Yer a genius if you can .....

[ToughButterCup]

 tell me which is the right way up for these please. Notice I'm only asking you all to decide which is the top side of any of the slabs I've just had delivered.

 

Because given that, even I can just about work out which face should be on the bottom

There are no indicators anywhere round the edge of the slabs.

This one (A)  Top - side ? [ more dimples]

 or 

 

This one (B) Top side?  [fewer dimples]

 

 

And because I'm a teacher, please when you respond, show your workings for more marks. And a biscuit if you agree with SWMBO. 😜

[MikeSharp01]

I vote for the dimples being the underside! Why - evidence - because the dimples are part of the manufacturing process and offer a key for the underside cement if used. The dimples are not big enough for the slabs to be indicator slabs that you might see at dropped curb edges on pelican crossings. The dimples are unsightly. 

[SteamyTea]

Dimples down.

It creates more surface to whatever it is bonding to.

 

Actually I don't have a clue on those council slabs, but when we made tooling for concrete slabs, the edges had a slight taper on them so the slab realised from the mould easily. The slightly small face became the top. That face could have any texture you liked on it. 

Those slabs look like they are stamped out, hence a texture on both faces.

Stamping, or high pressure moulding, allows for less water usage (just the correct amount), better filling of the tool, less waste, faster processing times  (minutes rather than hours) and a more homogeneous product that takes up less manufacturing space.

Edited 4 hours ago by SteamyTea

[ToughButterCup]

That's just exactly the problem both of you.

Both sides have dimples. Side A has more dimples than side B. 

 

Or in your words @SteamyTea, they are stamped out, but the stamps are dissimilar.

 

Why?

 

[TerryE]

4 hours ago, SteamyTea said:

Dimples down.

My vote as well . I believe it to act as a keying surface for the mortar bed; a smooth surface is more likely to shear, and the slabs to loosen. 🙂

 

Edited 28 minutes ago by TerryE