Exterior grouting with the wet weather.

[Jed2009]

Hi,
I've laid an external porcelain patio on a sand and cement bed with ultrascape priming slurry. It was layed just under 5 weeks ago. I am wanting to grout the patio but am concerned about doing it when it is wet/not fully dry I wouldn't be concerned if it hadn't been raining so much but there has been rain consistently over the last month and more in the forecast over the next week at least, is this something I shouldn't worry about as long as there is no water pooling in the joints?
When would you say it's safe to grout, would you wait for a number of dry days beforehand?
I have experience with tiling and grouting but sand and cement bed with porcelain tiles externally is a first for me and im aware drying times are significantly longer especially with current weather conditions.
Grout hasn't yet been selected so would be open to suggestions if there's a product that would work best in the conditions.
Any help/advice would be really appreciated.
Thanks.

 

[Dan]

You do want to wait for it to be at its driest possible. But cement cures by chemical reaction so would even set under water (small swimming pool repairs can be done without emptying for eg).

So clean it all out ready, then cover it with a tarp so water can run off it, and wait for a few dry days in a row and grout on the last then cover it again after sponging lots and getting the tile surface clean, and it should be fine the day after for any touching up from sunken grout or whatever.