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• 

  Iain Truman November 2, 2010 at 6:20pm

  Hi William,
  
  I could answer all of those questions after picking up a few documents for various bits and pieces of information, and I think that is the key to answering your main question. There is currently no 'one stop' definitive guide to sustainable block paving, certainly one that explains things in plain English, practical terms. I think it's a great idea, and something very useful for an ever changing industry. We certainly need something to remove the mystery from this type of application, making it feasible for all contractors and not just the specialist, and ultimately making this more environmentally considerate application accessible to more clients rather than just those with the biggest budgets.
  
  Good luck with it all
  Iain Truman
• PRO

  Will - WB Design & Construction November 2, 2010 at 11:07pm

  I agree there are many ways to skin a cat when it comes to sustainable drainage, however for the purpose of the dissertation I have had to narrow it down a bit and this is the route I propose partly because of many peoples reluctance to use sustainably drained block paving due I belive partly to the fact that people do not know all of the facts.
  
  Just a question when intalling other types of sustainable drainage doloutions, do you calculate storage capacities to check that they are capable of holding a 10 year event, to comply with the approved document H?
  
  Gary @ Acer Paving & Landscaping said:

  It would be interesting to see how many LJN members who do block paving use "permeable block paving" regularly or at all.
  
  For my part, we don't and probably have no intention of doing so.
  
  That's not to say our methods don't comply with current reg's and it's my impression that the majority of contractors have this approach - I could be wrong !
• PRO

  Will - WB Design & Construction November 2, 2010 at 11:11pm

  My thoughts exactly yes the information is out there but you have to search around to find it and it often takes a good understanding of science and maths to work out exactly what it is you are reading.
  
  
  Iain Truman said:

  Hi William,
  
  I could answer all of those questions after picking up a few documents for various bits and pieces of information, and I think that is the key to answering your main question. There is currently no 'one stop' definitive guide to sustainable block paving, certainly one that explains things in plain English, practical terms. I think it's a great idea, and something very useful for an ever changing industry. We certainly need something to remove the mystery from this type of application, making it feasible for all contractors and not just the specialist, and ultimately making this more environmentally considerate application accessible to more clients rather than just those with the biggest budgets.
  
  Good luck with it all
  Iain Truman
• PRO

  Will - WB Design & Construction November 3, 2010 at 8:35am

  Hi stuart, some nice work om your web site. Yes to an extent you are correct it will block up but most systems are designed to be 95% blocked and still allow all the water to flow through to the sub base. As long as they have been corectly maintained, and installed they should provide at least 20years of service pefore any work is required.
  
  As for why only block paving, well I would love to cover a vast array of subject but with just 10,000 words it just isn't possible.
  
  As for resin bound I really like the effect and the idea however I think it would be suseptible to the same problems of pores blocking up, please correct me if it is wrong. Also Aquapaves website shows the construction using type 1 aggregate and therefore there would be a very small water storage capacity and also a slow infilltraction rate through the compacted type 1 or am I missing something here, surely the sub base needs to be constructed from type 3 to provide sufficent water storage, if this is not the case I would be very interested to know how it complies with the regs.
  
  Cheers Will
  
  In an ideal
  
  Stuart Marler said:

  Its a shame that this thread is only about block paving as there are so many better alternatives to sustainability surfaces.
  
  I would not use this type pf block paving, as the gaps between the blocks are too large and will silt up in a short time, thus reducing the porosity of the product. It will depend on each area as to what speed the porosity will be affected.
  Yes the product can be jet washed but then the process will remove the aggregate and will be costly to reinstate but this will not completely clear the silt only a certain percentage.
  
  Amongst other alternatives are:
  http://www.aquapave.co.uk/
  Resin Bound Aggregate
  CoreGravel - and similar
  
  Stuart
  TVG Landscaping
• 

  Iain Truman November 3, 2010 at 9:47am

  Will,
  
  I was about to raise the very same points that you have, I think any porous surface is only going to be as good as its aftercare. All surfaces porous or not will be susceptible to silting, and my experience of porous resined surfaces, bound or bonded is exactly that. I would suggest also that any form of water filtration, storage or drainage system that uses type 1 or any sub-base with finings will always silt up, therefore a clean aggregate sub-base is essential, like type 3, but getting hold of it is the hard part.
  
  I would agree that aesthetically the wide gaps of the permeable block paving systems are an issue, and do not look as good as a standard or Tegula block paved surface, but in these times we have to make compromises somewhere. That has to be either the aesthetics of permeable blocks or the expense of aqua cells or other systems and channel drains, something else that is not exactly aesthetically pleasing either.
  
  A good thread though, and some interesting views so far, it would be nice to hear the other side of the story though, if anyone would naturally favour the installation of permeable blockwork? It would also be interesting to see how other people are complying with the regs in other ways.
  
