How to paint textured rendered walls & plasterboard ceilings – Do I need primer?

[MarlieBeena]

Hi Bunnings Workshop Community 

We’re getting ready to paint a room in our 1950s double brick home for the first time, and I’d love some advice before we get started.

The ceilings are plasterboard, and the walls are double brick with what looks like a plaster render that has some texture to it (will share a photo for reference). Our plan is to clean everything first using sugar soap wipes. Note the image shown is the walls pre-patching and filling which has been done now! hopefully this pic is useful to see what the texture looks like. 

My main question is:
Do we need to apply primer or undercoat to the textured render walls before painting?
I’ve read mixed advice online and wasn’t sure if the texture or age of the render makes a difference. We're hoping for a long-lasting finish and don't mind that the textured wall is there. 

Thanks so much in advance 😊

Sophia

[JacobZ]

Hi Sophia (@MarlieBeena),

It's a fairly simple answer that I'm going to give.

Yes, after cleaning with sugar soap, please apply a primer such as this Dulux 1Step Prep Primer, Sealer & Undercoat before painting.

Primer acts as a binding layer, helping the paint adhere properly to the rendered surface. Textured render often contains porous materials such as sand and cement, which can absorb moisture unevenly. Without a primer, the paint may be absorbed too quickly into some areas and sit loosely on others, leading to patchy, inconsistent coverage and an uneven finish. Primer evens out the absorption rate, allowing the topcoat to dry uniformly and achieve its true colour and sheen.

It is a simple addition that will ensure your paint job is long-lasting and to a professional standard.

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

Jacob