Fill gaps in outdoor garage steps

[Drich]

I've build some garage steps, and I'm ready to lay the pavers. The risers will consist of two 300x450mm pavers, and the top will be 4 square pavers. As you can see in the photo, there are some small gaps between the aeriated concrete blocks (these sit on top breeze blocks)

My question: Do these gaps need filling with rubble/mot/etc so I can lay the pavers onto a solid bed?

 

[Deluks]

No, it looks like the pavers will be well supported. Just ensure the pavers fall slightly away from the wall.

 

[Ivor Windybottom]

There's a chance the cement spots may eventually show through the paving surface...

Does it have a footing? It looks like the bottom step is built on the existing paving. If not then I'd be inclined to fill it with concrete to hopefully help it stay together, to compensate for it being built on topsoil.

...or perhaps making it heavier may make it more likely to sink?

 

[Drich]

Thank you for the replies - I ended up filling most of the gaps with some aeriated brick offcuts and other rubble.

@Deluks Yes, I did put a slight fall away from the wall.

@Ivor Windybottom I dug between 20-30cm for the footings and filled with compacted aggregate and a concrete base, so it should be okay. I laid the existing patio too, so I know the footings are decent there. That said, I didn't want to add unnecessary weight, hence the use of aeriated blocks.