How to cover bitumen paint?

Hi,

We have a concrete garage that’s been covered/waterproofed with paint on Bitumen. It’s fine, but being black the garage does feel a bit like tomb.
I was wanting advice on the simplest way to cover it in something brighter. The main issue would seem to be adhesion to the Bitumen. Resene do have a special primer which then allows Bitumen to be painted, but I was wondering if there were other options. Not worrying about any fancy, would be happy with a simple mortar product but I suspect that would stick to the Bitumen.

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EricL

Hi @Millerman

Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your question about painting over bitumen paint.

In order to give our members a better idea of what's been painted, would it be possible for you to post a few photos of the surface area? This will give our members a chance to assess its condition. We can then make recommendations on how to proceed.

We look forward to seeing the photos.

Eric

Millerman

Hi,

I could put up a photo but not sure what it would add. It’s literally just a concrete block wall that’s been covered in bitumen paint. A photo would just show a black wall.
My question is just around effective options for covering it in something that isn’t black.

Dave-1

Good afternoon @Millerman and @EricL

I had the same question myself when I used bitumen to waterproof the bottom couple of courses of brickwork for my garage. It wanst high on the list but if I could paint it something closer to the brickwork colour it would blend. Its not a high priority but when I saw the question Ithought "Bingo"

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Thanks

Dave

EricL

Hi @Millerman

I was curious if the bitumen paint is thick or is it flat and well spread over the surface of the wall. Some bitumen paint systems leave a lumpy surface while others leave a hard surface with a soft rubbery feel when pressed.

A possible primer you can use is Zinsser 470ml B-I-N Primer Sealer Stain Killer. It is a shellac-based primer-sealer stain-blocker. It is formulated to seal, prime and block out tough stains on previously painted or new work.

However, before you begin, please allow me to double check with Zinsser. As soon as I have more information, I'll get back to you.

Thank you for your patience.

Eric

Dave-1

Thank you @EricL

Not trying to steel @Millerman 's question 🙂 My bitumen paint is flat and a little soft when pushed against. It really stuck nicely. I will keep in mind that stain blocker tho! 😲 I hadnt heard of that before.

Thanks

Dave

EricL

Hi @Millerman

I've spoken to the Zinsser information team, I'm sorry but they don't have any technical data to guarantee that the Zinsser BIN primer will totally seal the bitumen paint. I recommend testing a small area first and observe for 48hours. In that amount of time, you'll be able to tell if the Bitumen paint will bleed through the primer. The advantage of using a Shellac based primer is that you can use either a water-based or oil-based topcoat.

If you have any other questions we can help with, please let us know.

Eric

Millerman

Hi,

Thanks for that and I’ll look into it.

I was also wondering about the possibility of a non painted solution. There are mortar like products, but I was unsure whether they’d adhere to the bitumen paint?

Tyro

Hi @Millerman , @Dave-1 and @EricL

I don't know anything about the properties of bitumen so apologies if I'm way off course here BUT! Our roads get painted with lines so maybe you could approach the people who paint the roads? Professor Google tells me this company might be able to shed some light on it for you:

https://colourcoat.com.au/

Good luck! 🤗

MitchellMc

Hi @Millerman,

I am not aware of any paint or mortar products that are designed to go over bitumen paint. Bitumen paint is typically used as a functional waterproofer and not something that would be used if the surface was then to be overcoated. Given this, coating product manufacturers wouldn't typically be engineering their products to adhere to bitumen-based paints.

Do you happen to know what the product was that was used? Perhaps the manufacturer of it might be aware of a coating that can be applied over it. In the case of our Crommelin 4L Blackseal Heavy Duty Bitumen Waterproofing Membrane the manufacturer advises that it is "Not suitable to be painted, tiled over or over-coated."

Please let me know if you have any questions.

Mitchell

Cedes

I asked Google about the same thing and it said to use a shellac based overcoat. I'm going to try that myself as I waterproofed joints on a roof and apparently bitumen needs to be sealed to protect it from breaking down in UV rays. I'm going to use that one mentioned above which the manufacturer says they don't know if it'll go over bitumen. I'm betting it will and will risk it. 😁

EricL

Hello @Cedes

Thank you for sharing your proposed plan. Please keep us updated with your progress, it would be interesting to find out how the overcoat will work on the bitumen surface and if it will manage to resist the bleed through of the bitumen colour.

Eric

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