Questions about bitumen based paints? We hope we’ve answered them for you in this blog! Natural bitumen has been used, tried and tested for thousands of years and is known for its waterproofing and adhesive qualities. Natural bitumen is found in deposits such as oil sands and pitch lakes, while refined bitumen is obtained as a residue from the distillation of crude oil. Bitumen paints and coatings are popular in many industries and leisure sectors.
What is bitumen paint used for?
Bitumen paint is suited to many different applications because of its weatherproofing, corrosion resistance and adhesive properties. It is primarily used as a protective coating for buildings, structures and items constructed from iron, steel, concrete, masonry and wood. It is generally seen as an economical option and can be used both above and below water or ground.
Where can you use bitumen paint?
You’ll find bitumen paints used in all sorts of situations. A versatile paint, it can be used on both ferrous and non-ferrous metals as well as concrete, wood and masonry. It’s frequently used on metal guttering, fire escapes, stairways, ladders, railings and fences. In the marine sector, bitumen paints are commonly used on boat hulls. Most people associate bitumen with roofing and it is of course commonly used as a weatherproof overcoating for flat roofs, felt roofing and industrial roofing. It is ideal for this purpose as it dries fast which is great advantage here in the UK where it fluctuates from warm to wet so quickly! Bitumen is also used in roofing compound for quick repairs, in mastic for sealing and for glueing roofing felt.
Bitumen is still sometimes used for damp proofing below-ground brickwork and concrete foundations. As it is contaminant-resistant and has no odour, the coating is also suitable for water tanks (not drinking water) and similar applications.
How long does it take to dry? What does it look like?
Most bitumen paints are dry in two to four hours. When dry, bitumen paint creates a thin black film which has the advantage of being odour free. Our bitumen paint and bituminous barn paints have a slightly glossy rather than a matt finish.
How long will bitumen paint last?
Bitumen paint is usually long lasting. If applied to a porous surface like masonry it will last longer than when applied to less porous surfaces, especially those subject to long hours of extremely hot sun. Narrow boat owners tend to do their re-coating every three to four years. Bitumen paint on a felt roof will usually last 2 to 3 years before it shows signs of drying out. To extend and preserve the life of the felt roofing, consider apply a protective coat of solar reflective, bitumen aluminium paint.
Are there any disadvantages to bitumen paint?
- For some applications, it is not the most attractive option
- It is also generally only available in black. We offer bitumen paint in green and our bitumen based barn paint comes in several shades but they are on the darker side
- Bitumen paint can be difficult to apply in very cold conditions
- You are limited to what you can overcoat with it as it will bleed through certain top coats
- While it’s generally reasonably heat and UV stable, its lifespan may be reduced in extremely hot and sunny countries.
What are the advantages of bitumen paint?
- Usually cheaper than many other coatings offering similar weather proofing performance, it’s an economical option
- Suited to application on multiple surface types from iron, steel, concrete through to masonry and wood
- Odour free
- Quick drying
- Good adhesive properties
Here are some common bitumen paint related questions which we have received from customers:
Is bitumen paint toxic to plant life?
Once fully cured to a dry film, our bitumen paint is not toxic to plant life. In fact it would be ideal for painting the insides of wooden planters etc. Similarly, bitumen paint can be applied to wooden posts to be buried in the ground as long as it is allowed to fully dry before coming into contact with the soil.
Can Bitumen paint be applied onto OSB Board or Sterling Board?
Bitumen paint can be applied to most types of wood and engineered board such as sterling board and OSB board. However, some OSB has a wax finish which the bitumen paint may struggle to adhere to. If you can remove the wax, all the better, if not, try a test patch first. Another customer asked whether bitumen paint would cure seeping water through wooden plyboards on a shed. The answer in general would be yes, as long as there are no actual holes present. A minimum of two coats would be recommended in this case.
What precautions to take when applying bitumen paint?
Protect skin and eyes and apply in well ventilated areas outdoors, do not inhale. Do not apply near open flames, sparks, heat or hot surfaces. sources. Dispose of any waste responsibly as it is toxic to wildlife. Do not swallow.
Would bitumen paint be suitable for protecting the underside of a steel trailer?
Bitumen paint would be an economical solution for this purpose and will provide protection from water and to some extent, knocks. The only thing that might affect the long term properties of the paint is attack from salt on the roads etc. But it’s generally a good solution that will give two or three years protection, before recoating is necessary.
Should bitumen paint be applied before or after roofing felt?
Felt adhesive such as Carbobond, is a solvent based mixture of bitumen, fillers and fibres, formaluated for bonding felt (as the name suggests), so it is better to apply this first then the roofing felt which will (of course) adhere to it. Bitumen paint can then be applied on top of the roofing felt for extra protection and/or aesthestics.
Will bitumen paint cure a leaking concrete roof?
Bitumen paint is an economical solution for this problem, if there are serious cracks in joints etc, repair with roofing compound, then paint over with Carboblack. We have also been asked what products can be painted over a previously bitumen painted concrete roof. Generally, it is fine to paint a bitumen paint over another bitumen product; if the reason for painting is to change the colour, then consider a bituminous barn paint like Carbolustre or Green bitumen paint. We do not usually advise applying alternative coatings over bitumen paint as the bitumen tends to bleed through the topcoat.
Application tips for bitumen paint
Prepare the surface well by removing dust, oil, grease, old coatings and surface contaminants. A primer is not usually needed with bitumen paint but occasionally for additional protection of bare metal surfaces, prime with Zinc Rich Primer or Metal Primer. Use fast dry etching primer for non-ferrous metals.
Best results are obtained in warm (minimum 10°C), dry conditions and we recommend application of 2 coats. Use Conventional or HVLP spray, brush or roller.
Our bitumen paint products
Here are details of some of our bitumen based paints. As always, we’re available to answer any questions you have via our contact page or the online chat facility.
Carboblack is our black bitumen paint which has great weatherproofing properties. This solvent based bitumen paint dries to form a weatherproof film. It widely used in the industrial, agricultural and marine sectors. Some examples of Carboblack Bitumen Paint in use are: boat hulls; structural steel; concrete roofing, pipelines and asphalt surfaces.
Carbolustre 2000 Barn Paint is our flexible, weatherproof paint for sheds, barns, outdoor wood and metal. Our barn paint is a mix of high blend bitumen and alkyd resin waterproofing – not only attractive, but with great protective qualities. It can be applied directly but will perform best when coated over selected Palatine primers and undercoats. Choose from 5 subtle shades grey, olive, brown, green and black.
Carbosil Bitumen Aluminium is for over-coating bitumen based surfaces. It helps protect surfaces from heat/UV light damage, with a decorative coating and will enhance the lifespan of bitumen-type roofing materials. The flexible, heat resistant and solar reflective surface has outstanding weather resistance and durability. Ideal for use on roof structures, storage tanks, silos, mobile homes and caravan roofs. Reflects heat in the summer and insulates in the winter.
We also supply roofing mastic, roofing compound and felt adhesive.