Grouting patio slabs.

[conny]

I've re-laid a section of my patio with new 450 x 450 x 32 riven slabs and am now waiting for the base cement to set for 24-48 hours.

When I come to grout between the slabs, I have a depth of around 20mm by 10mm width to fill, (some of the base cement has squeezed up between the slabs). Can I fill the bottom half with a 10mm depth of kiln dried sand and then grout the top 10mm with a sand & cement mix, or should it be a full depth sand & cement mix?
(Reason being, I'm getting a bit low on cement and don't want to buy another bag if I'm only going to use about 1/4 of it. The rest would probably go to waste).

 

[Eccles]

Seeing as a bag of cement is only £7 in Wickes and it will keep for ever in a plastic bag ( I have some which is five years old and still good), why worry? You might want to do some repairs to that grout in a couple of years.

 

[conny]

Didn't know it would last that long if you plastic bagged it. On the bag I have left it has a 'Use By' date of 26-06-2023non it,
Assumed after that it would lose it's strength or something.

 

[John D v2.0]

The use by date is very pessimistic, and you can check it by just looking at it. I've been using some that's over 6 months out of date for bedding roof tiles.

After we moved in I found some cement in the damp shed in a plastic rubble sack and I used it for something, it was fine, it must have been minimum 5 years old more likely 15+. Just make sure you close the wrapper properly and if it's lumpy then don't use the lumpy bits.

If it's got wet it's no good, if it's been bone dry it's as good as it was when it was made.

 

[noseall]

I've re-laid a section of my patio with new 450 x 450 x 32 riven slabs and am now waiting for the base cement to set for 24-48 hours.

When I come to grout between the slabs, I have a depth of around 20mm by 10mm width to fill, (some of the base cement has squeezed up between the slabs). Can I fill the bottom half with a 10mm depth of kiln dried sand and then grout the top 10mm with a sand & cement mix, or should it be a full depth sand & cement mix?
(Reason being, I'm getting a bit low on cement and don't want to buy another bag if I'm only going to use about 1/4 of it. The rest would probably go to waste).

Use polymer fill. Good stuff as long as you tool it in. Incredibly easy to use especially the wet-fill. Truly successful (mortar) slab joints should be applied when laying so that the pointing is attached to the bedding material.

 

[conny]

Did it early yesterday morning before the bedding had fully cured and had enough sand & cement to complete fully.
It wasn't the cost of buying more cement if needed, just the waste of what would be left over and the fact it's a 25 mile round trip to the local town to get it.