How to seal old besser blocks?

[niva]

Hi, I'm needing to waterproof and paint over old bessar blocks in the laundry of my parents house. Built in the early 80s and painted late 80s with regular outdoor paint - no other sealing on walls. Some waterproofing done where walls meet floorsome time ago. During heavy rain still leaking in some places. Seems like effloresence on blocks where water has run down (when gutters not cleaned and overflowing) see picture.

What do you suggest as a sealer? Or should I paint first then seal?

Do I waterproof / seal both exterior and interior? Some of the interior walls are also painted but not all. I want to paint the whole interior white.

And what product do you suggest for cleaning effloresence prior to sealing or painting? 

And, last question (!) - what product to seal cracks in concrete?

all advice much appreciated. 

thank you 

[JacobZ95]

Hi @niva,

I’d start by cleaning the area thoroughly with Cromellin 4l Efflorescence Remover

and a good stiff bristled brush such as Sabco Bamboo All Purpose Heavy Duty Scrub.

I’d then have a good read through this thread; How To Paint Besser Blocks as it provides some great info and answers.

If this doesn’t answer everything, please reach out. 

Jacob

[EricL]

Hi @niva 

Welcome to the Bunnings Workshop community. It's sensational to have you join us and thanks for sharing your question about painting and sealing Besser blocks.

It's great that you've received excellent advice from @JacobZ95. Just to add to the suggestions made, I recommend using Selleys 415g Brick And Concrete Sealant to fill in any cracks. 

Is water passing through your Besser blocks and making its way inside? Are you having condensation problems inside your wall? If you are, these issues will need to be addressed first before you begin painting your wall. 

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

Eric

[niva]

thank you - thanks for the link to that thread.

[niva]

Hi - thank you - that Selleys product is perfect.

No condensation, just in heavy rain, wall is near a gutter which hadn't been cleaned and hoping the leaking was from overflowing gutters. Looking at a few things to fix!

thanks for your advice that's great.

[EricL]

Hi @niva 

If you find any other anomalies or symptoms in your masonry wall, please don't hesitate to post a question.

Eric