Grano dust

[TheFlute]

A friend has said he can get me some Granodust at the right price. Is it okay for screeding my block paving? Any advantages and disadvantages.
Also I've got a couple of low spots (about 10mm) is it better to hardcore those areas or will the screed take up that much.
Thanks Phil

[Lmcd qs]

Hi Phil,

I would personally avoid the granodust only because I have never saw it used and I tend to stick with what I know. I also don’t think you will be at much of a saving when you compare the price to sand.

If your paving is already laid you can find useful info to help you with your low spots at https://www.pavingexpert.com/repair

If not, and you are at sub-base level and ready to lay your bedding, then I would recommend you raise the low spots using the same material as the rest of your sub base.

You want to lay your paving an evenly compacted sub base and bedding and if you fill the low spots with inadequate material then these areas will be more likely to settle in the future.

There is a great amount of guidance which will help you over at https://www.pavingexpert.com/block-paving

[Tony McC]

Traditional grano is closer to a self-binding gravel than it is to a sand as it tends to....well, bind, become claggy and form a hard-ish, almost impermeable surface, so it's not really a good choice for a laying course.

However, some of the stuff now sold as 'Grano' is actually just a crushed unspecified rock (rather than a specific limestone from North Lancashire and parts of N. Yorks) and this *does* seem to be better suited to use as a laying course material.

You need to determine which material is up for offer....but to be honest, I'd stick with a proven grit sand.

[TheFlute]

Thanks both for the reply. I'll stick with the sand. Saving would have been about £150 but not worth the risk.