Time to insulate

Home cooling accounts for a significant portion of electricity costs for any home in Cayman, which is why our utility bills seem to double over the summer months. However, having a home that is properly insulated can make a big difference to your electricity expenses.

Although energy efficiency should, ideally, be part of the home’s original design and construction, a lot that can be done to existing properties to improve their energy efficiency and cut down on utility costs.

Attic insulation
The first place to look for insulation in your home is in the attic. Approximately 65 per cent of the effect of home insulation can be obtained through insulation in the roof, versus 20 to 25 per cent from the windows and doors, and the remaining 10 to 15 per cent from the walls.

An attic offers a large selection of insulation options, due to the abundance of space. However, at the same time, the collection of joists can make it a difficult area to properly fill, which should be kept in mind when deciding on which type of insulation to use.

The most basic of insulations, these rolls of fibreglass, cotton or mineral wool are easy to use but quite difficult to fit. As it can be tricky to cut the rolls to the correct size and fit them perfectly in the space, gaps can easily occur, which can severely degrade the effectiveness of the insulation.

Blow in
Composed of loose fibres of either fibreglass or cellulose blown into an open area, this insulation can conform to irregular spaces, thereby avoiding the pitfalls created by less flexible forms such as rolls. However, due to its loose nature, blow in materials do not offer the insulation value per inch, which means that a deep layer may be required before reaching the desired insulation values. This makes blow in insulation suitable only for areas where a depth of around 16 inches or more would be possible.

Spray foam
The newest type of insulation, spray foam is applied to the inside of the roof, rather than to the floor of the attic. The foam expands rapidly when applied, creating an even layer of insulation that can conform to any shape, thus providing a effective barrier. The foam also offers a high insulation value per inch. Spray foam should only be used on attics that are not vented, resulting in the attic itself being cooler as well the home beneath it.

Windows and doors
The second most important element of home insulation is the windows and doors. Double-glazed windows have increased in prevalence over the last few years to the point where the less efficient single-glazed windows are becoming rare. However, the efficiency of double-glazed windows can be improved by injecting an inert gas, such as argon, in the gap between the panes, as this reduces the heat transmission even further.

The frame material of the window can also have an impact, with vinyl windows providing reduced thermal transmission when compared to aluminium windows.

Doors can also improve the home’s insulation. Both the glass in the door and the material of the door itself can make a difference to the temperature of your home. Double-glazed glass is available for doors and when it comes to materials, fibreglass outperforms wood and steel.

Remarkably, the walls of the home play a relatively minor role in the overall insulation. However, that is not to say that the walls should be forgotten, either during the construction process or when installing insulation retroactively.

Insulated concrete form integrates the foam insulation into the construction process for a greater impact. The poured concrete that is used to fill the forms not only creates a strong wall, but is unlikely to leave gaps through which warm air could seep into the home.

Existing walls or block construction can also be insulated using rigid foam panels, with the use of foam on the outside of the wall reducing thermal bridging to the interior of the home. To finish the foam, a fibreglass mesh is placed over the insulation before it is plastered.

When planning to retrofit foam panels to an existing home, keep in mind that the materials and labour required for finishing the panels could have a significant impact on the overall cost of installing the insulation.

Another option is to use rolled insulation or spray foam insulation inside walls. For most types of insulation this would need to be done before the drywall is fitted, although spray foam insulation can be applied through a hole cut in the drywall, allowing application after the construction has been completed, if necessary. However, there are different types of spray foam insulation for wall use and ceiling use; the type intended for use inside existing walls expands more slowly and less forcefully to stop the chance of popping the drywall off the studs.

Insulation is an ideal tool to keep your home cool during the searing heat and combat the rising cost of electricity. Regardless of which insulation you choose to install, the benefits will far outweigh the initial outlay, resulting in a home that is both comfortable and energy efficient.