How to prepare old tiled wall for painting?

[renorenoreno]

Hi team!

Would love your advice on how to prep my kitchen walls for painting. 

I've just had a wall knocked out in my apartment and a beam installed where the wall was. 

The beam has been covered in gyprock and then plastered over. It's super smoooooth. 

The wall next to it on the other hand has been rendered over where very old tiles were ripped off. 

This render was fairly rough to the touch but I've sanded it so it's now much smoother. But visually it obviously still has a very grainy look compared to the plaster over the gyprock. 

A) Can I paint straight over the new grey render? Or do I need to coat it in something first?

B) Is there a way to get the new grey render looking smoother? Concerned that the gyprock beam is going to appear overly smooth when painted compared to the walls.

Thanks so much

[EricL]

Hello @renorenoreno 

I propose looking at using the Gyprock CSR 20kg Hardwall Plaster it will produce a nice flat finish the same as the smooth section of your wall. However, just a friendly word of caution, if you've not done plastering before or are not familiar with rendering a fine finish. I suggest calling your plasterer back to have the rough section rendered smooth. It requires a high degree of skill and experience to render the wall flat, smooth and level. If it was a small section that was being patched, I would recommend giving it a go. But since it is such a large section, I would not recommend doing it as a first time D.I.Y. project.    

Let me call on our experienced members @Dave-1, @Nailbag and @DIY4Knuckleheds for their recommendations.

If you need further assistance, please let us know.

Eric

[Nailbag]

Hi @renorenoreno 

I agree on the recommendations on both the product to use over the render to make it smooth, but also to consider a plasterer to do this as its a highly skilled job.

Make sure you use a primer on the new plaster before painting.

Nailbag

[Dave-1]

Good morning @renorenoreno 

@EricL 's suggestions is also the way I would go. 

Having done a small amount of plastering and understanding how hard it can be to get right even after a few times, I went straight towards a professional installer to do the plaster that @EricL has recomended There is no harm in trying, maybe even try on a smller sheet first and see if you are happy with how it works. For something that will catch you eye everytime you walk past Id make sure you are happy.

Dave

[renorenoreno]

Okay thanks Eric great advice!

And just as a follow up - can I paint straight onto the concrete render if I decide not to make it smooth?

[MitchellMc]

Hi @renorenoreno,

You would need to undercoat the surface first with something like Dulux 1Step Prep Primer, Sealer & Undercoat 4L. If the surface is overly powdery, it would be best to use a specific sealer/binder such as Dulux 1L PRECISION White Sealer Binder.

Please let me know if you have any questions.

Mitchell