What Is Torch Down Roofing and How Do You Apply It?

Torch down roofing is a tough, long-lasting flat roof system that’s installed using heat to bond the material directly to the surface. It’s trusted by pros for its waterproof performance and durability — especially on low-slope roofs.

In this guide, we’ll break down what torch down roofing is, how to install it, and what tools you’ll need — including links to the exact gear you should have on hand.

🔥 What Is Torch Down Roofing?

Torch down roofing is made from modified bitumen membranes that are applied with an open-flame roofing torch. The torch melts the underside of the membrane, which fuses to the roof for a watertight seal.

Types of Torch Down Systems:

  • Two-layer system: base + cap sheet

  • Three-layer system: base + interply + cap sheet (best for heavy-duty protection)

Membranes are typically made from APP (atactic polypropylene) or SBS (styrene-butadiene-styrene), both known for excellent weather resistance and flexibility.

🧰 Tools You’ll Need for Torch Down Roofing

Make sure you’ve got the essentials before starting:

🛠️ How to Apply Torch Down Roofing1. Clean the Roof Surface

Use a broom or blower to clear debris. A clean surface = better adhesion.

2. Prime the Roof (if needed)

Apply primer to dusty or aged surfaces for better bonding.

🔗 410 Quick Dry Asphalt Primer

3. Mark and Measure

Use a measuring tape and chalk line to lay out membrane alignment.

🔗 25' Tape Measure with Dummy Read

🔗 Chalk Box with 100' Line All Metal Retail Carded

4. Install Base Sheet

If using a multi-layer system, install the base sheet first using nails or adhesive.

5. Apply Torch Down Membrane

Unroll the membrane and use your roofing torch to heat the back as you roll it into place. Work in small sections and always keep the flame moving.

🔥 Important: Wear heat-resistant gloves and handle the torch with care.

🔗 Magnum Torch Combo

🔗 3242 Extra Large

6. Seal Seams and Edges

Use a seam roller to apply pressure to overlaps and joints.

🔗 100 lb. Membrane Roller - Shop Roofing Accessories

7. Final Inspection

Look for air bubbles, missed areas, or lifting seams. Reheat and roll again if needed.

✅ Benefits of Torch Down Roofing

  • Lasts 15–25 years

  • Strong waterproofing

  • UV and heat resistant

  • Low maintenance

🏁 Final Thoughts

Torch down roofing is tough, time-tested, and trusted by roofers across the country. If you’re looking for a weatherproof flat roof that can take a beating — and look good doing it — this system is a solid choice.

Ready to tackle your next flat roof job?

👉 Magnum Torch Combo

👉 Heavy Duty Contractor Bags