Patio Pointing turned to dust...

Hello,
We layed a small patio (2m x2m) over the weekend using a base of 6:1 sharp sand/concrete mix then brushed in a 4:1 mix of the same for the pointing, damping it all down after with the watering can.
The pointing pretty much hasn't seemed to set at all and just crumbles to touch - where have we gone wrong and more importantly how can we right it??
Cheers

my guess is you dry mixed and added water to the pointing in place washing out the cement.
now you have a sand mix with not enough cement.
scrap out pointing, mix mixture so it is wet and balls in your hand not runny.
repoint using a norrow stick to poke and pack between slabs.

Did you use sharp sand for pointing ? you need to be useing a soft sand without the grit also i would mix it a bit stronger say 3 and 1, also i am no great fan of dry pointing and find that pointing with a good strong mortar makes for a better job allround in my opinion. If you still want to dry point clean out as best you can what you have already done mix up a new batch with soft sand and add a small amount of water to your mix to give it a bit of bite (if useing a mixer dont leave it mixing for two long as it will begin to form lots dry balls of mortar) then brush it in and go over the joints with a trowel handle or something to push it well in ,then a light sprinkle of water , then give it time it could take a while to harden fully ie not over night. Hope this helps

bee said:

Hello,
We layed a small patio (2m x2m) over the weekend using a base of 6:1 sharp sand/concrete mix then brushed in a 4:1 mix of the same for the pointing, damping it all down after with the watering can.
The pointing pretty much hasn't seemed to set at all and just crumbles to touch - where have we gone wrong and more importantly how can we right it??
Cheers

Click to expand...

Can we quote this post whenever anyone asks about patio pointing?!?