Advice needed on potentially failed rubber roof paint

leadlion

I’ve used Isoflex liquid rubber to paint a parapet. When first applied a year and a half ago it had a nice shiny finish. Now, the whole painted area has turned dull and matt. On very close inspection, there is crazing/cracking.

I used half a tin of 0.75L Isoflex Special Primer, followed by a full tin of 0.75L Black Roofing waterproofer (I think I did 2 coats). The area is just the one seen in the photo. It’s about 5 metres by 0.2 metres.

Thompsons/Ronseal have suggested that the application might have been too thin (which I don't really agree with), and that water has ingressed underneath the surface. However, someone from another forum has suggested to me that it's normal for it to go dull and it's doing its job.

Hoping anyone with experience with these sort of products can tell me their opinion. Should I leave alone if not actually leaking?

Bendy_House

The bumpy bits in the close-up pic, are they raised 'bubbles'? Or solid bumps?

jonnydeppiwish!

Is it just oxidation/aging of the rubber due to the light?

leadlion

Bendy_House said:

The bumpy bits in the close-up pic, are they raised 'bubbles'? Or solid bumps?

Solid bumps.

Liverpool85

It looks like there are lots of little holes on the close up. Some group of 3.. does a cat climb over it I wonder? We have lots of similar little holes on a foam playmat our cats goes on 

[Deleted User]

Hi,

these coatings look good to start with, get you over a winter, then when sun hits them dry out and crack, maybe just an annual maintenance job, whatever it says on the tin.

leadlion

frugalmacdugal said:

Hi,

these coatings look good to start with, get you over a winter, then when sun hits them dry out and crack, maybe just an annual maintenance job, whatever it says on the tin.

You might be right. What a joke. I might just stick some roofing felt down along the parapet, since the rest of the flat roof is already felt and I know it will last a while. Could I use Black Jack roofing adhesive or similar straight on top of this ‘rubber’ crap?

leadlion

Or am I better off scraping it back to the bare masonry?