The Brew Cabin

I have extensively used pavingexpert.com for my latest project - a new driveway. First let me congratulate those behind the site, you must have put many hundreds of hours into it just to help people like me.

Now onto my query.

I am laying 450x450 saxon flags (50mm) on the drive. I have rigidly followed your advice and used a 100mm MOT sub-base and a 50mm 10:1 sharp sand to cement bedding layer constructed using the precompacted method. However, today, when I laid the flags onto this bedding layer I was surprised to find there was no 'give' and the flags sit on the surface even after a few hits with the rubber mallet. This results in some mild rocking in a few cases.

What did I do wrong? I am laying the remainder tomorrow and would like to get it right.

Thanks

If there's no 'give' at all, that suggests the laying course is already compacted to refusal.

Try running a rake through the screeded bedding, just so that it 'loosens' it without re-distributing the sane/cement everywhere. Then place your flags and you should find a few taps with the maul settles them down nicely.

Are you using a maul, or is this one of the little rubber clonkers? There's not really enough wallop in the rubber clonkers for bedding 50mm thick driveway flags - you really do need a maul.

Tony
thanks for the fast reply.

I think you hit it on the head (apologies for the sort of pun!!). I am using a rubber hammer. I'll try to hire a proper maul in the morning and I'll do the raking suggestion.

Once again, great work !!

I finished the drive and it does look damned good. Not only that but the flags are solid as anything. Thanks for all the advice.

I now have the bit between my teeth and I intend to rip up the tarmac drive in front of my garage and replace with the same flags as the new drive mentioned earlier.

I cannot hire a decent maul anywhere, so before I start the job in two weeks, should I do something different to before, perhaps not using a whacker to pre-compact the 10:1 mix screed, or stick to raking off the surface like last time?

Steve

You can buy a maul for around 25 quid (www.greenham.com) which makes hiring one seem silly.

As for the prep, on a driveway it's better to lay the flags on a full bed of concrete, minimum 100mm thick, rather than a sub-base and 35-50mm bedding layer. However, it's most probable that the're a damn good sub-base nbeneath your existing bitmac and it seems silly to get rid of that. Is there any chance of over-laying the existing sub-base with 75-100mm of concrete plus the flags?

If not, your options are to use a stronger bedding mix, say 6:1, or to dig out some of that sub-base and use the 100mm concrete bed.