How to level an existing slab for a shed?

[landyvlad]

I have a slab which mates up with the inside corner of a fence.  The slab is not flat and falls toward this inside corner - so water collects there a lot.  In that corner the level is probably around 2" lower than the other corner of the slab which is about 5x2 metres.

I have a DIY kit garden shed build to do, and need that area flat first as I don't want water accumulating there and finding its way into the shed. 

So far I bought some yellow levelling compound from Bunnings (I cant recall what specifically) and that worked really well and has held up, but there was nowhere near enough of it. 

When I went back I couldn't recall what it was so I just grabbed another filler product - which I didn;tr realise at the time but do now - was not designed for outdoor use because it has all cracked and flaked.  Expensive lesson.

So what is my best option?

Can anyone name the specific product I should look for at Bunnings?

Alternatively should I just fill with standard cement? Or concrete?

I would like the EASIEST solution please because I want to get this done in the short term.

Ta. 

[EricL]

Hello @landyvlad

Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your question about floor levelling.

I suggest removing the cracked and flaking leveller that you used earlier. Once the area is clean, I suggest using Lanko 20kg 173 Floor Leveller. It's made for both internal and external use. It can be applied from 1mm up to 25mm thickness. I suggest installing timber formworks to prevent the leveller from flowing out of the area.     

Please keep us updated with your progress, we look forward to seeing your floor level and ready for use.

If you need further assistance, please let us know.

Eric