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Posted: Fri Nov 26, 2004 11:01 pm
by MickH
Fantastic web site.
I was wondering if anyone could tell me if British Standards covered things like:
- 100mm Sub Base + 50mm sand?
- Use of DTp1?
- Use of sharp sand not building sand?
- Concreting in of the edgings?
Is it possible to get B Standards on line?
Thanks in advance
Mick
Posted: Sat Nov 27, 2004 11:13 am
by steve r
Posted: Sat Nov 27, 2004 3:33 pm
by MickH
Thanks Steve,
Reason I was asking is that the contractors doing my drive don't seem to have done some of the essentials Tony lists in his wen guides - wish I'd come across this web site earlier - I'd have asked the right questions.
In particular:
They seem to have put in a very thin sub base - 50mm thick for the most part - we have a clay soil.
Sub base material looks like chopped up builder's rubble so I'm guessing it's not DTp1.
The sand layer was quite thick but feels soft - more like building sand than sharp sand.
And the edging blocks are set in the sand with concrete at the edge only, rather set into concrete.
Now they didn't explicitly say that would do any of this to the standard recommended in Tony's web site but they did say they work to British Standards - BS 6717 being the most relevant one I assume.
Question I have is are things like 100mm Sub Bases, bedding in edging etc stipulated / recommended by British Standards? If they are then they haven't done the work to British Standards. If they aren't then I've learned a lesson for next time.
Mick
PS I was hoping somebody might know the answer and save me buying and reading the British Standards until I know it's helpful.
Posted: Sun Nov 28, 2004 9:52 am
by MickH
Ok
Read through the main web site - has Tony ever written a book? The web site is a incredible resource.
Found a reference BS7533 and:
- Edge courses.
- Depth of the bedding layer.
- Cut blocks (they've done this well by breaking the pattern to avoid darts & slips - and as the FAQ says - you don't see it unless you're looking for it).
But can't find anything about the depth & composition of the sub base.
Mick
Posted: Tue Nov 30, 2004 6:49 pm
by steve r
Tony is probably slaving over his keyboard right now, constructing his book.
Try this page http://www.pavingexpert.com/faq_subbase.htm
All the answers to your questions are on there, try navigating from this page http://www.pavingexpert.com/pavguide.htm
Posted: Wed Dec 01, 2004 9:38 pm
by Tony McC
Tony's book is "getting there", very slowly, and far too slowly for my publisher's liking, but it should be in the shops (the charity shops and discounted book stores, that is!) by this time next year.
In the meantime, you;ll have to make do with me "in the flesh".
From what you've told us, these <s>cowb..</s> contractors wouldn't know what was in BS 7533:3 if it jumped up and bit them on the arse! As with lots of other British Standards, 7533 cross refernces other "Approved Documents", so items such as sub-base are covered in the Specification for Highway Works (SHW) and drainage is covered in Document H or Sewers for Adoption 5th ed. It's a great way of boosting sales of what are, when all's said an done, bloody boring documents!
100mm of sub-base is the generally accepted minimum thickness for a sub-base. The actual thickness is supposed to be calculated by determining a value referred to as the CBR of the sub-grade, and then factoring for traffic loads, after allowing for design life and multiplying by the colour of your socks. For the vast majority of residential driveways in Britain and Ireland, the result is usually 100-150mm of sub-base.
As for composition, DTp1 is the best. You can use lesser materials, but it's a silly corner to cut, and it doesn't save that much. The price diff between using DTp1 and summat like 50mm crusher run owld concrete on a typical drive of 50 square metres can be as much as 200 quid. I'd rather spend the 200 quid and know the job's been done properly than let Mrs Taz fritter it away on a new hairdo or a new frock while I worry that my drive will sink any minute now!
Incidentally - BS6717 covers the manufacture of Block Pavers, not the installation. It's even more boring than 7533!
Posted: Thu Dec 02, 2004 8:02 pm
by MickH
Tony, my "contractors" give cowboys a bad name. My brain must've taken the day off without telling me when I let that bunch of tw@ts on my drive. You live & learn.
Reached a financial settlement with them (lots of shouting needless to say) and I'll fix the edging so it stays where it is. Don't suppose any problems with the sub base will show up for a while.
Very difficult to know what you are getting without some of the background info you give in your web site. Doubt if I'd recognise DTp1 if it fell on me head. But at least I now know some of the things to look out for.
Is a shame firms like this seem to dominate the residential drive market round here. Most of the firms seem to be related as well - all brothers, cousins, sons etc. They must undercut the better firms and how does the average punter know that they aren't being quoted for a good job?
As you say, for a few quid more the cowboys could do it properly, but it's not difficult for them to quote low and then shortcut their way to a profit.
Next project is a patio and path in the back garden. Think I'll do this one myself. Will post pictures (if I don't boll0x it up).
