Blown In Insulation Vs Spray Foam

There are various methods of insulating your house among which blown in and spray foam techniques are more common and known to be effective. So the following is a list of their various key features along with strengths and drawbacks to help you better understand which method will benefit you.

 Blown in insulation

  • The insulating material (usually fiberglass and cellulose) is blown in smaller chunks with the help of a machine and a large hose going into the attic.
  • Both the chief insulating substances – fiberglass and cellulose – have about the same R-values of around 3-4 per inch.
  • Blown in insulation doesn’t leave as much gap as batt insulation does.
  • Both fiberglass and cellulose do not have a good R-value like spray foam. Their R-values are around 2.2 to 3 per inch.
  • Cellulose is a very environmentally friendly material because it is made from recycled paper and it is more cost-effective than other substances like cotton and safer to install than fiberglass.
  • The installation is majorly not a DIY project and requires professional expertise.
  • Prolonged exposure to moisture can lead to decaying of the insulation material and growth of mold. The insulation isn’t for a lifetime and generally lasts for about 10-25 years.

 Spray foam insulation 

  • The foam (usually polyurethane) is sprayed to fill cracks and gaps in the attic to form a hermetically sealed barrier.
  • Spray foam provides the highest R-value – while open cell spray foam has about an R-value of 2.2 to 3.5 per inch, closed cell spray foam has about 6-7 per inch.
  • Spray foam expands to become 10 times its previous size thereby filling up most unfillable nooks and crannies of your house.
  • Open cell spray foam has a much higher R-value of around 3.5 per inch while closed cell has 6-7 per inch.
  • Open cell spray foam is ineffective against penetration by water vapor but closed cell provides a good barrier against the entrance of moisture and prevents growth of mold and mildew. But when installed incorrectly spray foam is known to cause minor health hazards especially breathing troubles and may even give off a fishy smell.
  • The installation procedure requires experienced contractors.
  • Closed cell spray foam can last for up to 80 years given that the installation is done properly. Spray foam insulation also allows you to move the envelope of your building from the floor to the roof and lets you include ducts and air vents within the envelope without requiring you to change the scheme and system of your house.