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Posted: Fri Sep 10, 2010 10:26 pm
by Blocker
Ok, I'm about to order the sand for screeding, to cover 60m2, to be 40mm thick after screeding, that's 5mm thicker to make the blocks 5mm proud.
How deep should it be before compaction?
The calculator on the website asks what is the compacted size? Is that before or after screeding, so to estimate the amount of sand I need?
How many mm's is normal to screed off?
Any tips?
Regards.
Posted: Sat Sep 11, 2010 12:55 am
by lutonlagerlout
you need 5-6 tonnes
LLL
Posted: Sat Sep 11, 2010 6:49 am
by mickg
>>>>How many mm's is normal to screed off?
10 - 15mm
if you try to do less than this you will end up with low spots somewhere on your driveway
>>>>>How deep should it be before compaction?
fix a tight line to steel road pins to the finished height of your paving, don't forget you need to allow for fall to disperse any surface water
get a paving block for your depth and allow 30mm above this line, this will give you approx 15mm for compaction and 15mm to screed off
if your hardcore is not perfectly flat then the sand laying coarse will compact slightly more in these low spots so likewise work to a tight line to get the hardcore sub base as flat as you can and as compacted as much as you possibly can, you will know when it will not compact any further as the wacker starts to bounce - thats when you can stop compacting
block paving is all about preparation 
Posted: Sat Sep 11, 2010 8:22 am
by lutonlagerlout
^^ listen to mickg ,he KNOWS blockpaving
LLL
Posted: Sat Sep 11, 2010 8:31 pm
by Blocker
Thank's for the advice Chaps.
I've completed the block work outside course all the way around obviously going to fill the sand inside this.
I have 65mm block's sitting on 35mm muck giving me 100mm deep hole to fill.
Finished compacted screed to be 40mm deep, so I should fill up to 30mm from top of the blocks 70mm deep, compact it down 15mm then screed off 15mm leaving the 40mm to lay blocks on.
6 tonne of sand for this then?
Sound about right? Am I getting it?
Wow what a head do'er!
Posted: Sat Sep 11, 2010 9:54 pm
by mickg
who manufacturers a 65mm deep block ?
>>>>so I should fill up to 30mm from top of the blocks 70mm deep, compact it down 15mm then screed off 15mm leaving the 40mm to lay blocks on.
yes
>>>>6 tonne of sand for this then?
it will take between 5 and 6 ton approx, you only need to be 10mm out in a few area's on the depth of your sub base and you will require more sand for the laying course so the amount of sand is all down to how flat you have prepared your hard core sub base
Posted: Sun Sep 12, 2010 7:08 am
by Mikey_C
Blockleys' chamfered clay paviors are 65mm thick
Posted: Sun Sep 12, 2010 7:36 am
by lutonlagerlout
its a very unusual size mikey
most CBP is 50 or 60mm now
well found though
LLL
Posted: Sun Sep 12, 2010 7:47 pm
by Blocker
Definitely 65mm, don't know the make as I got them off eBay second hand.
Again many thanks for the advice, I'll be back in touch again very soon I'm sure! 
Posted: Thu Apr 14, 2011 6:56 pm
by Blocker
At last, sharp sand ordered! Starting the job again on Monday.