How much compaction? - What's the height reduction?

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Simsy
Posts: 22
Joined: Tue Jun 26, 2007 1:48 am
Location: Harefield, Middlesex

Post: # 20239Post Simsy

Folks,

I've now got my MOT down, for my patio, but not yet compacted. I'm going to use a "jumping jack" as per the advice given to me here ...

Given that the MOT is spead at approx 1cm above what would be the ideal finished height when it's compacted, do I need to add more before compaction? (it's approx 4 inches thick all over at the moment)

It's based on laying the paving, (1" thick), on 2" of sand/cement bedding, so I need the top of the MOT to be 3" below the top of the finished surface.

The picture shows the site;

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The reason I ask is that I had delivered 4 jumbo bags and I've used 3. The 4th is untouched and I think I can get the supplier, (Jewson) to take the last one back. (If they don't then they definitely wont be getting the order for the sand/cement and paving!)...

But I don't want to get rid of it if I'm going to need more.


Thanks in advance!
Regards,

Simsy

Dave_L
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Post: # 20311Post Dave_L

Hmmmm seeing those brick edging course there, I wouldn't be too keen to use a jumping jack on that. I'd use a decently big plate compactor. If you aren't used to using a JJ, it would be very easy to inadvertantly hit a brick.

That type1 will go down a hell of a lot more than 10mm - it does vary of course, but I'd allow at least 35-30mm to go down, if not more.
RW Gale Ltd - Civils & Surfacing Contractors based in Somerset

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Simsy
Posts: 22
Joined: Tue Jun 26, 2007 1:48 am
Location: Harefield, Middlesex

Post: # 20329Post Simsy

Thanks.

I'd practise near the middle first, working outward, untill I got the hang of it.

If I do break one of the edgings I've a few spare... but thanks, I'll look out for that happening.

While contemplating other things I got rid of the extra... swapped it for a jumbo bag of sharp sand... looks like I might need another bag of MOT after all!

I'll compact it and see what happens... if it really goes down that much I might need 2 more!

As it happens we've still not decided on the final top surface yet... oh for a decision from her! It might be that we end up with a thicker flag anyway.

Thanks
Regards,

Simsy

IanMelb
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Location: East Riding

Post: # 20340Post IanMelb

Maybe put a temporary section of planking 'edge-on' along the inside of the edging course to provide a bit of a fence that the JJ cannot jump over - it'll bump along it instead.

Simsy
Posts: 22
Joined: Tue Jun 26, 2007 1:48 am
Location: Harefield, Middlesex

Post: # 20342Post Simsy

Good idea!
Thanks.
Regards,

Simsy

IanMelb
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Posts: 417
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Location: East Riding

Post: # 20343Post IanMelb

If you knocked a couple of bits together in an 'Offset-T' then you could rest it on the edging and wouldn't have to dig it in to get it to stand up ...

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Dave_L
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Post: # 20364Post Dave_L

..............aslong as the edges of the stone are nicely down.....

Something you learn as a roller driver.....keep the edges down and the middle up!:p
RW Gale Ltd - Civils & Surfacing Contractors based in Somerset

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Simsy
Posts: 22
Joined: Tue Jun 26, 2007 1:48 am
Location: Harefield, Middlesex

Post: # 20379Post Simsy

Thanks folks.

Good ideas!
Regards,

Simsy

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