Using sealant to stick loose patio flags down
Discussion
Hi all, last year I laid a patio of approx. 45m2 in my back garden. Did it all properly on a compacted sub base and a 4:1 bedding mix. However, a small handful of flags are loose due to the bedding not bonding to underside of flags properly. Seems I forgot to slurry a handful or they've blown due to water getting into voids (did try to avoid this).
Since it's only a handful and this is a very low traffic area only used during the summer months, and the bedding itself is absolutely solid, I'd like to avoid breaking the concrete and re-doing unless absolutely necessary. With this in mind, I've been looking at some alternative ways of approaching this, and I've seen mention of using waterproof sealant/grab adhesive type products to refix the flags.
Some of the products I've looked at so far:
CT1 - seems a strong contender, but pricey and seems to be pushed by a cult engaging in dubious practice.
OB1 - some suggestion this is a good alternative to CT1 and cheaper too.
Fix All - seems to fit the bill.
I've also seem some of the expanding foam type products suggested, but in my experience you always gain at least a couple of mm as it has to expand somewhere and the flags are already at correct levels.
Anyone with any experience of this?
Since it's only a handful and this is a very low traffic area only used during the summer months, and the bedding itself is absolutely solid, I'd like to avoid breaking the concrete and re-doing unless absolutely necessary. With this in mind, I've been looking at some alternative ways of approaching this, and I've seen mention of using waterproof sealant/grab adhesive type products to refix the flags.
Some of the products I've looked at so far:
CT1 - seems a strong contender, but pricey and seems to be pushed by a cult engaging in dubious practice.
OB1 - some suggestion this is a good alternative to CT1 and cheaper too.
Fix All - seems to fit the bill.
I've also seem some of the expanding foam type products suggested, but in my experience you always gain at least a couple of mm as it has to expand somewhere and the flags are already at correct levels.
Anyone with any experience of this?
Edited by NiceGuyEddie on Tuesday 31st March 22:12
Gorilla Glue, would you believe!!
https://youtu.be/JGulzx_di1g?si=ZamWWWVLWFGjImf8
I was very sceptical about this and tried it last summer in two areas, one light traffic, one heavy traffic - our main pathway to the front door.
In the light traffic area it has worked an absolute treat, still solid after a year. It was fine for a few months in the heavy traffic area but then failed again so I bit the bullet and completely re-bedded a couple of pavers, which wasn't as difficult as I expected it to be.
https://youtu.be/JGulzx_di1g?si=ZamWWWVLWFGjImf8
I was very sceptical about this and tried it last summer in two areas, one light traffic, one heavy traffic - our main pathway to the front door.
In the light traffic area it has worked an absolute treat, still solid after a year. It was fine for a few months in the heavy traffic area but then failed again so I bit the bullet and completely re-bedded a couple of pavers, which wasn't as difficult as I expected it to be.
An adhesive PU foam like https://www.toolstation.com/soudal-soudabond-easy-...
You squirt it on, leave it to expand (though it is low expansion anyway), then push on whatever you want to bond. It will squish down very flat where necessary. Works really well. Meant for sticking boards to walls or building blockwork so paving will be easy.
Can take a bit of getting back apart if you need to!
You squirt it on, leave it to expand (though it is low expansion anyway), then push on whatever you want to bond. It will squish down very flat where necessary. Works really well. Meant for sticking boards to walls or building blockwork so paving will be easy.
Can take a bit of getting back apart if you need to!
Regarding the Gorilla glue, that slight tap with a wooden wedge at the end ruined it for me, it looked pretty good until it just peeled off. I would use a thin bed of tile adhesive on both surfaces. If you do use PU glue get a litre bottle of Egger that is used on flooring, it will work out cheaper if you need a lot.
wolfracesonic said:
If you have any SBR left from last time, just make up a slightly thicker slurry and use that; it will be thin enough not to alter the height.
