How to seal a leaking planter box?

[mitch0816]

Hi All,

My apartment has a courtyard with brick planter boxes. The issue I have is that whenever I water the planter boxes, some of the water leaks out onto the concrete pavement and pools there and is staining and degrading the pavement.

I

I presume that the water is leaking through these cracks and so whatever waterproofing it had has failed.

I want to seal the planter boxes to stop this leaking.

If anyone is able to suggest solutions to this, it would be much appreciated. Is it possible to seal it from outside without having to remove all the soil?

Thanks for any advice you can give.

[MitchellMc]

Welcome to the Bunnings Workshop community, @mitch0816. It's terrific to have you join us, and many thanks for your question about sealing a planter box.

You could seal that crack with Sikaflex 11FC from the outside. That should help prevent water leaking out the crack. However, there needs to be some drainage from the garden bed, or you'll end up with a pond. If the bed wasn't filling up with water before, then it sounds like there must be some drainage somewhere, which is fine.

The repair to the crack would be best done from the inside, followed by an additional seal on the outside. But, given the bed is filled, it might be worth trying the outside first.

To apply the sealant, make sure the crack and surrounding grout joints are thoroughly clean and dry. Use a wire brush to remove any loose debris or dirt from the area. Once clean, you can apply the Sikaflex directly into the crack, ensuring it's pressed in deeply to fill any gaps. Use a putty knife or similar tool to smooth the sealant over the crack for an even finish. Leave it to cure for the recommended time on the packaging before watering again.

Please let me know if you have any questions.

Mitchell

[mitch0816]

Thanks Mitchell. Much appreciated!