  Iain
  
  
  
  Will - WB Design & Construction said:

  Hi stuart, some nice work om your web site. Yes to an extent you are correct it will block up but most systems are designed to be 95% blocked and still allow all the water to flow through to the sub base. As long as they have been corectly maintained, and installed they should provide at least 20years of service pefore any work is required.
  
  As for why only block paving, well I would love to cover a vast array of subject but with just 10,000 words it just isn't possible.
  
  As for resin bound I really like the effect and the idea however I think it would be suseptible to the same problems of pores blocking up, please correct me if it is wrong. Also Aquapaves website shows the construction using type 1 aggregate and therefore there would be a very small water storage capacity and also a slow infilltraction rate through the compacted type 1 or am I missing something here, surely the sub base needs to be constructed from type 3 to provide sufficent water storage, if this is not the case I would be very interested to know how it complies with the regs.
  
  Cheers Will
  
  In an ideal
  
  Stuart Marler said:

  Its a shame that this thread is only about block paving as there are so many better alternatives to sustainability surfaces.
  
  I would not use this type pf block paving, as the gaps between the blocks are too large and will silt up in a short time, thus reducing the porosity of the product. It will depend on each area as to what speed the porosity will be affected.
  Yes the product can be jet washed but then the process will remove the aggregate and will be costly to reinstate but this will not completely clear the silt only a certain percentage.
  
  Amongst other alternatives are:
  http://www.aquapave.co.uk/
  Resin Bound Aggregate
  CoreGravel - and similar
  
  Stuart
  TVG Landscaping
• PRO

  Will - WB Design & Construction November 3, 2010 at 9:56am

  Indeed type 3 isn't as easy to get hold of as type 1 but is getting more available with many of the big names being able to supply it.
  Likewise it would be good to hear what other people are doing to satisfy the legislations.
  
  
  Iain Truman said:

  Will,
  
  I was about to raise the very same points that you have, I think any porous surface is only going to be as good as its aftercare. All surfaces porous or not will be susceptible to silting, and my experience of porous resined surfaces, bound or bonded is exactly that. I would suggest also that any form of water filtration, storage or drainage system that uses type 1 or any sub-base with finings will always silt up, therefore a clean aggregate sub-base is essential, like type 3, but getting hold of it is the hard part.
  
  I would agree that aesthetically the wide gaps of the permeable block paving systems are an issue, and do not look as good as a standard or Tegula block paved surface, but in these times we have to make compromises somewhere. That has to be either the aesthetics of permeable blocks or the expense of aqua cells or other systems and channel drains, something else that is not exactly aesthetically pleasing either.
  
  A good thread though, and some interesting views so far, it would be nice to hear the other side of the story though, if anyone would naturally favour the installation of permeable blockwork? It would also be interesting to see how other people are complying with the regs in other ways.
  
  Iain
  
  
  
  Will - WB Design & Construction said:

  Hi stuart, some nice work om your web site. Yes to an extent you are correct it will block up but most systems are designed to be 95% blocked and still allow all the water to flow through to the sub base. As long as they have been corectly maintained, and installed they should provide at least 20years of service pefore any work is required.
  
  As for why only block paving, well I would love to cover a vast array of subject but with just 10,000 words it just isn't possible.
  
  As for resin bound I really like the effect and the idea however I think it would be suseptible to the same problems of pores blocking up, please correct me if it is wrong. Also Aquapaves website shows the construction using type 1 aggregate and therefore there would be a very small water storage capacity and also a slow infilltraction rate through the compacted type 1 or am I missing something here, surely the sub base needs to be constructed from type 3 to provide sufficent water storage, if this is not the case I would be very interested to know how it complies with the regs.
  
  Cheers Will
  
  In an ideal
  
  Stuart Marler said:

  Its a shame that this thread is only about block paving as there are so many better alternatives to sustainability surfaces.
  
  I would not use this type pf block paving, as the gaps between the blocks are too large and will silt up in a short time, thus reducing the porosity of the product. It will depend on each area as to what speed the porosity will be affected.
  Yes the product can be jet washed but then the process will remove the aggregate and will be costly to reinstate but this will not completely clear the silt only a certain percentage.
  
  Amongst other alternatives are:
  http://www.aquapave.co.uk/
  Resin Bound Aggregate
  CoreGravel - and similar
  
  Stuart
  TVG Landscaping
• PRO

  Will - WB Design & Construction November 3, 2010 at 4:53pm

  Dear Stuart, thankyou very much for your reply, I am aware that this topic is very much a hot potato and that many contractors avoid talking about it, is part of the reason that people are reluctant to talk about it because of misunderstandings of the legislation and how these legislation can be met?
  
  I agree that permeable block paving is an expensive route to take for a domestic driveway and that there are other ways to skin of the perverbial cat. However there are some situations in which permeable block paving may be the only option.
  
