building sand for mortar

Hi

My neighbour had some paving slabs laid 6 months ago. The tradesmen had a jumbo bag of soft sand delivered for mixing up the mortar to lay the slabs on. When the job was done there was still a quarter of the bag left and it has been sat in his driveway since.

I'm going to lay some block paving for a path in my garden and wondered if I could use the remainder of his soft sand to make up some mortar for the edge units? I'm going to lay the blocks on sharp sand but the edge units will be bedded and haunched with mortar.

He's happy for me to have the sand but before I commit to taking it I wanted to check if it will be any good? Its just been sat on his drive in the bag it was delivered in without any protection.

Cheers!

The stuff goes off but can be reconstituted by washing it thoroughly then sieving it before drying for 48 hours in the oven.Afterwards the grains just need a quick polish with a clean microfibre towel.

I take it there's no problem then!

Although now i'm being told the edge units should be bedded in concrete, not mortar, using gravel and sharp sand (6:3:1) so may be of no use anyway

You can happily use up building sand to make concrete.

As you know don't use it to lay on but its fine for concrete.

You might benefit mixing in some coarse sand, soft building sand does tend to crumble.

are you filling the base work in with hardcore if soo just chuck it in with that then whack the lot then use sharp sand for the lot