Roof insulation is now required by law in new buildings as part of the South African government’s energy efficiency initiative. Whether it’s compulsory or not, insulating your roof is a great idea. Good insulation will keep your home cozier all year round and help reduce your energy costs.
Types of Roof Insulation
There are various types of roof insulation, including:
- Reflective foil: A commonly used type of roof insulation, typically installed under the roof to reflect heat away from the house interior.
- Glass wool (fibreglass): A popular insulating material for years, usually installed in the ceiling cavity.
- Natural sheep’s wool: The original roof insulation remains a popular choice.
- Polyester: An increasingly popular option, an “itch-free” alternative to glass wool, often made from up to 85% recycled polyester.
- Stone wool (sometimes called rock wool): Made from volcanic rock, it has excellent acoustic and thermal insulating properties and is highly fire resistant.
Reflective foil differs from other insulating materials. The small pockets of air in bulk insulation provide a barrier that prevents heat or cold from escaping or entering the roof, while reflective foil simply reflects heat or cold away from the area.
How Much Does Roof Insulation Cost?
The cost of roof insulation and roof repair depends on the materials used and whether special equipment or expertise is needed for installation. For example:
- Reflective sarking: One of the least expensive types of insulation, around R1980 for a 60m x 1350mm roll.
- Reflective foil with an extra “air cell” barrier: Provides greater thermal insulation that adheres to BCA 6 Star energy efficiency guidelines, costing about R2750 for a 22.5m x 1350mm roll (approximately 30 sq.m).
- Glass wool batts without foil backing: Around R990 per 9 square meter pack.
- Polyester batts without foil backing: Often cost about 50% more than glass wool batts.
When comparing the prices of various types of insulation, carefully consider their R-value (a measure of thermal efficiency). It might be worth investing a bit more in a product with a higher R-value.
Installing roof insulation is a hot, unpleasant, and uncomfortable task. Get quotes from roof insulation suppliers and installers before deciding to tackle the task yourself. Installers’ rates start at about R352 per hour. They often get insulation at a discount and pass the savings on to customers, working quickly and efficiently. You’ll likely be surprised by how affordable it can be to have it installed by professionals from GP Roof Repairs.
