Roofing tar is excellent at waterproofing and fixing holes in your metal roof. But too much of it or using it improperly will result in ugly stains – its to messy and sticky.
In some cases, the tar mess that’s created might be pretty hard to remove without taking off chunks of your roof.
But wait, before you accept the fact that these are permanent stains and you need to get a new roof installed, you should try a few things first.
This guide will show you how to remove roofing tar from metal surfaces without damaging the roof itself. So, do not panic; follow the tips and steps below.
Roofing Tar Removal – What to Use?
Roofing tar is a black, oily, and sticky substance that’s used on flat roofs to patch leaks. It’s composed of coal tar and petroleum derivatives. The majority of them are dark blackish in color, although some producers have introduced lighter hues such as silver and white.
While roofing tar isn’t very easy to get off, it can be removed from most surfaces (like roofs, metal tools, and hands) using WD-40 or an Oven Cleaner if you are ready to put in a little elbow grease.
Homemade tar removers such as kerosene and diesel fuel can also work on roofing tar spills, but they are less effective and can be messy and time-consuming if you don’t have the right tools available.
It’s also not a good idea, to apply these flammable and hazardous substances inside your house or on roofing tiles constructed of asphalt and concrete as they can stain these materials.
How to Remove Roofing Tar with WD-40?
As I said, using WD-40 is the easiest and fastest way to strip off toxic roofing tar from metal surfaces. Here are the general instructions and guidelines you need to follow.
What you will need:
- A ladder
- Safety goggles
- Rubber gloves
- A putty knife or scraper
- WD-40 or oven cleaner
- Rags, soap, and water
- A power washer (optional)
Put on your safety goggles and rubber gloves to protect your eyes and hands from the chemicals.
Climb up the ladder and assess the situation. If the spilled tar has stained a small area on your metal roof and is still fresh, you can probably remove it with a putty knife or scraper.
If the tar is in a larger area or has been there for a while, you might need to use WD-40 or an oven cleaner.
Apply WD-40 to the area with a rag, or if you are using a sprayer, spray generously over the area that you need to treat.
Let it sit for a few minutes to loosen the tar and then scrape it off with a putty knife or scraper.
If the dried tar is still stubborn, use a heat gun to melt it. Ensure you do not heat the tar too much, as it can damage or warp the material you are trying to clean.
Apply more WD-40 and let it sit for a few more minutes. You might need to do this a few times to get all of the tar off.
Once you have removed all of the tar, wash the area with soap and water to remove any WD-40 residue. If it’s convenient you can use a power washer to ease the job.
Removing Roofing Tar from Metal with Ammonia
By following the DIY steps above, you should be able to remove maximum roofing tar and stains. But if that doesn’t seem to work, another best way is by using ammonia and baking soda.
Here’s how to use them…
- Mix together ammonia and baking soda in equal parts and apply them to the area with tar stains.
- Let it sit for 30 minutes, and then use a wire brush to remove it by applying enough pressure on the surface.
- Do not apply too much pressure as it can damage the underneath surface.
- Finally, rinse off the residue with water and dry the surface with a cloth.
Tips and Warnings
Usually, to meet roofing standards, coal tar must be refined and processed before it’s used in roofing tar intended to seal, join, or repair roofs that have suffered damage or are deteriorating slowly. These can either be applied by trowel or can be applied like paint or caulking tubes. Although the newer formulations are asbestos free, they may contain solvents, adherents, mineral fillers, and fibers that are considered carcinogenic.
Bitumen, tar paper, gravel, and asphalt-based adhesives are also available as tar materials. Some of them are made of petroleum distillates that are used to adhere various types of roofing material, such as shingles, to the underlying structure.
So, one important thing to keep in mind during the application, as well as the removal process, is that the tar is a very toxic substance, and the odor it creates can be harmful to your health if inhaled for a long – it’s, therefore, important to take all the necessary safety precautions.
Plus, it can be sensitive to temperature. This also means when the temperature rises to extremely high levels, roofing tar will transform into a liquid. So, it should not be used on steep roofs to avoid running off at extremely high temperatures. It’s however perfect for flat and low slope roofs, allowing it to self-heal and seal leaks.
Overall, roofing tar is an extremely sticky and messy substance that can be challenging to remove. Products such as tar removers that are specifically designed to remove roofing tar can be found at your local hardware store, which can make the removal process easier. But if you’re looking for a more natural solution, you can use a mixture of ammonia and baking soda or even your everyday lubricant, WD-40.
Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.