+1 for this method! Had a couple of areas where the mix was too dry on my patio project last year (and the sbr slurry priming had seemingly dried too) and had the same issue.
Lifted SBR slurry back down, and you’d never know, rock solid.
Would be weary about the longevity/ unwanted height building potential as mentioned of anything else
Some really interesting replies and suggestions, thanks all.
Regarding SBR slurry, I certainly have enough left over but I want to avoid the mess and I've heard it's not a very long lasting fix.
I've actually used the low expansion foam adhesives before to hang plasterboard with great success. However, there was a small amount of expansion which is just the nature of the product. And also, while being water repellent, it isn't waterproof, and I would be concerned about water freezing and expanding. I'm also not sure how well it would react to chemical cleaning, should I ever bleach the patio. Same goes for Gorilla Glue which I believe works along similar lines and conditions. I've seen the YT video and I wasn't impressed with how easy it separated with a wedge.
I am still leaning towards a strong adhesive sealant. Stixall for example isn't rated for permanent immersion in water, whereas OB1 and CT1 are. Of the two, I would probably go for OB1 as it is significantly cheaper and more or less the same product created by the same team from what I can gather.
Regarding SBR slurry, I certainly have enough left over but I want to avoid the mess and I've heard it's not a very long lasting fix.
I've actually used the low expansion foam adhesives before to hang plasterboard with great success. However, there was a small amount of expansion which is just the nature of the product. And also, while being water repellent, it isn't waterproof, and I would be concerned about water freezing and expanding. I'm also not sure how well it would react to chemical cleaning, should I ever bleach the patio. Same goes for Gorilla Glue which I believe works along similar lines and conditions. I've seen the YT video and I wasn't impressed with how easy it separated with a wedge.
I am still leaning towards a strong adhesive sealant. Stixall for example isn't rated for permanent immersion in water, whereas OB1 and CT1 are. Of the two, I would probably go for OB1 as it is significantly cheaper and more or less the same product created by the same team from what I can gather.
NiceGuyEddie said:
Some really interesting replies and suggestions, thanks all.
Regarding SBR slurry, I certainly have enough left over but I want to avoid the mess and I've heard it's not a very long lasting fix.
I've actually used the low expansion foam adhesives before to hang plasterboard with great success. However, there was a small amount of expansion which is just the nature of the product. And also, while being water repellent, it isn't waterproof, and I would be concerned about water freezing and expanding. I'm also not sure how well it would react to chemical cleaning, should I ever bleach the patio. Same goes for Gorilla Glue which I believe works along similar lines and conditions. I've seen the YT video and I wasn't impressed with how easy it separated with a wedge.
I am still leaning towards a strong adhesive sealant. Stixall for example isn't rated for permanent immersion in water, whereas OB1 and CT1 are. Of the two, I would probably go for OB1 as it is significantly cheaper and more or less the same product created by the same team from what I can gather.
The makers of OB1 have just lost a court case started by the makers of CT1. Apparently the sales teams at OB1 (Siroflex) often fed the line that it was made by the same factory to the same formula etc, not true according to CT1 and the court.Regarding SBR slurry, I certainly have enough left over but I want to avoid the mess and I've heard it's not a very long lasting fix.
I've actually used the low expansion foam adhesives before to hang plasterboard with great success. However, there was a small amount of expansion which is just the nature of the product. And also, while being water repellent, it isn't waterproof, and I would be concerned about water freezing and expanding. I'm also not sure how well it would react to chemical cleaning, should I ever bleach the patio. Same goes for Gorilla Glue which I believe works along similar lines and conditions. I've seen the YT video and I wasn't impressed with how easy it separated with a wedge.
I am still leaning towards a strong adhesive sealant. Stixall for example isn't rated for permanent immersion in water, whereas OB1 and CT1 are. Of the two, I would probably go for OB1 as it is significantly cheaper and more or less the same product created by the same team from what I can gather.
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