how to paint outdoor mould prone patio?

[investor2009]

We have a concrete unfinished patio thats old as the hills and looks horrid. Sone parts get mpuldy each monsoon season. How do I prep and paint this?

Thinking paving paint. Plus, how long should the finish last? Considering moisture draw up under the concrete

 

[travelbug]

There is an anti mould solution you can put in paint. I can't think of the nmt of it though.

Speak to your local paint supplier.

 

[pinkboy]

If you're getting rising moisture through the concrete, then any painting will peel up prematurely. Stopping the moisture is virtually impossible unless you rip it up and start again.

How big is the patio?

pinkboy

 

[investor2009]

Its 200sq m all round the house. Total wrap around. In the wet season here it cqn bucket down for 2 weeks straight so different to southern states

 

[Pa1nter]

I agree with Pinkboy,
If the moisture is coming up from the bottom of the concrete,nothing will work.

On the other hand if its normal mould from excessive rain,Gerni it with a high pressure water blaster,if you still feel or see any mould,scrub with an anti mould solution and re wash "Dont paint over the mould" and when you are happy Wait for it to dry properly then paint it with a high quality paving paint (I prefer oil based for driveways but if its only walkways acrylic will do).You probably don't need a two pack but that's your choice.

You can add some anti mould to the paint but premium paints should already have it added,ask the store you buy the paint from or if in doubt phone the actual manufacturer.

 

[pinkboy]

I agree with Pinkboy,
If the moisture is coming up from the bottom of the concrete,nothing will work.

On the other hand if its normal mould from excessive rain,Gerni it with a high pressure water blaster,if you still feel or see any mould,scrub with an anti mould solution and re wash "Dont paint over the mould" and when you are happy Wait for it to dry properly then paint it with a high quality paving paint (I prefer oil based for driveways but if its only walkways acrylic will do).You probably don't need a two pack but that's your choice.

You can add some anti mould to the paint but premium paints should already have it added,ask the store you buy the paint from or if in doubt phone the actual manufacturer.

Further to Pa1nters good points, I would also etch it with Hydrochloric Acid to really kill off anything lurking just below the surface of the concrete. Just dilute it down with water a fair bit so it doesn't eat your concrete away.

I still stand by that if moisture is rising, then you will have some blistering of the paint over time, which may or may not be too bad aesthetically.

pinkboy

 

[investor2009]

Thanks guys. Will take this all into consideration

 

[investor2009]

Well we did the one already painted but badly chipped side over tge weekend. 2x ciats and it comes off easily in spots where previous paint wad really smooth and doesnt stick there. Paint proposed we can just paint over flaking paint. We knew it wouldnt be tge greatest finish but as long as its all a uniform colour. I think the bare concrete once washed should stick

 

[turfy77]

A couple of cheap and easy solutions:

1) Vinegar kills mould.
2) A bleach and water solution, say 1 part bleach 3 parts water will kill mould. Thats what I use when painting my outside eaves when they get mouldy. Obviously once you have treated it and killed the mould you will need to wash either the bleach or vinegar off with water, wait till its dry before treating/painting.

Your welcome!!!