"wet" marks around joints - Anyone know what these marks are?

[Patio-newbie]

Hello all,

I was wondering if anyone knew what these damp looking patches are around most of the joints.?

They look wet but they were laid and jointed over a week ago although we have only had a few days of good weather.

I have attached an image.

Really hoping a can pull on your expertise and experience to identify and possible resolve this the look really ruins the look of the patio.

the photo can be seen:

https://www.dropbox.com/sh....sa?dl=0

Many thanks in advance.

[Tom - Westminster Stone]

What have the slabs been pointed with? sometimes a jointing compound will hold moisture or some of the resin can temporarily stain the edges as pictured.

[Patio-newbie]

Hey Tom,

Thanks for your reply,

The patio is pointed Marshalls jointing compound (pretty sure its the 365 stuff).

It tipped it down last night and you cant see the stains while the patio is wet so I'm feeling its damp rater then oil or cement stain as I would think I would see this even when the patio is wet?

is this possible? could it take weeks for the jointing to try fully?

Thanks

[Tom - Westminster Stone]

Hi,
Yes it look as though you have granite slabs which are very dense so water will dry very quicky on the surface whereas water will permeate the 365 which will make the edges stay wetter for longer. I presume the edges eventually dry out when we have longer dry spells (not that we've had one of those for a while) when was the product laid?
Thanks

[Patio-newbie]

Hey Tom,

They have only been down for about 2 weeks, I'm hoping its just the jointing slowly drying.

it rained hard for about 4 days from the day they were jointed, then we have not had more then 3 dry days since.

They look awful, I really hope they dry out and are only taking so long for the first time as the jointing compound wont absorb water once its dried/cured.

Thanks

[Tony McC]

Tom is right: the jointing is acting as a reservoir for moisture.

It's not a threat to the paving, although there is a risk the jointing will green-up with algae and mosses over time. This can be controlled by using a basic weedkiller or a good quaility biocide.

The jointing medium remains permeable well into the long term, so this may become a familiar feature in your garden. There's a bit of an explanation here. It *may* silt-up over time, depending on just what has been used as a bedding material, and the visual impact become much less noticeable, but there is no guarantee.

It's not what you want to hear just now but it's minor issues such as this that make the case for a proper pemeable bedding material al the more compelling.

[Patio-newbie]

thanks for your response Tony,

I will just have to see how it goes, I watched the install closely and builder followed Marshalls recommendations for the base and install so I really hope this clears up otherwise I would have been better off using cheap stone rather then expensive Granite

Kind regards