How do you prepare and paint Besser block walls that are in your lounge room and kitchen? These blocks are bare having never been painted before. I believe when the blocks were created they put a colouring through the mix?
Hi @leanne71777,
Welcome to the Bunnings Workshop community, it is wonderful to have you with us.
With bare besser block walls, the key is good prep before you get into painting.
Start with a thorough clean to remove any dust, dirt, grease or loose material, especially in kitchen areas where grease is more likely. Give them a good scrub with some hot water and sugar soap, then allow the surface to dry completely.
Next, check over the mortar joints and blocks for any gaps, cracks or rough areas. Patch these up with some generic mortar mix such as this https://www.bunnings.com.au/dingo-10kg-mortar-mix_p0760516 . You can use a https://www.bunnings.com.au/kango-10mm-tuck-pointer_p0098441 to press the mortar into the areas where it is needed. You are aiming to have as even a surface as possible before moving on. You can sand and scrape back any high spots if needed, then allow everything to cure for at least 24 hours.
Once everything’s clean and patched, apply a quality primer such as https://www.bunnings.com.au/dulux-4l-1step-prep-primer-sealer-undercoat_p1370234 . This step is super important as besser blocks are quite porous and will soak up paint if not sealed properly.
After priming, you can go ahead with your topcoat using a good quality interior paint such as Dulux Wash and Wear in a colour and finish of your choosing. You'll want to apply at least two coats, allowing a minimum of two hours between coats.
Let me know if you have any further questions.
Jacob
HI Jacob,
With regards to cracks, gaps, holes etc - do they NEED to be filled? The bricks has millions of tiny holes in them (porous as you mentioned), is it essential that the primer completely gets in and fills these holes? Is the aim that the mortar and the primer ensure the surface is 100% completely sealed?
I will be honest, in the loungeroom, I started work BEFORE contacting you and now am worried. I brushed the walls down to remove dust and applied a 3 in 1 primer, sealer, undercoat. I painted over cracks, which you can still see. And can still see the little holes. I was reading somewhere about mold? What are the implications if I leave it as is?
Kind regards
Leanne
No, those cracks, gaps and tiny holes don’t need to be filled unless you’re aiming for a perfectly smooth, cosmetic finish. What you’re seeing is just the natural porosity of the brick, and even with a primer/sealer, it won’t completely fill every tiny hole, and it’s not really designed to. The goal of a primer is to seal and stabilise the surface so your topcoat adheres well, not to make the wall 100% smooth or airtight.
It’s completely normal that you can still see some cracks and the small pores through the coating as those would only disappear if you used a filler or skim coat beforehand.
As for mould, there’s no need to be concerned unless you already had a moisture or mould issue in that room. Leaving the surface as it is won’t cause mould on its own. Mould is related to moisture and ventilation, not whether tiny holes or hairline cracks were filled before painting.
So in short, there aren’t really any negative implications with what you’ve done, and it just comes down to appearance. If you’re happy with how it looks, you can absolutely leave it as is.
Please let me know if you have any questions.
Mitchell
Thank you both so much for your advice, and Mitchell - I can now breathe again haha! I am not looking for perfection (just a neat paint job really) and as far as I am aware there is no mold issues in my place. I really appreciate and will continue with what I am doing and try to enjoy the process 😂
