How to waterproof balcony?

[dennismorton]

Hi Folks,

I have an issue with my balcony. Its full exposed and when it rains I can see water leaking down from one side.  Its got some moss and stuff growing on the edges and the silicon sealing is coming off. I am thinking of doing the below.  I am completely new to this type of work so any suggestions is appreciated

1)  Clean and scrub and get rid of moss.  Use something like this "30 Seconds 2L Outdoor Cleaner Concentrate"

2) Get rid of all the old silicon sealants.

3) use this "Selleys 300ml 720 Translucent Exterior Neutral Cure Silicone" to reseal .  Is it good enough or what is a good sealant for outdoor use?

Question
1) Should I use something like  "Dunlop 250ml Grout Sealer"?? and/OR "CPC 220ml Shower Plug Sealant" for extra protection.

2) Grout seems strong and intact, but I can see small gaps, see pics.  should I remove it or some grout sealer will be enough?
3) Are grout inherently water proof or do we need to apply like "Dunlop 250ml Grout Sealer" to make it water proof?  How is it done in bathrooms?

Any other tips and recommendation greatly appreciated.
Cheers.

[JacobZ]

Hi @dennismorton,

Thank you for your post and welcome to the Bunnings Workshop community, it is fantastic to have you with us.

Cleaning the grout with the 30 Seconds Outdoor Cleaner Concentrate is a great place to start. I'd suggest using this in conjunction with a Sabco Bamboo All Purpose Heavy Duty Scrubbing Brush will do a great deal of good in removing the mould and mildew.

Once the grout is clean, you can assess the condition of the existing grout. In the image you've uploaded, the grout looks to be fairly good, and if that is the worst spot, I don't think there's a need to replace it. If you find any sections that are flaking and easily move, you may need to remove them and add some new grout. You can use How To Refresh Tile Grout as a guide on this.

Grout is not inherently waterproof. It is water resistant, but not waterproof. This is why tiled areas often need a waterproof membrane beneath them to act as a final layer of defence that sits behind the tiles and grout. 

With this in mind, adding a grout sealer such as the Dunlop 250ml Grout Sealer will certainly help to maximise water resistance, which will in turn reduce the growth of mould and mildew. The Dunlop grout sealer is in a great easy to use package, but depending on the size of the area, it may be more cost effective to use something like the Betta TileCare 1L Tile & Grout Sealer.

Let me know if you have any other questions.

Jacob

[dennismorton]

Thank you @JacobZ .