Builders sand used under slabs

[Jo443]

Hi

I have just finished building a small raised patio area.
I was recommended by a handyman I know that I could lay a sand base and then just sprinkle some cement on before i laid each slab (400mm x 400mm) for stability.

We laid a base of hardcore and then just about 1cm of sand, flattened it and then sprinkled some cement powder on before laying the slabs.

However just realized that we have made a mistake insofar as we used builders sand rather than sharp sand for the base above the hardcore.
After some reading I can see this was obviously the wrong thing to do. What I want to know is if we need to take all the pavers up and relay or if it will likely be fine. Im hoping that because it was just a thin layer over hardcore it wont be a problem??

After reading through articles I can see we have clearly done it wrong so I am not trying to find out if this is a viable method. Just wondering if it will likely be okay or if it all needs redoing? Thanks

 

[Ian H]

It might have worked if you gave the sand and cement a proper mix, never heard of the sprinkling method.

 

[Jo443]

Recon its advisable to lift them and relay it?
There's going to be a shed sat over most of it so if it needs changing then I will do it before the shed goes down.

 

[23vc]

Doesn’t sound like a good method to me, I’ve always slabbed over compacted hardcore using a sharp sand wet mix. Then again if there’s a shed going to be sat on it, I doubt it’s going to go anywhere as it’ll have a consistent static weight on it. It’s the ones without the shed on that might cause an issue

 

[catlad]

Normally for foot traffic I would mix sand and cement mix 1 to 4 ratio ish. One spot in each corner and then when you have have laid a few level with the silent judge.

 

[Jo443]

I had hoped that the ones under the shed would be fine. I might just lift the few that lead up to the shed and replace that with sharp sand and then just leave the rest.

Its a lesson hard learned.

 

[^woody^]

There's nothing wrong with using building sand for slabbing in terms of performance.