Insulating Rafters In Your Attic

Your home's attic is an untapped resource for living space. If you were to clear out the decades of accumulated odds and ends that will never be used again and hold a garage sale, lo and behold, you would find another bedroom or a space for the kids to play video games or do their homework. Insulating rafters in your attic is essential because it is the room most exposed to the hot and cold temperatures of the environment outside.

Insulating rafters is a job you can do yourself but one of the most important considerations is to ensure that you observe the R value that exists in the area in which you live. The R value is the barometer for the kind and thickness of insulation you are required by law to use in your home.

Attics featuring exposed rafters

Installing insulation in an attic with exposed rafters is not possible in an existing house because the roof space is extremely limited and cannot be accessed after construction. If, however, your attic is an afterthought as an addition to your home, while it is being built, insulating rafters can be done before completion.

If your attic has exposed rafters, you will need to purchase insulation products that have a higher R value per unit thickness because of the limited space available in the ceiling.

Batten height of 100 to 125mm is required to avoid compression of bulk insulation. Due to these considerations, you should consider insulation materials that provide the same R value but with less thickness, such as polystyrene boards. Because of the poor capacity for ventilation in the roof space, condensation is more of an issue in ceilings with exposed rafters. A vapor barrier should be installed directly above the lining of the ceiling.

Attics with concealed rafters

Insulating rafters is far more straightforward in attics where the rafters are concealed. Bulk insulation can be installed between the rafters and you can avoid moisture issues by placing a vapor barrier above the lining of the ceiling.

Insulating rafters should be done by a professional who has all the correct tools for the job and can guarantee an excellent result. Unless you are experienced in this kind of work, you may find it is extremely laborious and uncomfortable working in a confined space, exposed to the heat of the day.

Some insulating materials such as fiberglass batts can be hazardous to health if not handled properly. Installing insulation over fire blocking, wires or pipes needs to be done carefully so as not to obstruct the element or conceal it from view in the future.

See Also:

Choosing a FIberglass Insulation Type
Attic Radiant Barriers