Roof repairs and roofing tar go hand in hand. Roofing tar is a restorative layer that plugs gaps and seals the roof against the elements. It adds an extra layer of protection and ensures that damaging moisture is kept out of the core roofing structure.

Roofers have used asphalt-based roofing tar for centuries. It gained and maintained popularity thanks to its impressive waterproofing quality and durability. There are, however, many variants of roofing tar, with different products for different climates and styles required.

In this article, we’ll share insights into roofing tar variants and the application process. You’ll also learn the pros and cons of using roofing tar.

Roofing Tar Origins

Tar was originally used in maritime applications, originating in Scandinavia. The natural waterproof qualities lent itself well to keeping ships watertight. Until the 19th century, much of the tar consumed in the USA was imported. By the 20th century, natural tar was replaced by more efficient and more effective artificial variants.

When Should You Use Roofing Tar?

Technically, this is absolutely a job that you could take on yourself. Many homeowners choose to do so, but most homeowners would agree they’d prefer not to. Tar application isn’t a pleasant process. It is incredibly messy, creates noxious fumes, and can lead to injury through burns. For those reasons alone, it is often left to the experts.

The first step in applying roofing tar is to carry out a roofing inspection. You need a good understanding of the surface and structure that you’re working with before you undertake any repairs or restorations. If the foundation of your roof is secure and no further damage has occurred, you can get the process underway.

The next consideration is the weather. Tarring a roof during snow and rain isn’t feasible. Check the forecast and ensure that you have at least a few days of dry weather ahead of you. The application process won’t take very long at all, but you need to allow it to fully dry and cure. You’re aiming for an ambient temperature of 40-70° F. Failure to do so will dramatically reduce the material’s effectiveness.

What Materials Do You Need?

Whenever you’re undertaking a roofing project, make sure you refer to the only roofing materials checklist you’ll ever need. We compiled a list of the most commonly used materials and discussed their application.

The actual tar that you need will depend on your location. Options include:

  • Coal Tar Pitch: This is the oldest variant and is used less frequently in modern times. It is incredibly UV resistant and very waterproof, but the VOC (volatile organic compounds) that reside within it are dangerous. Plus, it has carcinogenic properties that you’ll want to avoid.
  • Asphalt Tar: Also known as bitumen, this is the most popular tar used today. It is petroleum-based and much safer to work with than coal tar pitch. There are various formulations depending on the climate it is being applied to.
  • Hot and Cold Applied Tar: Hot tar is the tar you see bubbling in a kettle. It is difficult to work with, but the liquid-like application lets it penetrate deep into crevices to seal an area fully. Cold versions are mixed with water or solvents that evaporate after application, leaving the bitumen in place. This is often used for small patch repairs.

There are also several tools and items of equipment that you’ll need:

  • Tar Kettle (for hot tar)
  • Mop or Applicator
  • Roofing Brushes
  • Protective Gear
  • Ladders or Scaffolding
  • Clean-up Supplies
  • Roll Roofing or Roofing Felt
  • Plywood or Sheathing
  • Flashing and Edge Metal
  • Utility Knife
  • Measuring Tape and Chalk Line
  • Brooms and Roofing Spades
  • Ventilation Equipment
  • Fire Extinguisher

Applying Roofing Tar

  1. Once you have completed your inspection, ensure that the area you’re working in is completely clear of any debris.
  2. Put on all your safety equipment, including gloves, eye protection and hard hats.
  3. Give the tar a good stir so that any settlement is removed and you have a good consistency throughout.
  4. Apply the tar using a tar mop, brush or trowel. Spread it as evenly as you can so that the area is completely covered.
  5. Smooth the tar so that an even layer is created with minimal undulations.
  6. Where necessary, add reinforcement. This can be through fiberglass mesh, roll roofing, or another flexible material. Then apply another layer of tar over it.
  7. Allow the tar to dry and cure for a few days.
  8. Inspect the installation to see if you need to add additional tar.

The Pros and Cons of Roofing Tar

Roofing tar has both advantages and disadvantages. There’s a balancing act to be had here.


  • Roofing tar is an affordable way of waterproofing your roof. The base material is cheap and the installation process doesn’t take a huge amount of labor.
  • It’s a great insulator and will likely reduce your home’s energy bills through improved energy efficiency. There’s an argument that you could classify it as an eco-friendly roofing choice.
  • Repairs are straightforward and relatively inexpensive compared to other roofing materials.


  • You need to have an incredibly strong roof structure to hold the heavy weight of a tar roof.
  • The application process can be incredibly hazardous and should be completed by professionals.
  • Many tar roofs are topped by gravel. This gravel can become burdensome as high winds and rain remove it. Plus, it can clog gutters and downpipes.

Considering Roofing Tar?

Roofing tar is an affordable option for homeowners looking to insulate and protect their homes. It isn’t a glamorous roofing material, but it’s one that has proved itself durable and effective over many centuries.

  • Seriously consider the undertaking before applying roofing tar yourself.
  • Always wear protective clothing, including a mask and eye protection, when tarring a roof.
  • Ensure you leave enough time for the tar to dry and cure after application.

Are you thinking about using roofing tar on your home or property? Give Trenton Roofing a call, and we’ll share impartial advice and even give you a free estimate.

Alex Valentino

Alex Valentino – Vice President

Leading the way for the company’s second generation of family and employee ownership, Alex’s mission is to create lasting relationships built on trust and respect by providing uncompromising workmanship and unparalleled customer service. With a focus on safety and consumer education, Trenton Roofing strives to set the bar for the advancement of the roofing industry and the betterment of our local communities. When he is not working, Alex can be found traveling with his fiancée, watching football or playing a relaxing round of golf with his friends.