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Posted: Mon Jul 01, 2019 3:19 pm
by PerryJ
Hi All,

Recently had a Granite patio installed not by myself about 1 month ago now, the backs of the slabs were applied with a SBR bond however they were put in on a spot bed method,not full mortar bed.

The patio is stained so far because i used Joint It Dark Grey for the pointing i was told that this staining would take a good 12-15 weeks and plenty of sunlight to dissipate it which is not my primary concern.

So far there is no reflective staining however in the mornings when there is a bit of morning dew you can make out on at least on 5 slabs some spots but disappear further as temperature warms up later in the day.

Would a Wet look sealer do any good in hiding these spots also would the SBR Slurry help at all that was used to prevent it getting worse?.

I dont know how to put pictures up on this forum.

Thanks in advance.

Posted: Mon Jul 01, 2019 8:59 pm
by alrat
I'm not sure I can offer the answers you are after, but as the granite was installed with an SBR slurry on the back this should help protect against the reflective staining. I've a couple of granite flags with a void underneath as they were used to create a step, these can look damp after overnight moisture in the air, where as the rest of the slabs on a full mortar bed do not. I assume it's to do with the difference in temperature, air in the gaps (as per your spot bed) or something.

Is is silver (sesame) granite that you have? Did you seal it before jointing? This is vitally important, especially when using a dark brush in jointing compound on light slabs. Even if it's not a dark jointing compound the oils used in these products will soak in to the slabs and take quite a while to weather out, but should go eventually. Are the slabs stained all over or just around the joints from the 'Joint It' compound?

Posted: Tue Jul 02, 2019 3:56 am
by PerryJ
Hiya thanks for reply,

The Joint It compound was applied on unsealed slabs and they are stained all over not at the joins.

How do you post pictures what image hosting do you normally use I can show you on here as a picture would make explaining it a lot easier.

Thanks

Posted: Tue Jul 02, 2019 4:20 pm
by PerryJ
Pic 1 of patio pre jointing

https://www.dropbox.com/s....ng?dl=0

Pic 2 of patio jointing stain

https://www.dropbox.com/s....eg?dl=0

Pic 3

https://www.dropbox.com/s....ng?dl=0

Pic 4 possible reflective staining already?

https://www.dropbox.com/s....eg?dl=0

Pic 5 same are pictured the next day after

https://www.dropbox.com/s....eg?dl=0

Posted: Sun Jul 07, 2019 4:48 pm
by PerryJ
Anyone........ advice on the sealer......anyone please.....

Posted: Sun Jul 07, 2019 7:35 pm
by Vikinggroundworker
You may be able to get the stains out with smartseal residue remover.

regarding sealers - try the people at United Stonecare - very helpful.

Posted: Sun Jul 07, 2019 7:59 pm
by alrat
If you're not sure there's going to be a reflective staining issue, you should just wait and see how it turns out, don't be too hasty. The wet look sealer won't do anything to prevent the staining. Do you really want a permanent wet look?

Posted: Sun Jul 07, 2019 8:01 pm
by alrat
If you're not sure there's going to be a reflective staining issue, you should just wait and see how it turns out, don't be too hasty. The wet look sealer won't do anything to prevent the staining. Do you really want a permanent wet look?

Posted: Tue Jul 09, 2019 10:58 am
by Tony McC
I can see reflective staining in at least one of your images.

Unless the whole of the flag underside is primed with a suitable slurry, and then laid on a full bed, there is a risk of reflective staining. A primer alone will NOT prevent spot bedding marking the flags.

And a sealant would only seal-in the problem, not fix it.

Joint It, like so many of the one-part polymeric mortars, uses a doping oil to prevent curing of the resin coating applied to the fine aggregate. Fust which oil is used to dope will determine how badly any staining will appear to be. Some are pretty bloody awful, while others are barely noticeable, and, of course, the substrate has a huge part in how it all looks.

The good news is that most of these doping oils weather out in 2-24 weeks, so *that* part of the staining will, eventually, dissipate, but the reflective staining is more likely to be permanent.