Torch Down Roof: Pro and Cons

If you plan to install a torch down roofing on your property, you need to know its pros and cons. You have probably seen this type of roofing system in commercial buildings. It is common on flat roofs where snow, rain, or ice can collect easily and stay long.

This guide will pass you through all you need to know about torch down roof, including its advantages and disadvantages. You will be able to make informed decisions. Finally, you will find yourself with a roof that can protect you against water leaks and UV rays.

Let’s get going!

What Is Torch Down Roofing?

A torch down roofing is a process of applying multiple layers of modified bitumen using an open-propane torch. It is a rolled roofing product consisting of a robust waterproof roof membrane fixed in a thick asphalt layer. The type of roofing tightly bonds to metal flashings and moves them while still sustaining the grip.

The roofing system covers the entire roof at a thickness of approximately 4mm. Once the roofing material gets hot enough, it adheres to the roof surface, and the seams melt together to create a watertight seal. Since installing the torch-down roofing is a complex process, working with Roof Master & Construction professionals is essential.

Types of Torch-On Roofing

So, what are the different types of torch-on roofing? Here are the two types.

1.            Two-layer Torch Down Roofing

Two-layer systems come with a base layer and a cap sheet or torch-on layer. It consists of a smooth base ply and one ply with a granular surface. Also, the roofing systems are cheap and easy to install, though less durable.

2.            Three-Layer Torch Down Roofing

The roofing system comes with an asphaltic board, a smooth base ply, and a top ply with a granular surface. Its notable difference with the two-layer torch-down roofs is the extra cap sheet or torch-on coat. Thankfully, three-layer torch-down roofs last longer.

Torch Down Roofing Pros

Various benefits make torch-down roofing a better option for commercial roofs. Some of the advantages include:

Leak Resistance

One of the best torch-down roofing merits is its resistance to leaks. The roofing system heat-welding mechanism ensures protection from leaks due to its wholly melted torch-down surface.

High-Quality Fire Resistance

Torch down roofing materials is hugely fire-resistant despite melting with heat welds. In addition, the modified bitumen roofs come with added density hence reducing contribution to fire hazards after installation.

Excellent UV Protection and Insulation

Due to its airtight seal and excellent material density, the torch down roofing advantage is its ability to reflect UV rays. Torch-down roofing systems also offer outstanding insulation for any property.

UV rays penetrate thin single-ply membranes. However, with torch down and high-density PVC roofs, you will find no issues with improving your property’s indoor temperature.

Absence of Noxious Fumes

Modified bitumen is the heir of the old tar and gravel roof. However, substituting a heat weld for tar eliminates the presence of post-installation harmful fumes. So, modified bitumen and PVC roofs permit tenants to move into the property soon after installation.


While other roofing materials crack, torch-down roofs come with extra rubber to allow the roofing materials to contract and expand in extreme heat and cold. Its flexibility is significant merit and makes it perfect for flat roofs.

Easy to Repair

Torch down roofing is easy to repair compared to other roofing materials. The roofing material rolls on, and you can sell them quickly. Besides, the repairing process is less intensive and less costly than fixing distinct types of roofs.

Torch Down Roofing Cons

Everything that has its pros also comes with its share of demerits. Here are various disadvantages of torch-down roofing.

Poor Resistance to Tear

Torch down roofing withstands foot and fire traffic. However, the roofing system is not resistant to tears caused by windstorm debris and hailstones. Such elements damage and tear off parts of your roof. Though you can cover the injuries using extra modified bitumen, it can affect the general appeal of your property.

Need for Fire Permits

Heat welders are risky materials. If you wish to install a torch-down roof on your own, you will require a fire operating license. That means that you must prove your skills in using heat welds or torches to gain consent to install the torch-down roof by yourself.

Stuck Water

It is likely for water to get stuck between the layers of rolled roofing during installation or repair. Therefore, torch-down roofing is appropriate on sunny days.

Roofing Materials to Use in a Torch Down Roof

Torch down roofing is a composition of various materials brought together for a safe and waterproof roof. Some of the best materials include the following.

  • Modified bitumen – It is the leading roofing material used in torch down roofing.
  • Atactic polypropylene (AP) – the flexible plastic comes with a low melting point and can withstand high and low temperatures.
  • Styrene Butadiene Styrene (SBS) is a rubber used in modified bitumen with a low melting point and high flexibility.
  • Thermo-Fusible Film – Acts as the first layer of underlayment when installing a torch down roof.
  • Overlay Board – the overlay board supports the torch-down roofing membrane.
  • Vapour Barrier – its work is to protect your roof from moisture damage.
  • Granular Cap Sheet – the sheet gets added along with a smooth cap sheet to enhance your roof’s protection and sealing.
  • Flashing – Flashing protects any features on your roof surface, including skylights and chimneys.

Is it Possible to Walk On a Torch Down Roof?

Walking on a torch-down roof is safe, especially when putting on your safety gear, including work boots. However, you should always perform annual checkups on the conditions of your roof. That will help you keep it at its best throughout the years.

Where to Use a Torch Down Roof

You can apply a torch-down roof on concrete, metal decks, and timber flat roofs. Also, it is easy to use the roofing system to cover your sheds, garage, residential houses, and significant commercial buildings.

Final Words

If you need a durable roofing system, a torch-down roof is your best choice. Also known as torch-on roofing, the roofing membranes offer a rapid and straightforward application. Always hire a highly-skilled professional to install the roofs. Touch down shelters also provide an ideal solution for remedial overlays, detailing work, and small area patching.

Related Posts

Leave a Comment