The Brew Cabin

Posted: **Thu Feb 15, 2007 10:20 pm**

Hi,

Having reduced level to a heavy gravel soil base for my 10m2 patio project I need a bedding layer of roughly 50-60mm. I note from your website that it is possible to use ballast/cement 10:1 rather than a course grit sand mix for bedding indian sandstone.

Having spoken with Wickes, the ballast they stock can contain aggregate upto 25mm in size.

Is this ok to use as a bedding layer or should I try and get a finer ballast? I would like to use ballast if possible because it is cheaper and only one bulk bag to deal with.

Your help is appreciated as I would like to crack on this weekend.

Cheers

JIm.

Posted: **Fri Feb 16, 2007 12:05 am**

You should be ok.

The generally accepted rule-of-thumb is that the aggregate must be no more than half the depth of the layer in which it is used.

This is explained more fully here

Posted: **Fri Feb 16, 2007 7:29 am**

Perfect, thanks Tony.

Posted: **Fri Feb 16, 2007 10:20 pm**

i dont wish to pee on your bonfire ,but i would never use ballast as the bedding layer when it is only 50-60mm thick
surely grit/flooring/screeding/river wash/hartican sand will do this job better mixed 10:1
with ballast i always aim for 100mm minimun,i think tony is referring to the subbase===> i could be wrong??
regards LLL ???

Posted: **Sat Feb 17, 2007 10:13 am**

No, you can use the sandy "All-in Ballast" as a laying course, but I do actually prefer a grit sand. The problem is that, particularly in the aggregate poor sarf-eest of Engerlund, good quality sand is hard to come by and many of the big DIY sheds only supply an all-in ballast.

I'm not a fan of it being used unbound (ie: no cement) but it's not too bad when beefed up with 10-20% cement and used for patios.

Posted: **Sat Feb 17, 2007 5:34 pm**

when we were allowed to do crossovers,we had to use leanmix with a 20mm aggregate,unless we had 100mm bedding course you could almost guarentee there would be a rogue stone 20mm thick but 50 long that would cause rockers
i have got 20 mm shingle on my drive ,yet i think this is just what passes though a 20mm shaker/sieve,some bits are 40mm by 20mm and some go down the 10 mm grate on the linear drain
i agree on the poor quality aggregate down here, though
cheers LLL

The Brew Cabin

Ballast as bedding for sandstone - Ballast aggregate size