How to repair patio concrete flaking?

[SamMac]

Hi Looking for advice on how to address this issue with front patio concrete (pretty sure, but it has a decorative layer of some kind over it)

Location: Front patio to left of door.

Issue: Compare pictures 1 and 2 – picture 1 shows were the top of the patio concrete looks to have been worn away over time and is now flaking (swept up plenty of little bits before photos whilst wearing mask of course) and wearing away compared to nearby intact are in picture 2.

Picture 3 shows another view of how its worn down beneath the main level and picture 4 more close up of the fraying bits.

It’s an uneven shape but roughly 30X15cm in area and depth varies but probably about 5mm at its deepest.

Causes: I’m guessing what has happened is water has gotten in there over time under the top layer (possibly due to water from pot plants nearby specifically) and worn it away and now in that section it is flaking it away and exposing underlayers.

Advice Requested: Any advice on how to patch /repair? I’m guessing some kind of fill then sealer (or possibly an ‘all in one product’)  but not sure what exactly. Ideally if it’s a product that might help avoid issues on the rest of that patio too that would be handy e.g. a recoat of something.

I’m hoping given its isolated to this section for now addressing now will prevent further spread.

Tools on hand: I currently have Dunlop 5kg Ardit Rapidset Repair Mortar(https://www.bunnings.com.au/dunlop-5kg-ardit-rapidset-repair-mortar_p0760262) so familiar (for a very occasional DIYer!) with that kind of thing, but as can be seen the coloring would be way off and noticeable. I also have 2 trowels (pointing one https://www.bunnings.com.au/craftright-150mm-pointing-trowel_p5960144 and a broad flat one https://www.bunnings.com.au/kango-200mm-gauging-trowel_p0098438 ), but obviously happy to obtain whatever product are best suited.

Thanks in Advance,

SammacPicture 4Picture 3Picture 2Picture 1

[JacobZ]

Hi @SamMac,

Is it possible to get a couple of photos from further back showing the overall picture?

From what I can see, I don't think there is a great option for repair because whatever material has been used is delaminating and breaking away from itself and the surface beneath. If you were to apply something over this, it would bond to the loose material, which wouldn't be stable.

Does it seem like there is a stable, concrete surface beneath this flaking material? If so, I'd say removing this damaged coating is going to be the starting point.

Without seeing the broader picture, I imagine your only real option is to grind back the surface and remove this decorative coating. 

You could then look at what coverings could be applied over the concrete, such as tiles or pavers, to create a more aesthetically pleasing surface.

I will assist further when we can see some broader pictures.

Jacob

[SamMac]

Thanks for taking a look @JacobZ . Picture 5 is more zoomed out with the affected area in yellow, picture 6 shows the 'edge' of the patio which might help assess what is beneath, I think its basically slate piece onto the mortar/Concreate of the patio itself.  I think this is a slate top layer patio based on some other threads on bunnings community e.g. https://www.workshop.bunnings.com.au/t5/Outdoor/How-to-repair-slate-outdoor-terrace-floor/td-p/25957.... Water doesn't seem to bead at all so any prior sealing layer seems long gone. 

[MitchellMc]

It does look like you’ve got a slate-tiled patio with quite wide joints @SamMac. Slate really needs to be properly sealed to protect it from the weather. Once water gets into the layers, it expands and contracts with temperature changes, which causes the top layers to pop off and loosen over time. Right now, you still have a few areas that are intact, like the bottom right-hand corner in your first picture above, and they seem to be in decent condition. The rest of the slate has been exposed and is starting to shed.

In this situation, there’s not really a patch that will hold long-term. If you want to try to prolong the life of the patio, the best approach is to chip out any loose material in those damaged areas and then apply a proper slate sealant. This will help prevent water from getting in and may slow the deterioration. Keep in mind that slate needs regular maintenance, so once the seal wears through, you’ll need to reseal it again, probably every couple of years.

The other option, as Jacob suggested, is to remove the slate and consider an alternative surface, like tiles or pavers. That involves chipping off the existing slate and preparing the concrete underneath, but it would likely be a more long-term solution than trying to maintain the already deteriorated slate.

Please let me know if you have any questions.

Mitchell

[SamMac]

Thanks @MitchellMc.  the overall patio is another meter and a half in the opposite direction that is in a similar OK state, it's just this one patch.

Would it be best to use a sealer like this https://www.bunnings.com.au/crommelin-1l-natural-finish-penetrating-sealer-and-water-repellent_p0356... over the whole patio including the degraded bit for consistency? Any specific cleaners to prepare the surface first? thanks! 

[MitchellMc]

Hi @SamMac,

You would need to use a slate sealer for slate and, yes, it would be best to coat the whole are for consistency.

Preparation is key before you start coating: 

Ensure your surface is thoroughly clean and free from oil, grease, dirt and moss prior to applying.
Clean the surface with Feast Watson Floorclean as per the product instructions
For new concrete and aggregate pebbles: 

Allow the surface to cure for approximately 28 days then treat surface with a 10% solution (dilute) of Hydrochloric Acid.
Apply Hydrochloric Acid using a brush or mop, allow the acid to remain on the surface for 15 minutes then flush off with clean water. 3. Allow the surface to dry completely before applying Slate and Pebble Sealer.

APPLICATION

Apply a minimum of two coats of Slate & Pebble Sealer using either a Feast Watson Floor Finish Applicator, brush, fine mohair or wool roller.

Mitchell