Wrong Sand - is it still ok for bedding mortar?

[ChrisE92]

Hi all!

im about to lay a 20m2 Indian sandstone paving set, and have my foundation and sub base all level and ready, but I’ve accidentally ordered the wrong type of sand and ended up with a bulk bag of 3mm grit!!

Would it still be ok to mix this 5:1 with my cement for a workable bedding mortar or should I try and return?!

 

Appreciate your thoughts..

[ToughButterCup]

@MortarThePoint will know.... 

My BM was fine about exchanging one  bag for another. 

[MortarThePoint]

1 hour ago, ToughButterCup said:

@MortarThePoint will know.... 

My BM was fine about exchanging one  bag for another. 

 

For bedding slabs I think you want sharp sand (check though) and I don't think your 3mm grit will fair well. I would get the bag swapped. The BM may charge a delivery charge, but you should be able to return the grit. Unless of course you can think of something else to do with the grit.

 

I don't know much about laying paving, but was surprised when I learnt how thick the bedding mortar should be. Something like 40mm if I recall correctly. Below is a video I have watched before on this. Don't forget the slope away from the house.

 

 

[Mr Punter]

I would try a sample mix and see how it is.  It would need a fairly thick layer.

[Temp]

Perhaps use it to level the lawn instead?

[Gus Potter]

On 14/06/2023 at 23:36, ChrisE92 said:

Would it still be ok to mix this 5:1 with my cement for a workable bedding mortar or should I try and return?!

 

7 hours ago, Mr Punter said:

I would try a sample mix and see how it is.  It would need a fairly thick layer.

I think you will be ok. Buy some mortar plasticiser and do a trial mix with the grit at 4 to 5:1. Don't use fairy liquid as an alternative plasticiser.

 

Much will depend on the weather, how fast you can go laying and whether you have a mixer or are hand mixing on a board. Give it a go and see how workable it is.

 

If you find it is not that workable buy some soft builders sand and mix that in to the grit as the soft sand has the fines content. You won't need much soft sand.

 

In some ways you want your bedding to be a bit porous as it is less frost succeptable so don't over do the soft sand content.

 

2 hours ago, Temp said:

Perhaps use it to level the lawn instead?

Any left over then follow @Temp advice.

 

[Dave Jones]

just order sharp, when they deliver it they will have space to take the grit back. Not worth messing about with.