Page 1 of 1
Posted: Wed Apr 15, 2009 5:27 pm
by Stephen H
Hi all. I've purchased a couple of thousand square (150 x 150 mm) pavesetts from Pavestone. They don't have the wee tab to acheive a regular spacing (like my grey edging course does). The supplier told me to just butt them together but surely this won't achieve a good look or join over changes in grade - especilly over the fast changes at the pavement end of the driveway. I'm doing a stretcher bond (I know that heringbone would have been better for a driveway but my sister liked the square blocks). Should I put in a 2 - 3 mm gap between blocks and how would I best go about keeping a regular spacing? There is a bit of bevel on the edges (they have been tumbled a bit I think) but not as much bevel as standard 100 x 200 tabbed blocks. Should I put in the jointing sand before or after compaction with the wacker plate? Many thanks in advance for any replies.... Steve
Posted: Wed Apr 15, 2009 8:09 pm
by lutonlagerlout
Posted: Fri Apr 17, 2009 8:55 am
by Tony McC
If laid flexibly, then they should be laid relatively loose to allow jointing sand to get in between the elements and provide the vertical interlock necessary to give the pavement real strength. This advice to 'butt-joint' them is BAD advice, and to be fair, Pavestone are not the only ones coming out with this nonsense. Because they are importers/retailers rather than actual pavement construction specialists, they like everything to be easy-peasy even if it's less than accurate.
I know some contractors use tile spacers or slivers of plastic from ice-cream tubs, but with a bit of practice, it's not too difficult to lay them loose enough to allow them to be properly jointed.
However, as a DIYer, the tile spacer option is probably the easiest.
Posted: Fri Apr 17, 2009 1:49 pm
by Stephen H
Thanks very much for the advice. After all the effort I've gone to to get things right, I don't want to bodge up the final part. Can I just leave the tile spacers in (at the bottom corners of the blocks I guess), add jointing sand and wacker? I'm thinking it would be best to put them at the top, add kiln sand to joints and then remove them all before final compaction - but i can also see that being a fiddle and having spacers fall in and all that faf.
Incidentally, I've ended up with a bit more than 5 cm for the sharp sand bedding layer (6 to 7 cm). Is this too much for 50 mm blocks? Should I remove the sand and put a bit more aggregate so that I only have 35 - 50 mm after compaction?
Cheers - Steve
Posted: Fri Apr 17, 2009 6:16 pm
by lutonlagerlout
yes m8
70mm of bedding sand will sink faster than a Somali skiff full of ransom money
do it right 
LLL
Posted: Sat Apr 18, 2009 11:33 am
by Tony McC
In practice, when tile spacers are used, they tend to be left in situ as they are not worth rounding-up and they are so small they really have a minimal effect on the vertical interlock.
There is a Dutch (might be Belgian) system that uses pricey placky spacers which sit on top of the paving with a 'prong' that protrudes down between the paving elements and creates an accurate 3mm joint (6,10 and 12mm versions are also used). These are collected up at the end of the job and re-used on the next job, but it all seems a little bit OTT to me.
Posted: Mon Apr 20, 2009 9:16 am
by Stephen H
Thanks very much for the advice guys. I bought some regular 3 mm tile spacers for a few quid so I'll go with that method I think.
I will also add a bit more aggregate so I will have 35 - 50 mm sand (after compaction of course).
cheers - steve
Posted: Wed Jul 22, 2009 10:02 pm
by Thrive Landscapes
Hi there,
We laid a fairly large drive (100sqm-ish) in February 2006 using the forementioned nibless pavestone blocks and we've had nothing but trouble. Having laid them stretcher and butt jointed (As instructed by Pavestone) the blocks have moved. This movement is manifest as a "Ripple" effect, with the blocks being knocked out of line where the car wheels run across them, giving a ripple effect as you look down the lines. The client is understandably unhappy (and he's not the only one) so I can't see any option but to relay it all. I guess from previous comments using spacers would be a good idea, but do I have any chance of claiming any costs from Pavestone for the work? We've had a site visit from a Rep already and he was very elusive, trying to blame the movement on the sub base (as the blocks have started to wriggle down into the bedding layer causing slight wheel ruts) and a large (but particularly invasive) conifer planted beside the drive, but I'm not convinced by either of those. If it helps I can email you some pictures, if you need a laugh!
Thanks for your help,
Steve (going slowly crazy!)
Posted: Thu Jul 23, 2009 11:34 am
by David Sarti
Steve - I've removed my comment. I was primarily intending to inform; not specifically give offence to JL and his colleagues. I cannot avoid decontextualised third-party comment and others' personal agendas surfacing on the rare occasions I express a personal opinion, so better to say nothing in hindsight.
Jon L - my apologies; my comment was inappropriate and I withdraw it unreservedly. I'm sure the 'nibs' vs 'no nibs' debate will now run and run.
