As a building materials and insulation expert with years of experience in the construction industry, I'm often asked about the correct installation of insulation materials like fiberglass. Fiberglass insulation is a popular choice due to its effectiveness in reducing heat transfer and its resistance to fire, insects, and mold. When it comes to the orientation of the insulation, there are a few key factors to consider.

Firstly, it's essential to understand the composition of fiberglass insulation. It typically consists of glass fibers that are bonded together with a resin. One side of the insulation has a paper facing, which is often coated with an asphalt adhesive. This adhesive serves a crucial role in the performance of the insulation.

The paper facing, with its asphalt adhesive, is designed to face towards the inside of the home. This orientation is important for several reasons:


1. Moisture Control: The asphalt adhesive on the paper facing acts as a vapor barrier, preventing moisture from passing through the insulation. This helps to maintain a dry environment within the living space and can prevent mold growth and other moisture-related issues.


2. Energy Efficiency: By facing the paper facing inward, the insulation can better maintain the thermal resistance (R-value) of the material. This means that the insulation is more effective at keeping the home warm in the winter and cool in the summer.


3. Air Sealing: The paper facing can also help to seal gaps and cracks in the building envelope, reducing drafts and improving the overall air tightness of the structure.


4. Aesthetic Considerations: While not as critical as the functional aspects, having the paper facing on the interior side can also provide a cleaner look when the insulation is exposed, such as in an attic or unfinished basement.

It's important to note that the installation guidelines can vary depending on the specific product and local building codes. Always consult the manufacturer's instructions and local regulations to ensure proper installation.

In summary, the correct way to install fiberglass insulation with a paper facing is to have the paper facing facing inwards towards the interior of the home. This ensures optimal performance in terms of moisture control, energy efficiency, air sealing, and aesthetics.

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Regardless of whether fiberglass insulation is installed in a wall, attic, or crawlspace; the paper facing should always face toward the inside of the home. That's because the paper contains a layer of asphalt adhesive which prevents water vapor from passing through it.read more >>