How to remove black barrier on ceiling?

[Robot]

 

70s apartment. Previously popcorn ceilings, now bare concrete. We want to paint the walls and leave the ceiling bare, but around the edges is this thick layer of black stuff... Maybe waterproof barrier? I Tried cutting some of it back and then wire brushing

 

the residual black tar like stuff off of the ceiling but it doesn't come off very easily.

We need to find a solution to either;

Have the stuff removed so the roof is back to bare concrete or

Can we paint over it and effectively have some kind of painted cornice

[EricL]

Hello @Robot 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your ceiling.

Black tar substances in joints and corners are generally an indicator of water proofing or sealer of some kind. I propose leaving it in place then painting over it. If you are re-covering the ceiling or re-rendering it will cover it up along with the installation of the cornice.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

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

Eric

[Nailbag]

Hi @Robot 

I would agree with @EricL that this appears to be some form of waterproofing barrier so you will need this as is. Your could consider some form of timber/metal trim around the external edges to cover it, and then apply your preferred finish.

Nailbag

[Dave-1]

Good Evening @Robot 

Same as both @EricL and @Nailbag  Plus I will throw in it could be expansion foam of some kind. Cornice or edging could cover it nicely. You could go for a square box type cornice to match a straight painted ceiling. 

As to removing the excess, whatever way you are using I would continue, small bit by small bit. 😕 Not a great answer but I think it could make it llook quiet nice.

Dave

[Robot]

Thanks for the reply. It's definitely a waterproofing layer that goes through the brickwork. I was trying to remove the excess that sticks out into our apartment because we wanted to try and go without cornices and just go painted wall bare concrete ceilings.

Since it's such a pain in the butt to get rid of, I've tested a section with some primer and I'm going to paint over to see what it looks like/ whether or not the black stuff likes being painted. 

We're now considering painting a cornice instead of actual physical cornices. Are we mad?

[EricL]

Hi @Robot 

At this stage of your renovation, every idea is open to consideration. I recommend giving it a go and see if it will pass inspection.

If you need further assistance, please let us know.

Eric