Edited By David Sarti on 1248690994
Posted: Thu Jul 23, 2009 7:46 pm
by Thrive Landscapes
Hey David,
Thanks for that, at least I know why they do it now, but I now feel I've been stitched up cos they weren't cheap by any means! I can't remember prices exactly, as it was several years ago, but they were certainly the top end of the price scale, I've got around £18m2 in my head, and the suppliers we bought the blocks from soon after changed to a different manufacturer as the Pavestone blocks were too expensive!
Lets just say I won't be using Pavestone again!
Steve
Posted: Sat Jul 25, 2009 2:59 pm
by Jon Layton
Steve
Having just picked up on your tread I would like to clarify and correct some of the mis-information given to you to date. I too have to declare a vested interest as I am a director share holder in Pavestone.
Firstly, there is infinitely more block paving laid in the world without nibs than with nibs. However the UK does predominantly produce block paving with nibs which most would argue are there for cosmetic reasons only. Next time you visit mainland Europe or the USA take a look at the huge spectacular areas laid with nibless block paving.
In the UK we have sold millions of metres, much to our competitors annoyance, of nibless blocks over the years and have established quite a loyal number of landscapers who prefer to lay nibless blocks, citing less weeding maintenance for the end user.
Mr Sarti generalises when he states that Pavestone blocks are made on edge. It is true we have one range of blocks that is made on edge; however the majority of the blocks we sell are pressed flat, as are his products. So without details of which product you have purchased, it would be wrong, misleading and slightly mischievous to speculate which type of blocks you have and to proffer disparaging comments.
I'm afraid the experience you have had with blocks moving is down to the installation. If the sub-base is fully compacted, on good firm ground and the block paving is fixed around the perimeter of the area then the blocks will not be able to move.
Unfortunately I am on holiday for two weeks now and not able to discuss this with you, however Kevin Fowler (Managing Director) would be happy to discus your specific problems should you care to ring our office on 01386 848 650.
Incidentally the blocks are manufactured for us by one of the largest building materials manufactures (CRH) in the world.
http://www.landscapejuice.com/2009....ne.html
Posted: Sun Jul 26, 2009 9:01 am
by lutonlagerlout
infinitely , thats a a very vague term, I have been laying CBP for 22 years and i have only seen nibless blocks once.
i cannot understand why the nibs are cosmetic,surely they function to maintain an even spacing?
while we are on nibs ,could you tell me david why drive sett duo is marketed as having 2 colours which can be laid either way up to achieve a multicoloured look
but when you do this in practise,the nibs clash and cause the blocks to rack out of true?
maybe the nibs should have been smaller to allow for this?
and steve, it sounds like your subbase or edge restraint has failed.
LLL
Posted: Sun Jul 26, 2009 12:48 pm
by Thrive Landscapes
Thanks for the reply LLL.
The edges are still solid and despite some minor wheel rutting the sub base seems fine too, the only question I really need answering is do i relay them with spacers or trust the magic nibless blocks to behave themelves?
Many thanks to Mr Layton for his comments, and I thank him for condemning my workmanship from the comfort of his office. And while he may be enjoying a nice fortnights holiday I regret to inform him I will be unable to view his companies marvellous products in Mainland Europe or the USA, with the trouble his products have caused me I won't even be able to manage a weekend in Grimsby (no offence intended to any residents of Grimsby, I've heard many good things about it.)
Although only in the trade for a meagre 10 years this is also my only encounter with nibless blocks, but as they have sold millions and have a loyal fan base I guess it doesn't matter that I'm going elsewhere.
Posted: Sun Jul 26, 2009 2:57 pm
by Tony McC
Nibless pavers *are* used in Europe but I'm not sure they are in the majority. In fact, I'm not sure that they would have more than 30% of the market, but it all depends on what you define as the European market.
I've heard endless arguments both for and against nibless blocks, and I'm firmly of the opinion that nibless blocks are better for the manufacturer while nibbed pavers are better for the contractor and the customer. Setting aside all the pros and cons of having sand-filled joints, the killer argument for me is the incidence of spalling. You get much less spalling with a nibbed block.
We do things differently in Britain and Ireland. We don't use shaped blocks anywhere near as much as our continental cousins, and, to be brutally honest, nowhere near as much as we should do, and we like nibbed blocks that generate a regular joint. In fact, the British Standard requires a joint of 2-5mm, so if nibless blocks are laid butt-jointed (as opposed to close jointed) they don't comply with the BS.
I'm sure Jon and others that import/distribute/manufacture nibless blocks will argue that the BS doesn't necessarily apply to driveways or patios, and that the BS is a recommendation, not a ruling, but the fact remains that, by and large, the BS represents the latest thinking on Best Practice and it's damned hard to make an argument to counter that.
Personally, I'd be more guided by the appearance and reliability of the block rather than whether it had spacer nibs or not. When the jobs done, the client is most concerned about colour, texture, and accuracy rather than whether there are nibs on the blocks. I'd always lay nibless blocks relatively loose with the intention of getting some jo0inting material between the units, but I wouldn't ever refuse to lay nibless.
Posted: Mon Jul 27, 2009 9:36 am
by David Sarti
Tony (LLL) - good question re: Duo. I'll get someone onto that straight away.