Dry Grouting On A Patio

[zom414]

We had our garden done last month with decking leading to a patio. It all looks fantastic and the garden is now useable (it was on a slope before). Just got a question about the patio grouting though. The mixture they put in was powder form and just swept between the slabs. He told me that when it went wet it would then dry and harden out. It's now been over a month and it's still not set hard, it has formed a sort of skin but if you apply any sort of pressure it just breaks. There's also a problem with ants coming through the grout as well which they wouldn't be able to do if it was set.

I'd love to be able to clean the slabs too but don't really want to do anything till it sets as it will probably all just wash/brush away. I've spoken to the guy several times and he said he's now going to come and have a look at it to see what it's like. Is this the normal way that patios are grouted? Just thought a cement like grout would have been used. Also, whilst I'm here, what would be the best way to clean the patio? Is it ok to use a pressure washer with the patio/decking attachment?

 

[i_am_fubar]

Filling with dry mix is standard. Although it sounds like the mix was too lean.

Hopefully he'll see the error and correct it. But if it's requires new, then a dry mix of (and guys, feel free to correct me) 1 part cement, 4 parts soft sand as a dry mix. Sweep in, then give a gentle misting with a hose pipe.

Be sure to sweep ALL EXCESS away before soaking. The stuff will stain.

 

[WabbitPoo]

How many times do we have to say it? no No NO

Do not use a dry mix for slab pointing. Use a damp mix that will then set hard.

 

[noseall]

Brushed in pointing!!

What a load of old shi.....!

When will people learn.

 

[theoldun]

Let me be the first to correct you Mr Fubar. Sorry, the third.
Any one who uses a bone dry mix of sand and cement swept into the joints of a patio is a thief and robber for taking money under false prê tentices.
Cement is the binder and cement will not start its initial set until it comes into contact with water. The initial CaS and CaA set starts after 15 minutes. The initial set is 2 to 4 hours. The CsA secondary is 10 hours. The CaA secondary is 30/40 hours. None of this will happen unless hydration starts with the addition of water. The addition of water does not just mean sprinkling a drop on the top. End of story.
It has nothing to do with whether it is too lean, too fat, too strong too weak or purple with yellow spots. It is all down to hydration.
old un

 

[zom414]

Thanks for the answers. So, when the guy comes back what should I tell him I want it pointing with?

 

[theoldun]

We use 1 cement, 3 soft sand, and splash of admix. Sufficent water to be able to pick up handfull, mould into ball and it all holds together and does not break up and your hands do not come away wet.
Some use a 1 to 4 mix. We use 1 to 3 as it comes up with a bit more fat in it
We use a decent jointer instead of trowel.
old un.

 

[Thermo]

Filling with dry mix is standard. Although it sounds like the mix was too lean.

.

horse poo, as the others have said, any decent paver will use a damp mix, not dry mix brushed in and leave it to chance.