How Does Foil Insulation Work?
Sisalation, and other types of foil insulation are extremely effective in reducing the transfer of heat. This helps keep you warmer in winter and cooler in summer. While bulk insulation works by slowing the heat transfer through the insulating material, foil insulation like Sisalation use their reflective surface to stop radiant heat.
Contrary to what you might expect, insulation foil doesn't need to face its reflective foil surface outwards 'towards the sun' in order to work, and in fact (for safety/anti-glare reasons), it is much more commonly installed with the reflective surface facing into the house. When used in combination with bulk thermal insulation, Sisalation foil insulation is very effective both in increasing the thermal efficiency of the building, as a windbreak, and also can serve as a reassuring guarantee that the thermal wall batts won't come into contact with the brickwork. Without an air-gap of about 2cm, foil insulation won't work as it should, and with no air-gap, the product is basically ineffective as an insulator.
Fletcher's Sisalation foil wraps come in 30m and 60m rolls, and when installed with an airgap, achieve an approximate R1.0 value. Some of our other popular foil insulation products include Knauf Earthwool Foil Faced Roofing Blanket and Kingspan Air-Cell Insulation.
Types of Aluminum Foil Insulation
Reflective Foil Insulation
Reflective foil insulation and breather wall wrap products provide a secondary protective skin for your home which can reduce draughts and help make you home more comfortable. Sisalation protects the building structure from the elements prior to the application of the external cladding and acts as a secondary protective layer against rain and dust after the construction has been completed. Roof sarking is also known to be used under older roofs, as a kind of insurance against leaks. While this may 'do the job' it is of course not the recommended solution to a damaged or leaking roof. Foil insulation can provide an additional R-value when installed within an air cavity in the building frame.
Roof Sarking and Foil Wrap
Roof sarking is installed in homes to reduce summer heat gains and reduce cooling costs. Aluminium foil insulation is a highly reflective material that rebounds radiant heat rather than absorbing it. Reflective insulation together with thermal insulation batts are a perfect combination to optimize your homes R-value. Our preferred brand of foil wrap reflective insulation is Sisalation® by Fletcher. Sarking insulation for roofs can also assist in condensation control from water dripping down from the underside of metal roof sheets, and down into the ceiling area below. This is particularly a concern in tropical regions where condensation and humidity is likely to be an issue.
Breather Wall Wrap
Where air transfer from each side of the membrane is required and unclassified water barrier properties are acceptable, breather wall wrap products are considered to be the best option. Homes in cooler climates with a high insulation value run the risk of condensation problems in the construction. Breather insulation foils allow the construction to breath allowing possible condensation to escape and dry up. Contact us for advice regarding breather wall wrap products and their application.