Roof insulation is instrumental in creating a sealed home envelope which will help your home retain heat in the winter and keep its cool in the warmer summer months. When working in conjunction with your ventilation system, insulation can save you fistfuls of money in utilities costs. When choosing the right insulation for your roof or loft, ensure that you consult your HVAC installer. It’s imperative that your insulation and ventilation systems work in unison to ensure the most efficient heating and cooling for your home.
Fiberglass
This comes in two varieties, the first of which is a blanket or quilt insulation roll of varying thicknesses. Usually manufactured from rock fiber or glass, this mineral wool is the standard material for use in empty lofts, or between stud walls and under timber floors.
The second option combines the fibers with an adhesive and is blown into place. The adhesive can contain harmful chemicals including formaldehyde. Advances in the industry have combined two different curly fibers which bond naturally, negating the need for adhesives.
Pros
- Easy to install and requires no special training.
- You can opt for recycled glass or sheep’s wool which are more environmentally friendly.
- It is easy to insulate small or large spaces.
Cons
- Protective clothing and safety equipment is required during installation as small fibers can irritate the skin, throat, eyes and lungs.
- If the loft or roof is inadequately sealed, the insulation will come loose.
- Over time, poorly installed fiberglass can sag, creating air pockets allowing drafts to enter your home.
Sheet loft insulation
Sheet insulation is utilized on the sloping sides of your roof. The firm boards are made from a variety of materials and come with optional fire-retardant, moisture-resistant or decorative finishes. Insulation can be expedited by having the boards cut to size prior to installation.
Pros
- Materials include cork, straw and wood board which make for more environmentally friendly options.
- Expanded polystyrene boards offer a higher R-value and are non-porous which eliminates the need for house wrap.
- If you opt for unfinished boards, they can be covered with plasterboard.
- High insulating R-value per unit thickness.
- Some boards come with their own attachment mechanisms making for much easier installs.
- Uncoated EPS sheet insulation can be recycled which makes them more eco-friendly.
Cons
- Sheet insulation can be more expensive, especially if cut to size by the manufacturer or when decorative finishes are applied.
- It has a higher carbon footprint than other insulation options.
Blown fiber insulation
Blown fiber insulation must be installed by a professional using specialized equipment and safety gear. Here insulation is blow-in into the gaps between joists.
Pros
- Professional installers will work very quickly.
- You can choose from a number of different insulation materials including greener options like recycled paper or wool.
- Ideal insulation for difficult-to-reach areas.
Cons
- The need for special training and equipment means that this form of insulation is more expensive to install.
- The insulation will become detached in lofts which are drafty or insufficiently sealed.
- Improperly blown fiber can either settle below the joists or, if not enough is blown, thermal bridging can occur along the joists. Ensure all joists are submerged with fiber insulation.
Spray foam insulation
Spray insulation utilizes chemicals which are created from foaming agents and polymers. During application the foam expands to almost 100 times its original size and then dries as a mass of polymer bubbles.
Pros
- Spray foam expands into every nook and cranny to give one of the most reliably sealed insulations available.
- Its excellent sealing qualities reduce moisture and mildew in the home.
- It prevents insect infestations.
Cons
- Professional installers need specialized equipment and safety gear which makes this type of insulation more expensive.
- Its eco-friendly as it saves on electricity, but the off-gassing of VOCs will compromise the indoor air quality for weeks after installation. Toxic fumes are also released by the foam when it comes into contact with fire.
Natural alternatives
Sheep’s wool has one of the highest R-values in the roof insulation business. Devoid of harmful chemicals, sheep’s wool is a great, if somewhat expensive alternative.
Cellulose fiber insulation is created from recycled paper. In addition to its positive impact on the environment, it’s also cheap and easy to install.
Soya fiber, cotton, hemp fibers, denim and straw are natural and environmentally friendly options.
Most home constructed prior to the 70’s are likely to have inadequate roof insulation. If you are unsure about the efficacy of your insulation, conduct a home energy audit. This will provide you with invaluable information on how to improve the energy efficiency of your home. The government also provides a grant incentive to reduce costs of home energy audits for the home owner.