How to Use a Utility Blade Roofing Knife

Clean cuts matter. They improve the fit, finish, and integrity of your roofing system. Whether trimming shingles, slicing roofing membrane, or working with insulation, choosing the right roofing utility knife and using it properly determines your speed, precision, and safety.

Everhard Products’ toolmakers and industry experts have worked alongside roofers for decades. Here’s their advice on how to get the job done right the first time with this guide to cutting smarter.

Choosing the Right Roofing Knife

Not all roofing knives are created equal. (Just ask any roofer!) To get consistent results and a smoother workflow, look for these features when selecting a tool for roofing tasks:

• Non-slip grip: Roof work can be sweaty, messy, or wet. A textured or rubberized handle gives you more control and helps prevent accidents.
• Easy blade replacement: Look for roofing utility knives that allow fast, tool-free blade changes so you can keep working without delays.
• Blade versatility: The right roofing utility blades make all the difference. Match the blade to your material – hook blades are great for shingles, while straight blades offer versatility for use with a variety of roofing materials.

Essential Safety Precautions

Even the best roofing hand tools can be dangerous and cause injuries if used carelessly. Prioritize safety before making any cuts by following these safety precautions:

• Wear proper gear: Use cut-resistant gloves, protective goggles, and a dust mask when working with fiberglass or insulation.
• Clear your area: Remove unnecessary tools or materials from your workspace to reduce trip hazards or obstructions.
• Secure footing: Be sure you establish firm and stable footing before using any knife, especially on sloped or wet surfaces.

Preparing for the Cut

A little prep goes a long way toward a cleaner result. Here’s how to set up your cut so that your work is done with precision:

• Use a straight edge or guide: Line up a straight edge or metal ruler along the cut line to help maintain control.
• Mark clearly: Use chalk or a marking pencil to outline your cut, especially for materials such as roofing felt or membrane.
• Stabilize your material: Secure the roofing material so it doesn’t shift as you cut. If necessary, use clamps or your body weight to hold it in place.

Making the Cut

Once your surface is marked and secure, follow these steps to get a clean, controlled cut:

1. Grip the knife firmly, but not too tightly. Use your thumb along the spine to guide the cut. This will help you maintain control and avoid hand fatigue or slips.
2. Score the line with steady, even pressure. This applies to nearly all cuttable roofing materials to avoid jagged edges and ensure a cleaner finish.
3. For thick materials, make multiple passes. Avoid forcing the blade – let the blade do the work. This is especially important for fiberglass shingles, insulation, and roof membrane. Avoid forcing a single deep cut.
4. For rigid materials, like asphalt shingles or foam insulation, bend along the score line to snap the material cleanly. For more flexible materials, like membrane or felt, complete the cut with additional passes.

Tips for Different Roofing Materials

Different roofing materials require different techniques for roofing knives. Here’s how to get clean cuts across common materials using the right roofing utility blades and techniques:

Asphalt Shingles

Use a hook blade and score from the back side of the shingle. This gives you a cleaner, more precise edge and avoids damaging the granule coating on the front.

Fiberglass Shingles

Fiberglass singles are more rigid and prone to cracking or fraying. Use a sharp roofing knife blades and take your time, making multiple passes rather than forcing the cut. Always wear a dust mask and protective gloves – fibersglass particles can irritate the skin and lungs.

Roofing Felt

For roofing felt, use a straight blade and a guide like a metal ruler or straightedge. Apply steady pressure and cut slowly to avoid tearing or jagged edges, especially in damp and humid conditions when the felt is most fragile.

Insulation

When cutting roof insulation, opt for a longer utility blade if available. Or better yet, use a knife specific for insulation cutting. Make light, repeated passes rather than one deep cut. Avoid compressing the material as you cut – keeping it loose helps maintain clean, even edges and proper fit..

Roof Membrane

Roof membranes are flexible and prone to stretching. Use a sharp, clean blade for every cut. This prevents the material from bunching or tearing. For best results, always work on a stable, flat surface.

Elevate Your Roofing Experience with Everhard Tools

All roofers need the right knife for the job. Professionals trust Everhard tools for one reason: we build these tools to meet real jobsite demands. Our USA-made commercial roofing hand tools  – including roofing utility knives and roofing knife blades– are built to strict quality standards for long-lasting performance, ergonomic comfort, and ease of use.

We offer fast shipping, responsive support, and custom solutions for the most demanding and specific jobsite needs. Contact us or call 1-800-298-2832 to talk with our experts about upgrading your commercial roofing tools today.