How to prepare exterior wall with paint washing off?

[Annie45]

 

Hi,

I’m wanting to paint this exterior wall but I’m not sure how to prepare it properly as the previous paint washes off. I do not know what it got painted with but it seems to be only one coat.

I appreciate any advice.

Thanks.

[EricL]

Hello @Annie45 

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

It is a bit concerning if the paint on your wall is coming off due to water condensation on the surface. Can you please tell us a little bit more about this wall? Is it a retaining wall and is soil behind it? Do you have any clue why your wall is full of moisture and is sweating it off the surface? Is plumbing inside the wall? Is the soil in front of the wall muddy or has standing water around it? If you have any other theories why your wall is wet, please don't hesitate to tell us.

In its current condition the wall can't be painted or sealed for that matter. The source of the moisture must be discovered first and addressed. The wall has to be bone dry before any type of paint or sealer is applied to its surface. Painting it now will be a waste of material as it will not adhere properly and will just peel off.

Eric

[Annie45]

Hi Eric,

thanks for your reply.

The wall is dry. I was cleaning it with just plain water because I had the suspicion that it might just come off as I had paint before on my hand when I touched it. I think it might not have been undercoated properly, or the wrong type of paint has been used.

[JacobZ]

Hi @Annie45,

To me, this looks like old primer that didn't have paint applied over it and over time it has weakened and broken down.

My suggestion would be to give the wall a good scrub with sugar soap mixed with warm water using an Oates Long Handle Deck Scrub Brush. This should remove most of the weakened coat, which I believe is primer.

Once clean and sufficiently dry, I would suggest applying a new coat of primer such as this Dulux 1Step Prep Primer, Sealer & Undercoat. Allow it to dry for the recommended 2 hours before painting over with 2-3 coats of an exterior paint such as Dulux Weathershield.

Let me know what you think and if you have any further questions, please don't hesitate to ask.

Jacob

[Annie45]

Thanks for the suggestion, Jacob. I'll go with that.

Annie