John's Alu Profile build

[Evengravy]

You might be better off trying self leveling floor compound, it runs like water.
Regards
Mike

Thanks Mike, I'm kind of committed to this way of approaching it now as I have all the bits and bobs ordered. The resin I have is really low viscosity so it's really just a case of roughly evening the concrete surface before hand, shouldn't be a massive chore but without doing so the majority of the resin would sit in the centre leaving an overly thin layer at the sides where the rails will sit. It's not far off as it is though, about 5mm in the worst spots so it'll be fine with some gentle massaging. Appreciate the point though, I might source some of that to level any low spots on the floor of the space itself before painting it.