Understanding the Plastic Strip on Back of Shingles

The plastic strip on the back of shingles is a common feature in many asphalt and architectural shingle products. This protective or functional layer can influence installation speed, insulation behavior, and long-term performance. This article explains what the strip is, why it’s present, how it affects installation, and best practices for handling it to protect roof integrity and warranty coverage.

What The Plastic Strip Is

The plastic strip on the back of shingles is typically a thin film or molded spacer that serves multiple roles during manufacturing, shipping, and installation. In some shingle lines, it functions as a protective release film to prevent premature adhesion of self-sealing tabs or to keep the exposed adhesive area clean before installation. In other products, the strip acts as a moisture barrier or a nailing guide that helps installers locate the proper nails. The exact purpose can vary by brand and product line, so checking the manufacturer’s literature for a given shingle is essential.

Purpose And How It Works

The primary purposes of the back-strip can include:

• Protection During Transport: A plastic or film layer prevents damage to the shingle surface and adhesives while pallets are handled and stored.
• Pre-Installation Cleanliness: A removable film keeps the adhesive areas free of dust and debris, ensuring proper seal once the top layer is installed.
• Controlled Adhesion: For self-sealing shingles, an internal spacer or film helps regulate when and how the tabs bond to the roof deck, contributing to wind resistance.
• Ventilation And Drying: Some back-strips are designed to minimize moisture entrapment during storage, reducing the risk of warping.

Installers should understand the specific product’s instructions. If the strip is intended to stay, it can contribute to the shingle’s performance. If it’s supposed to be removed, leaving it in place may hinder proper sealing or ventilation and could affect warranty coverage.

Installation Impacts And Best Practices

During installation, the plastic back-strip should be managed according to the manufacturer’s instructions. Key considerations include:

• Follow the Nailing Line: Align nails with the designated nailing line on the shingle. Improper nailing can compromise wind resistance regardless of the back-strip.
• Remove When Required: If the product requires removal of the back-film before or during installation, do so per guidelines. Leaving a film in place can cause poor seal or moisture entrapment in some designs.
• Inspect For Damage: Check the back-strip for tears or damage that could affect performance or indicate improper handling during manufacturing or storage.
• Store Properly: Store bundles on a flat, dry surface and protect from prolonged exposure to sun, which can degrade the plastic or adhesive.

Correct handling helps achieve the expected thermal performance, wind resistance, and long-term durability that the shingle is designed to deliver.

Removal, If Necessary, And Safety Tips

If the back-strip must be removed, follow these steps to minimize risk to shingles and the roof deck:

1. Test A Small Area: Remove the strip from a low-slope panel first to observe any changes in adhesion or seal behavior.
2. Use Gentle Tools: Use a soft plastic putty knife or your fingernail to lift and peel the film without scratching the shingle surface.
3. Work From Bottom To Top: Remove the film toward the upper edge to prevent debris from falling under the shingles.
4. Clean Adhesive Residue: If any adhesive remains, follow the manufacturer’s guidance for removal to avoid compromising the self-sealing mechanism.
5. Inspect For Uniform Seal: After installation, verify that the tabs seal uniformly and that there are no gaps that could allow wind uplift or water intrusion.

If there is any doubt about whether the back-strip should be removed, consult the shingle manufacturer or a licensed roofing professional. Warranty terms often hinge on following the correct procedure.

Potential Issues And When To Contact A Pro

Leaving or removing the plastic back-strip improperly can lead to performance concerns. Common issues include:

• Weak Wind Resistance: Improper sealing due to residual film can reduce wind uplift resistance in certain shingle lines.
• Moisture Entrapment: In some designs, a residual back-strip can trap moisture, promoting mold growth or deck rot if not managed correctly.
• Warranty Problems: Unauthorized alteration of the back-strip may void warranties or service agreements.

When in doubt, a professional roofer can assess the back-strip’s role for the specific product, confirm proper installation, and ensure warranty compliance.

Maintenance, Storage And Longevity

Proper storage of shingles with back-strips is essential to prevent damage before installation. Tips include:

• Store Off Ground: Keep bundles on a clean, dry surface with good ventilation to avoid moisture buildup.
• Protect From Sun: Use covers or shade to limit UV exposure that can degrade back-strips and adhesives.
• Handle With Gloves: Wear gloves to prevent oils from hands contaminating the back-strip or shingles.
• Rotate Stock: Use older stock first to minimize exposure time before installation.

Adhering to these practices helps maintain shingle performance, ensuring that the back-strip serves its intended function when the roof is completed.

FAQs About Plastic Strips On Back Of Shingles

• Do all shingles have a plastic strip on the back? No, it varies by brand and product line. Some have a removable film, others have a non-removable spacer, and some may not have an identifiable back-strip.
• Should I remove the back-strip before installation? It depends on the product’s instructions. Always follow the manufacturer’s guidance to avoid warranty issues.
• Will removing the back-strip affect warranty? It can, if the procedure is not approved by the manufacturer. Check the warranty terms for specifics on back-strip handling.

Understanding the plastic strip on the back of shingles helps homeowners and installers make informed decisions about installation practices, maintenance, and warranty protection. Following brand-specific guidance ensures optimal performance, durability, and the intended life span of the roofing system.