R-Value

• The amount of thermal resistance an insulation material creates is known as its R-value. A higher R-value means the home insulation is more effective at stopping heat from passing through.
  
  

Fiberglass

• Fiberglass insulation is the fluffy, pink material used in most homes. The R-value of fiberglass insulation is usually 3 to 4 per square inch. Be careful when working with this type of insulation because the fiberglass can irritate the eyes, skin and lungs.
  
  

Rockwool

• Rockwool home insulation is available in dense sheets similar to the pink fiberglass type. The density makes rockwool a good option for soundproofing walls as well as insulating for heat. It has roughly the same R-value as fiberglass insulation.
  
  

Polystyrene Boards

• Polystyrene board home insulation has the highest R-value, usually around 4 to 5 per square inch. It is highly flammable and should be protected by another material that is fire-resistant.
  
  

Foam

• Polyurethane foam home insulation is sprayed directly onto the walls and under the roof. It should only be applied by a certified professional. Foam insulation has an R-value of approximately 4 per square inch.