Brick paving problem - Movement after traffic use

All forms of block paving, brick paving, flexible or rigid, concrete or clays, new construction or renovation
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taskew
Posts: 4
Joined: Tue Feb 19, 2008 11:02 am
Location: Bournemouth

Post: # 26000Post taskew

Recently laid flexible brick paving is showing sign of movement after vehicle traffic. Joints are opening, individual pavers are becoming loose and sand is dissappearing into the joints. Sub-base is hard tarmac/concrete with a 40mm sand bedding course. Paving is fully restrained at edges. After laying, the paving area is sanded and compacted three times and initially appears firm and well jointed. Jointing sand is kiln-dried to BS 7533. - which is quite fine. The bricks are an irregular "Dutch" type -laid on edge and the manufacturer recommends a coarser grain of sand of 0-4mm. Could this indicate the cause of the problem?

Pablo
Posts: 1990
Joined: Sun Mar 25, 2007 10:49 pm
Location: N/Ireland

Post: # 26010Post Pablo

What kind of sand was used as the bedding course and was it raining when the bed was screeded.It's possible that the compacting plate wasn't up to the job also. Is the course sand recommended for jointing or bedding.
Can't see it from my house

matt h
Posts: 607
Joined: Mon Jul 09, 2007 11:14 pm
Location: gosport

Post: # 26011Post matt h

seems to be a compaction problem,re sand and use rubber mat with compactor again... what weight vehicle traffic?
general builder, maintenance engineer, gas and plumbing installations, extensions etc

Tony McC
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Post: # 26235Post Tony McC

I'm not sure if the OP has disappeared back into the ether, as I would have expected a reply to the comments put forward by Pablo and Matt, but for future reference, there is a real risk of block movement when a rigid or semi-rigid base is used, especially if there is no provision to drain the laying course material. The reasoning behind this is given on this page
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MRA
Posts: 31
Joined: Thu Mar 06, 2008 11:30 pm

Post: # 26294Post MRA

Tony McC wrote:I'm not sure if the OP has disappeared back into the ether, as I would have expected a reply to the comments put forward by Pablo and Matt, but for future reference, there is a real risk of block movement when a rigid or semi-rigid base is used, especially if there is no provision to drain the laying course material. The reasoning behind this is given on this page

Agreed. Also, any future maintance or repair to services could be a nightmare if you need to excavate through a solid base to access pipes or cables.

taskew
Posts: 4
Joined: Tue Feb 19, 2008 11:02 am
Location: Bournemouth

Post: # 26296Post taskew

Sorry for the delay in responding guys - but the paving manufacturer had been to site and promised a report that has now arrived. This tends to agree with most of your comments and the finger of suspicion points to saturation of the bedding course. Its significant that the areas in question were laid the first two weeks in January (very wet if you remember). Subsequent areas laid in dry weather appear to be quite stable. Its a large project and I'll post any further developments in due course.

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