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I noticed some water seeping down from the balcony, as this is above our garage. Luckily, this is the outside part of the garage.
When inspecting the balcony, I noticed that there are cracks in the grout. We are in a wet weather period, which is expected to last another week. Images attached show the general set-up and a close-up of the cracks.
Oh, and to make things worse, we have issues with how our gutters are, in that the overflow valves were installed too low, which means in heavy rain, the pressure from this spout is quite high and likely the cause of the issue. I attached an image demonstrating this.
I am looking for a solution I can implement now to mitigate the issue during the coming wet week, and until I can regrout and seal.
I had looked at weather tapes, but worried about removing these.
I had also looked at sealants, which as Sellys All Clear, or Sellys Storm Sealant.
Just wondering what advice you may have for a good solution, ideally I would like to be able to grout in wet weather, as we do get small breaks. but the material will not be dry.
I currently have the following products on hand... I assume I would need to purchase something else,. But I wasn't sure if anything I already had could work, I feel I keep buying new products.
- Westbuild 9kg Fast Setting Mortar. (I had used to patch render in a large area)
- Pollyfilla Exterior render
- Sellys no more gaps bathroom
- Dunlop 250g White Ready To Go Tile Adhesive And Grout
- Nordsjo Light and smooth super filler.
Looking forward to your advice. 
Hi @MissJess,
Start by cleaning out the cracks and removing any loose grout that’s likely to fall out anyway. Dry the area as best you can, then tape off the surrounding tiles and wall to keep things neat. I’d recommend using Sikaflex 11FC in grey—run a bead along the full length of the joint, smooth it off with a wet finger, and remove the tape straight away. It forms a good flexible seal and should hold up well even with some movement in the surface. It doesn’t take long to skin over, so you only need a few hours of dry weather for it to set properly. While you could experiment with some of the products you already have, most won’t perform well in damp conditions or offer the same flexibility and adhesion as Sikaflex. You may find that this ends up being a long-term solution, since sealing joints with Sikaflex is actually a standard approach in areas prone to movement.
As for the spout, ideally there should be a proper gutter and downpipe system directing water into stormwater drainage, rather than allowing high-pressure flow onto the balcony. Also keep in mind that balconies are required to have a waterproofing membrane, so if water is making its way through a crack, it could mean the membrane has been compromised or water is tracking around it. If there’s no visible floor waste or drainage outlet on the balcony, that could also be contributing to the pooling. It might be worth checking whether the balcony is properly graded and has a functional drainage point.
Please let me know if you have any questions.
Mitchell
Hi Mitchell
I’d cleaned the balcony since posting my question and had thought I’d have a couple more hours of sunlight, I purchased the sealant and safe to say I failed… I’ve never been particularly good with plastic like sealants (over did it and pulled of tape too early) and I think my initial picture didn’t properly demonstrate the size of the issue with the gaps, in that they are not at the connection but also on base of that connection.
Additionally it’s all very hard, not a typical grout that you could remove, so despite looking cracked and loose it’s cracked but very stable.
My failure was also helped by the rain coming early.. so I quickly removed what I could.
I think I need to fix the gaps before sealing and either need to practice a lot or try a more forgiving method of sealing.
It’s extreamly wet atm, but if I get a break in the next couple of days can I use any of my existing products (e.g exterior render) to fill the gaps, both in wall and floor ahead of sealing (thinking a clear membrane, non plasticy sealant or paint might me more my skill level).
Or to save the painting I’ve fixed in the outside garage, which is where this hits, should I just purchase tape for a temporary option?
Regarding the balcony, there is a drainage hole, the previous picture didn’t show this well, and the issue appears to be just the edge, which is coming around the flashing underneath, so right at the edge (1-2cm).
I am hopeful if I can plug these it should be fine. Also now all cleaned hopefully drainage issue can be avoided.
update, would something like these work?
Hi @MissJess,
Thanks for the extra details, and I’m sorry to hear that the sealant application didn’t go as planned, especially with the weather working against you. Sikaflex is still your best option for a long-lasting and flexible seal in this kind of situation, particularly where movement and moisture are involved. If the gaps are larger than expected and the surface is tricky, it might be worth considering getting a handy person to help, just to ensure a clean and effective finish. That said, if you'd like to tackle it yourself, don’t worry — it’s very common to find this type of job fiddly at first.
To make things easier, make sure the surface is clean and as dry as possible. Apply painter’s tape to both sides of the joint to define your line and help get a neat finish. When applying Sikaflex, you can run a damp finger or a soapy tool over the bead to smooth it out before it skins over. If you do overdo it again, don’t stress — you can trim any excess with a sharp blade once it’s dry.
As for temporary fixes, using something like exterior render probably won’t be flexible enough and may crack again. And while tape might offer some very short-term protection, it won’t hold up to ongoing wet weather.
Since the cracks are stable and the issue is localised near the flashing and drainage edge, once sealed properly, it sounds like you'll have the problem under control. Just try to catch a break in the weather and go for a proper Sikaflex application — it’ll be worth it in the long run.
Mitchell
Ok, challenge accepted.
Hopefully my next post will be picture of a successful job.
Sorry @MissJess. Have a read through of these two guides, which should help with the application: How to apply silicone sealant and How to fill a joint in a concrete slab.
If doing one continuous bead across the whole span is a bit tricky, then you can even apply a small amount of the Sikaflex to your gloved finger and wipe it into the cracks. As long as you can fill and bridge the cracks, it will reduce the amount of water getting into them. Later, you can do a full bead across the whole span.
Mitchell
