What Are the Disadvantages of Bitumen waterproofing Paint?
Bitumen waterproofing paint is a popular choice when it comes to protecting surfaces from water damage. It is often used on roofs, basements, metal surfaces, and even walls to keep water out.
While it has many good points—like being affordable, strong, and easy to apply—it also has some disadvantages you should know before choosing it for your project.
In this article, we will take a simple and clear look at the downsides of using bitumen waterproofing paint, and help you make the right decision.
What Is Bitumen Waterproofing Paint?
A Quick and Easy Waterproofing Solution
Before we get into the disadvantages, let’s first understand what bitumen paint is.
Bitumen waterproofing paint is a black, thick, tar-like liquid made from bitumen—a sticky, black substance that comes from crude oil.
When you apply it on surfaces like concrete, metal, or wood, it creates a strong, waterproof layer that stops water from entering.
It is often used for:
Roofs
Basements
Foundations
Water tanks
Pipelines
Bitumen paint is popular because it’s simple to apply, cost-effective, and works well for many surfaces.
However, like any other material, it is not perfect.
Major Disadvantages of Bitumen Waterproofing Paint
Important Things You Should Know
Now let’s explore the main disadvantages you might face when using bitumen waterproofing paint.
1. Limited Lifespan
Bitumen Paint Does Not Last Forever
One of the biggest drawbacks of bitumen paint is that it does not last as long as some other waterproofing methods.
Typically, bitumen coatings may last between 3 to 7 years depending on the quality of the paint and the conditions it faces.
Over time, it can:
Dry out
Crack
Peel off
Lose its waterproofing power
Tip: Regular inspection and maintenance are needed to keep the protection strong.
2. Sensitivity to Temperature Changes
Heat and Cold Can Affect the Coating
Bitumen paint can become soft and sticky in hot weather.
In cold weather, it can become brittle and crack. These temperature changes can slowly damage the coating, leading to water leaks.
Common problems include:
Melting or softening under strong sunlight
Cracks forming during cold winters
Early wear and tear
Tip: In areas with extreme weather, bitumen paint might not be the best choice.
3. UV Damage
Sunlight Can Weaken the Paint
If bitumen paint is exposed directly to the sun, UV rays can break down the material over time.
This can cause:
Fading
Cracking
Loss of flexibility
Early aging of the waterproofing layer
That’s why bitumen paint is often covered with another protective layer like aluminum paint or gravel to protect it from sunlight.
Tip: Always check if your bitumen coating needs an extra layer for UV protection.
4. Strong Odor During Application
The Smell Can Be Unpleasant
When you apply bitumen paint, it gives off a very strong smell that many people find unpleasant.
The smell comes from the solvents used in the product.
Possible issues:
Can cause headaches or nausea
Needs good ventilation during application
May take a few days for the smell to disappear
Tip: Always wear a mask and work in well-ventilated areas when applying bitumen paint.
5. Surface Preparation Is Very Important
Dirty Surfaces Will Cause Failure
For bitumen paint to work properly, the surface must be clean, dry, and free of dust, oil, or loose particles.
If you apply it over a dirty surface:
It won’t stick properly
Water may seep under the coating
The waterproofing will fail quickly
Tip: Spend enough time cleaning and preparing the surface before applying bitumen paint.
6. Not Suitable for High-End Finishes
Appearance Is Not Very Attractive
Bitumen paint dries to a dark black color, which may not look very attractive in visible areas like walls, terraces, or open roofs.
If looks matter to you:
Bitumen paint may not be the best option
You might need to cover it with another decorative coating
Tip: Use bitumen paint mainly in hidden or structural areas rather than areas that are visible.
7. Health and Safety Concerns
Chemical Ingredients Can Be Harmful
Bitumen paints contain chemicals and solvents that can be:
Flammable
Harmful to breathe in large amounts
Dangerous if they come into contact with skin or eyes
Tip: Always follow safety instructions and use protective gear like gloves, goggles, and masks.
Situations Where Bitumen Waterproofing Paint May Not Be Ideal
Know When to Choose a Better Option
Bitumen waterproofing paint may not be the best choice if:
You need a very long-lasting waterproofing solution (more than 10 years)
You live in an area with very hot summers or freezing winters
You want a waterproof layer that looks neat and decorative
You are waterproofing drinking water tanks (unless you use a non-toxic certified product)
In these cases, you might want to look at other options like:
