A roof torch is called by many names. You might know it as ‘torch-on roofing’ or ‘torch-down roofing’. But each means the same thing: to use a gas-powered torch to weld roofing felt to your roof.
What Is a Roofing Torch?
Torch-on roofing is used to fix roofing felt to flat roofs and low-slopes. This felt is usually a modified bitumen membrane with three layers: a venting base sheet, underlay layer, and top layer with a mineral cap. This method creates a durable, waterproof seal.
When Do You Need A Roof Torch?
Roof torches are made for laying roof felt on flat and low-pitch roofs. These types of roofs can suffer from leaks when rainwater pools on top. A watertight seal is especially important – and you’ll need a roof torch to create one.
You’ll also use a roof torch to repair existing torch-on roofs and apply additional felt layers.
Roof torches can also attach roof flashing around awkward protrusions or dry out damp surfaces before applying new roofing materials.
What Are the Pros of Using a Roofing Torch?
There are a lot of ways to attach your roofing material to the roof structure. So what makes this roofing product special? Here are the advantageous characteristics of using a roof-on torch.
Cost-Effective
Torch-down roofing is a relatively affordable option that you can buy for around $3.50-7 per square foot. It can cost an average of around $3.50-7 per square foot.
Durable
Torch-down roofing can last 15-20 years, or even longer, with minimal maintenance. The better you take care of it, the longer it will last – as with most roofs.
Waterproof Seal
The main priority of any roof is to keep the elements out of your building. Torch-down roofing provides a watertight seal on your flat roof when used properly.
Versatile
Torch-down roofing is suited to all climates, no matter how hot or cold. The material expands and contracts under changing temperatures without melting or cracking. Roofing felt materials are UV-resistant and able to keep the interior cool – making it an energy-efficient choice.
Even if there is snow on the roof, the watertight seal can prevent water from getting inside the building.
Easy Installation
While there are some safety concerns when it comes to using a blowtorch, this is a relatively easy installation process. And if your roof needs repair, it’s similarly simple to patch up.
What Are the Cons of Using a Roofing Torch?
Torch-on or torch-down roofing might be cost-effective and long-lasting, but there are always problems and downsides to any roofing method.
Safety Concerns
Blow torches use gas to create an open flame. This fire flame is extremely hot. And an open flame can mean a severe fire hazard without proper safety precautions. Operating a blow torch means you’ll need safety training to prevent serious burns and accidents.
Professional Installation
While torch-on roofing is relatively cheap, the cost can increase with labour costs. This method requires a trained professional to ensure your roof is installed properly and safely. But because of this, you might find that your professional roofer charges more for the extra training, insurance and equipment.
Incorrect Installation
You hire a professional to install your torch-on roof, but if they don’t properly seal the seams, you might still end up with leaks. This method is usually very watertight, but like all roofing materials, it depends on effective installation.
How to Use a Roofing Torch Effectively
Got your safety training sorted and equipment ready? Here’s how to use your roof torch if you’re a professional with the right qualifications.
Prepare
You’ll need to clean and dry the roof space. Next, you’ll need to roll out your roofing felt. Make sure it overlaps slightly with each row.
Melting and Adhesion
Don your safety equipment and pass the torch over the underside of the felt and the roof. You should move the torch in even and smooth motions. You might need to go slower in colder temperatures.
You’ll know when the felt is at the right temperature when it forms a sheen. It’s too hot if it starts to smoke. Adjust your movements as you go.
Sealing
You should carefully check the seams after laying down the felt. Take particular care around any features that protrude from the roof, like chimneys or vents. Torch these areas thoroughly to prevent any leaks from getting inside.
Roof Torch Safety Precautions
Know the safety precautions and regulations of your country? It’s important that you update and familiarise yourself with safety best practices to prevent hurting yourself or anyone else.
You’ll be working with a naked flame and very high temperatures, so you’ll need to wear the right safety gear, including heat-resistant gloves and goggles. You should also invest in suitable footwear that will protect you from accidental burns.
Clear of any flammable materials – and make sure everyone is out of the way – before you begin working. Check your equipment is in good condition.
Let a professional handle the job if you’re not confident. Professional roofers have the necessary skills and training, as well as insurance against potential accidents.
Final Thoughts on Roofing Torches
Got a flat roof or low-pitched roof? Keeping it watertight is important, and torch-on roofing is a secure way to keep your home leak-free. Make sure you stay vigilant with safety best practices, and don’t be afraid to consult a professional to get the job done.
FAQs
Do I Need Underlay for Torch-on Felt?
Yes, torch-on felt typically has three layers. You need an underlayer (between 2-4mm) that adheres to the roof and provides a base for the mineral cap sheet to attach to. This layer is important for waterproofing and durability. Some even allow ventilation by letting moisture escape.
How Long Does Roof Torching Last?
Generally speaking, torch-on roofing can last at least 15 years – and often as long as 30 years. The lifespan depends on how well you maintain it and the original quality of the material. Standard roofing felt might only last 10 years in comparison.