Dry Pouring Cement Sharp Sand

[Dave1UK]

So I've seen and heard of dry pouring cement (YouTube in USA mainly) on its own to make things such as small concrete patio etc.

Asides of the fact what the right way to do it is/whether structurally it would be as strong etc.

Would dry pouring a cement/sharp sand mix work/be the same concept? Thickness would be 80mm base.

I would dry mix the sharp sand with cement, lay it/level, go over it with a compactor and then water/sprinkle the area repeatedly every hour or so.

I am a complete amateur, in theory this sounds easier to me rather than laying and levelling a wet mix for a bigger area? Easier in regards to less to go wrong/I don't have to rush it.

 

[CountryFan]

Iirc I was told by someone to do it dry and let the rain wet it and tbh can’t remember which method I used when laying my own, might have been wet mix but in stages, eg 2 flags, remix and another 2 flags.

 

[Munroast]

I suspect it will be very weak, and a heavy person walking on it would break it up

I have laid slabs on a dry mix and on the occasions when I have lifted these slabs years later, it is very easy broken up (which is fine for stuff under paving slabs, but pretty crap if it was your finished screed

 

[Dave1UK]

I suspect it will be very weak, and a heavy person walking on it would break it up

I have laid slabs on a dry mix and on the occasions when I have lifted these slabs years later, it is very easy broken up (which is fine for stuff under paving slabs, but pretty crap if it was your finished screed

I think that the previous owners done this on our patio as there are what looks like cement "blocks" under our flags, the blocks are about 60mm thick and it's pretty hard stuff from the top and strong but if you lift it/break into it sideways it starts to crumble.

Thing is there is about 100mm deep of this stuff and a lot of it is loose, looks like they just done sections here and there rather than the whole area consistently.

I would rather not dispose of this and bring in something new as would take more work than for me to basically break it all up into small chunks, thinking off adding more cement, mix it in properly and then level it all, wet it and then relay the slabs on top.

 

[Donkmeister]

Normal concrete laid this way never cures properly. Strength is very low and you find the concrete in the middle is still powder. Bite the bullet and rent/borrow a cement mixer!

There is a concrete patch product made for this approach, though. I used it a year back, bought from either Wickes or B&Q. The aggregate is really small, like pea gravel. You chuck it in the hole, screed it out, ramp it and barely wet it with a watering can to set it up then keep watering it once it's done the initial cure.