Will a second compaction fix problem

[jonsey24]

Hi after having my driveway installed back in October using 150mm Barleystone kingspave cobble effect blocks i have noticed it has started to dip and bow in certain places, this only seems to have started since the cold spell accompanied by snow the other week, the drive is not horrendously bad but now i know there are discrpencies in it i am beginning to become annoyed as my eyes are automatically drawn to them when i come out of the house.
My drive was laid on 150mm MOT with a screeded bed of 40mm sand at each stage it was compacted twice before blocks were laid then sand brushed in and given a final compaction.
What i want to know is if the movement in the driveway has been caused by the bad weather, and if so will another pass of a wacker plate iron out these discrepencies and return my drive to normal or will it be a case of lift the damaged area and re lay

[jonsey24]

Anyone?

[mickg]

if the bad weather was to be the reason for any movement in the driveway then it would normally of been higher due to frost heave rather than dipping down

my personal opinion is the MOT should of been compacted more than 2 passes with the vibrating plate but every contractor works in different ways

could you post a photo ?

how to post a photo

[digerjones]

i would let it dry out completly and see what its like in the spring before you decide what your going to do. the bedding sand might not of dried out completly and with the bad frost exspanded the sand. theres more informed chaps on here that will give you the info you need.

[Dave_L]

What he said ^

[jonsey24]

In relation to this the path has got high spots which suggests frost heave as mentioned, the contractor is coming back on Tuesday to take a look and see what the remedy might be

[Tony McC]

... a screeded bed of 40mm sand at each stage it was compacted twice before blocks were laid ....

That doesn't comply with either of the BS methods of construction. If the laying course is effectively compacted to refusal, there's no accommodation for variation in block thickness.

Like everyone else, I'd wait and see what happens after we've had a week or two of thaw.

[jonsey24]

I dont know whether its just me but ive been out again today and the path seems to have settled down again. in your last post Tony what do you mean by when the groundwork was compacted it didnt allow for variation in block thickness? what should of happened?

When the drive was dug out it was done to 250mm deep then 150mm of MOT was used followed by 40mm sand and 60mm thick blocks is this not sufficient

[lutonlagerlout]

it sounds spot on jonesy
i would leave it a bit, sounds like something has frozen and heaved.
the construction sounds great
LLL

[seanandruby]

Light compaction of the bedding layer is all that is required. If it is overcompacted ( compacted to refusal ) there is not as much give in the bedding layer to settle the blocks in, when you rattle them with final cmpaction. Everything else seems to be in compliance.

[jonsey24]

So do you think another pass over the blocks will sort this or am i best getting them to lift the affected area of blocks and compact the bedding sand again then re lay blocks

[Mikey_C]

i would let it dry out completly and see what its like in the spring before you decide what your going to do. the bedding sand might not of dried out completly and with the bad frost exspanded the sand. theres more informed chaps on here that will give you the info you need.

as he said

[seanandruby]

As you state: "it's not horrendously bad," then i would leave it till finer weather. You won't take any notice of it in a couple of weeks.