Slate patio with what grout?

Well there is only one way to grout any patio ,slate ,or paving slabs ,and that’s to mix a perfect blend of soft sand and cement ,and if you want white then use white cement ,then the job starts using a trowel you put the cement into the joint ,then you need to push cement down in the joint then finally at the right time you can point cement up to a perfect finish that will not crack or allow weeds to grow ,every patio we have done ,was and still will be grouted exactly as I described ,and in 15 years we have never been called back as grouting has cracked or different colours etc ,when patios are grouted in this way the grouting becomes part of the patio and even adds to the overall look of patio ,the problem is that most people don’t know what pointing should look like as people brush dry mix in that’s useless then there is all these new products in drums ,again in my opinion look a mess compared to the correct way ,all those other ways you can grout patios are all time saving get the job done as quick as possible ,that has never been KLPP way our way is do the job correctly and exactly as it should be done very best regards graham KLPP

hello, for an outdoor patio i don't think "grout" is the right product, you'd want a more porous substance like simply using sand on its own. If you want a "grout" try using pure cement alone. i certainly would not consider white, it will be dirty in a day.