Le faire soi-même ou engager un pro

Determine Where You Need Insulation & How Much

If your home needs more insulation, you may want to do it yourself (DIY). Depending on where you want to add insulation and your comfort level with completing the project, installation could be a weekend DIY project.

Before you start or make any decisions, you should determine where you need insulation and how much of it you need to install. To determine how much insulation you already have, check to see if your batt insulation is labelled with an R-value or calculate your R-value with a simple formula.

Should You Do It Yourself?

It depends. Consider the following:

  • Is the space you want to insulate open and accessible? This would include unfinished attics and basements, not walls or ceilings, unless a renovation is ongoing that allows access.
  • What type of material do you want to use? Batts or rolls can be installed by homeowners, while other types of insulation generally require professionals (though blown insulation equipment can be available for rental).
  • What is your level of comfort and your skills for taking on the job?
  • Are there any safety issues present which might make the job more suitable for a professional?

Safety Considerations:

The easiest and most common places to do a DIY insulation project are in unfinished attics and  basements. However, before you make the final decision and start installing insulation yourself, you should inspect the area. A professional should be called in to correct problems and complete the insulation job if you find any of these conditions or issues (visit ENERGY STAR®’s guide to insulation projects  for more information):

  • Wet or damp insulation indicating leaks
  • Mouldy or rotted attic rafters or floor joists indicating moisture problems
  • Kitchen, bathroom, and clothes dryer vents that exhaust moist air directly into the attic space instead of outdoors
  • A history of ice dams in the winter (an indication of serious air leaks and insulation problems)
  • Little or no attic exhaust ventilation
  • Knob and tube wiring (pre-1930), which can be a fire hazard when in contact with insulation
  • If you have many unsealed and uninsulated recessed “can” lights, special care must be taken when insulating around these fixtures
  • Possible presence of Asbestos

About Asbestos

Asbestos was once common in insulation products, but is no longer today. If your home was built before 1975, it is possible that the insulation is vermiculite, which can contain asbestos. Vermiculite is a lightweight, pea-size, flaky gray mineral. If you have reason to believe existing insulation may be vermiculite, do not disturb it and have it tested by a professional for asbestos. Your local health department, or possibly an insulation contractor, can help you identify means of getting this testing done. If it is determined that asbestos is present, a professional needs to remove the insulation.

Investing Your Time in the Job

With enough time and attention to detail, adding insulation in an attic is something most anyone can do. However, taking the time to inspect and possibly remove old insulation, find and seal all air leaks, and then properly install new insulation can be tedious.

Actual job times depend on the project, but generally installation is a full weekend project entailing:

  • Inspection
  • Identifying needs for materials
  • Purchase of supplies
  • Completing the labour

While the whole process may take time, the final step, completing the labour, may only take a few hours, depending on the size of the job. Plus, saving money on professional installation can make your time worth it.

Considering Costs

There is obviously a significant cost difference between hiring a professional and doing it yourself. Costs vary significantly by size of the home, location, and accessibility of added insulation, etc., but you can expect the cost of a professional job to be two or three times more than just the cost of the materials you’d need to do it yourself—if you purchased fiberglass, mineral wool, or slag wool insulation. For other product types, professional installation can run ever higher. There is no DIY spray foam insulation option for re-insulating an attic, and professional installation can require you to vacate your home for up to 24 hours due to dangerous compounds released during both the installation and curing processes.