shredded and comes as a loose insulation material that is spread between the loft rafters rather than rolled out. It is a very good environmental product as it is better than carbon neutral – more carbon is absorbed than released over the life of the product.
For lofts where the insulation needs to be at the top between the roof struts – in an old house or a house that has is having a loft conversion, for example, a flexible insulation slab is available made from the residues produced by saw mills. This compressed wood insulation provides great insulation to prevent heat loss and it is also good for sound proofing.
Finally, eco-fibre is being made from recycled plastic bottles, bound together with polyester to replace glass fibre for insulation applications. Not only does it have very similar thermal properties, it produces none of the fine fibres that can be a hazard to the lungs. This is a particularly good recycled insulation material for cladding the inside of timber walls in new builds.