There are several types of insulation materials that can be used for attics, each with its own advantages and disadvantages. Here are some of the most commonly recommended types of attic insulation:

1. Fiberglass batt insulation: This is the most common type of attic insulation and is made of glass fibers that are formed into batts. It is relatively inexpensive and easy to install, making it a popular choice for DIY projects. However, it can be less effective at insulating than other materials and can be a skin irritant if not handled properly.

2. Spray foam insulation: This type of insulation is considered to be the gold standard for attic insulation by many builders. It offers a higher R-value than other materials and is incredibly energy efficient. However, it is more expensive than other types of insulation and must be installed by a professional.

3. Cellulose insulation: This insulation is made of recycled paper and has an R-value of approximately 3.2 to 3.7 per inch. It is considered an eco-friendly insulator, but it can be a potential fire hazard and may not mix well with liquid.

4. Loose-fill fiberglass insulation: This insulation is blown into the attic using an insulation blower. It is considered one of the best types of insulation for attics and walls, but it can be more expensive than other types of insulation.

When deciding which type of insulation to use, it is important to consider factors such as R-value, ease of installation, and environmental impact. It is also important to ensure that the insulation is installed properly to maximize its effectiveness.