  As for bonded aggregates I understand that they are supposed to be laid over a concrete or tarmac base, from my understanding this is constructed in a similar way to the methods used in heavy duty permeable block paving applications and whereby the tarmac concrete is a core drilled to allow water to soak into the storage medium below. I am unable to comment on whether this would work in the long term however this is recommended practice from Interpave for the construction of heavy duty permeable paving.
  
  I will would agree that the whole and this is why I have chosen to look into this as part of my dissertation and try to produce a document which clears up some of the confusion concerning permeable block paving.
  
  I hope neither of us end up regretting any of the comments we post on here as I feel talking and sharing knowledge is the only way to clear up the mess that is SUDS.
  
  
  Gary @ Acer Paving & Landscaping said:

  I think you are aware already Will, that this is a hot potato that not many contractors are willing to talk about, ( myself included ).
  
  I believe we do comply with curent reg's but I'm not going to enter into a public debate about it and have my methods picked apart.
  
  Permeable block paving is an expensive route to take in a domestic driveway and I think I'm right in saying most contractors prefer to find alternative materials and methods of construction that comply to the reg's without going down the permeable route.
  
  You're also right to pick up on the shortfalls of the bonded aggregate systems. I picked up on these issues in a thread a few months ago and frankly it just got people upset.
  
  Bonded aggregates are usually laid over an existing concrete or tarmac base or new tarmac base, none of which make it porous in any way. When I asked the supplier involved they admitted as much but added you have to drill holes in the tarmac to let it drain.
  
  Now, I think we all know what a complete waste of time that would be.
  
  Like I said, the whole thing's a mess and it's not in contractors interests to get drawn in to deeply.
  
  I'm sure I will soon regret posting even this response !
  
  
  
  Will - WB Design & Construction said:

  Indeed type 3 isn't as easy to get hold of as type 1 but is getting more available with many of the big names being able to supply it.
  Likewise it would be good to hear what other people are doing to satisfy the legislations.
  
  
  Iain Truman said:

  Will,
  
  I was about to raise the very same points that you have, I think any porous surface is only going to be as good as its aftercare. All surfaces porous or not will be susceptible to silting, and my experience of porous resined surfaces, bound or bonded is exactly that. I would suggest also that any form of water filtration, storage or drainage system that uses type 1 or any sub-base with finings will always silt up, therefore a clean aggregate sub-base is essential, like type 3, but getting hold of it is the hard part.
  
  I would agree that aesthetically the wide gaps of the permeable block paving systems are an issue, and do not look as good as a standard or Tegula block paved surface, but in these times we have to make compromises somewhere. That has to be either the aesthetics of permeable blocks or the expense of aqua cells or other systems and channel drains, something else that is not exactly aesthetically pleasing either.
  
  A good thread though, and some interesting views so far, it would be nice to hear the other side of the story though, if anyone would naturally favour the installation of permeable blockwork? It would also be interesting to see how other people are complying with the regs in other ways.
  
  Iain
  
  
  
  Will - WB Design & Construction said:

  Hi stuart, some nice work om your web site. Yes to an extent you are correct it will block up but most systems are designed to be 95% blocked and still allow all the water to flow through to the sub base. As long as they have been corectly maintained, and installed they should provide at least 20years of service pefore any work is required.
  
  As for why only block paving, well I would love to cover a vast array of subject but with just 10,000 words it just isn't possible.
  
  As for resin bound I really like the effect and the idea however I think it would be suseptible to the same problems of pores blocking up, please correct me if it is wrong. Also Aquapaves website shows the construction using type 1 aggregate and therefore there would be a very small water storage capacity and also a slow infilltraction rate through the compacted type 1 or am I missing something here, surely the sub base needs to be constructed from type 3 to provide sufficent water storage, if this is not the case I would be very interested to know how it complies with the regs.
  
  Cheers Will
  
  In an ideal
  
  Stuart Marler said:

  Its a shame that this thread is only about block paving as there are so many better alternatives to sustainability surfaces.
  
  I would not use this type pf block paving, as the gaps between the blocks are too large and will silt up in a short time, thus reducing the porosity of the product. It will depend on each area as to what speed the porosity will be affected.
  Yes the product can be jet washed but then the process will remove the aggregate and will be costly to reinstate but this will not completely clear the silt only a certain percentage.
  
  Amongst other alternatives are:
  http://www.aquapave.co.uk/
  Resin Bound Aggregate
  CoreGravel - and similar
  
  Stuart
  TVG Landscaping
• PRO

  Mick Gammage November 3, 2010 at 5:05pm

  This was discussed back in June
  
  "How important is Permeable Paving"
  
  I have not come across a situation in the last 2 years since the new planning legislation where Permeable Paving would be the only option, there is always a solution using traditional block paving with drainage channels and a soak a way if you know what your doing and like wise I do not want to discuss my methods on an open forum