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Posted: Thu Jan 01, 2015 3:09 pm
by sy76uk
I know what your saying Tony but the 3.5 ton load bearing should only apply to the blocks themselves so I'd expect to see broken blocks farther than the amount of subsidance you can see in the pictures. I doubt there's 150mm of sub base in there.
Posted: Thu Jan 01, 2015 6:29 pm
by msh paving
who say 3.5t for a domestic driveway? with the right subbase bockpaving will take a 10t load no problem MSH 
Posted: Thu Jan 01, 2015 7:16 pm
by lemoncurd1702
msh paving wrote:who say 3.5t for a domestic driveway? with the right subbase bockpaving will take a 10t load no problem MSH
Totally agree.
I've had 10T loads plus the lorries weight of about 6T dropped on my work with no problems. And that's 50mm blocks, they do not crack under weight but more likely from lateral pressure.
A driveways makeup is designed for domestic use but it should withstand occasional use by a commercial vehicle if constructed as MSH states.
Posted: Thu Jan 01, 2015 10:01 pm
by sy76uk
The load bearing for 50 or 60mm blocks is 3.5 tons according to most manufacturers, anything over that you should use 80's.
As some of you will know my background is in commercial paving and I've had just about any heavy vehicle you can imagine drive over my work so I have a lot of experience with this subject.
The worst thing that can go over block paving are the big solid wheeled cherry pickers.
Unlike msh and lemon curd I have seen 50mm blocks break under heavy loads although they were probably rubbish blocks to begin with.
IMHO, there's something not right for a lorry doing that much damage on one run.
Posted: Thu Jan 01, 2015 11:21 pm
by lutonlagerlout
you are still not listening guys
most manufacturers still only rate drives with 50mm blocks to 3.5 tonne
apocryphal tales of drives taking 10 t are all over the gaffe
but if you want to guarantee it you must use 70- 80mm blocks and a bigger sub base
I know that IMHO 50 mm blocks are no good for any sort of 7.5t + vehicle
some will hold it/some wont
LLL
Posted: Fri Jan 02, 2015 12:23 am
by lemoncurd1702
The problem that arises with the thinner blocks is rotation and hence the possibility of the pavement buckling.
Can't see how the contact area of a tyre could crack the block especially if you think about the punishment they take from the wacker. It's difficult enough to crack a block with a chisel when held in place by the surrounding paving.
If there's any cracked blocks in that drive it probably happened during installation either due to a flawed block or more likely where the 90' herringbone has gone askew forming a point which puts pressure on the adjacent block during compaction. Notice how they always split in the centre where the corners of the adjacent blocks meet.
Posted: Fri Jan 02, 2015 10:27 am
by nishan8178
Hi LLL,
Yes we do live on a tight road but the lorry backed up in order to tip as they did not have a crane (so they had to open up the back compartment). The topsoil company website quite clearly says that their vehicle comes armed with crane, qualified staff and what not. So I instructed to tip from the roadside on my invoice and followed this up from a phonecall day prior to delivery.
The delivery company are not being helpful at all; they are trying to say we invited them onto the driveway where evidence is clearly to the contrary.
Wish you all a happy new year!
Regs
Posted: Fri Jan 02, 2015 12:17 pm
by GB_Groundworks
fyi using the likes of everest etc for paving
they charge you £10k and sub it to a local guy for £5k and then force the local guy to go over and above as the suited salesman from everest has promised the world but the local guy has quoted just for the drive been a few posts about them in the past on here
Posted: Fri Jan 02, 2015 12:45 pm
by lutonlagerlout
IME topsoil is nearly always delivered loose unless you pay a kings ransom to have it in bags
normally around £20 /tonne loose as opposed to £40 in bags
LLL
Posted: Fri Jan 02, 2015 7:02 pm
by sy76uk
I know exactly what you mean lC. All I can say is that I have seen cases where blocks have been broken quite badly by heavy machines on a few occasions. I've even seen 80's permeable blocks rutted and broken due to cherry pickers driving all over them.
I had a big lorry drive over the edging course on a drive that I'm working on today so I thought I'd take a picture while he was on it. He had a 7.5 ton load of millwaste on and the edgings didn't budge. Photo's are on my FACEBOOK page. https://m.facebook.com/Sampaving?ref=bookmark
Posted: Fri Jan 02, 2015 8:55 pm
by mickg
I can only see two blocks what look like they have cracked highlighted by the dampness ?
all the signs are visible in photo of the driveway not having the correct depth of sub base which is why the weight of the wagon has made the blocks sink and also heave due to soft ground, like already mentioned 100 - 150mm depth sub base with a 50mm paving block is only suitable for light weight vehicles, a 7.5 t box van delivering parcels could do the same amount of damage
we always lay a semi dry concrete sub base if the home owner has a SUV which can weigh about 3 ton empty or if the home owner has a medium size van being parked on the same track every day we stabilise the ground with concrete before continuing to the next stage
Posted: Fri Jan 02, 2015 9:45 pm
by sy76uk
I've been thinking of swapping from millwaste to lean mix on all my drives Mick. Having said that I always dig off off at least 250mm, most of the time it's more like 300-350. I always put the edge restraints in and lay terram before any mot touches the ground, that gets compacted in 100mm layers and I never have more than a 30mm bed of sand down.
All that to me should be enough to prevent subsidence on a domestic driveway even with the occasional heavy vehicle (removal lorry, bin lorry ect) without issue.
You can't beat concrete a sub base though. It's the only way of knowing for sure that the blocks aren't going anywhere.
Posted: Fri Jan 02, 2015 10:03 pm
by Kuts
ive had these boys on the phone trying to get me to use this stuff instead of dtp1
http://www.monebros.co.uk/smr.html
what do you guys think? ive never tried it, its about £12t so same as type1 limestone
Posted: Fri Jan 02, 2015 11:33 pm
by lutonlagerlout
I know a lean mix subbase goes against everything that should happen in flexible driveways
but the bets drive layer in luton tom togher (now retired) always used leanmix and i see drives he did 25 years ago on a regular basis and they are still 100%
also personally I just dont like 50mm blocks
IMHO
LLL
Posted: Sat Jan 03, 2015 8:36 am
by lemoncurd1702
Kuts wrote:ive had these boys on the phone trying to get me to use this stuff instead of dtp1
http://www.monebros.co.uk/smr.html
what do you guys think? ive never tried it, its about £12t so same as type1 limestone
Why not give it a try on a patio base that isn't to be subjected to the same load as a driveway.
I use a recycled grit sand which is made of ground up waste and washed to remove soil particles.
If anything it's better than the dredged stuff which is no longer available here.