Filleri excavated too much... - Advice on filling

[Simsy]

Folks,

Thanks in advance for your time...

I've started work on a Patio. Having previously successfully made a block paving path round my garage, and block paved my front garden, making it into a small drive, (having found this site half way through!), I thought I'd be OK doing it myself...

So far so good. The original intention was to block pave the patio, making use of my previous experience, and with the help of a couple of mates I dug out with this in mind. I now realise that for a patio I've completely everdone the excavation, and to slightly exacerbate it we've now decided not to use block paving, (as we don't want the patio to look like a drive!), but to use flags instead.

Anyway, the excavation is finished, and I've got all the edging in place, on concrete...

The problem is that even using all the small bits of concrete and bricks, and old bits of paving that I had, that didn't go in the excavation skip, to fill up the body of the area, I'm still well short of a lot of material. I was going to get a couple of jumbo bags of crushed concrete, (which I've heard of, but never actually seen!), to fill up the bulk of the area, then top this with a couple of bags of MOT type 1, then my sand bedding...

However neither of the two builders merchants near me do crushed concrete, they only do MOT type 1... As a result I'm expecting to use just this to fill the hole... this means the MOT layer will be about 5 inches deep, (without compacting), under the sand.

Is there any problem using this thickness of MOT, and do I need to compact it with a "whacker", bearing in mind it will be slabs, not blocks, on top.

The site, ready for the next stage, can be seen here;

http://www.simsy.plus.com/Edge/patioedge.html

You can see the path I made 7 years ago, at the back of the garage, where it meets the new patio.

Thanks in advance for an advice. I'm hoping to order the MOT very soon... probably later today, (26th June), so any advice not to do this would be welcomed quickly!!

Regards,

Simsy

[Tony McC]

The Type 1 needs to be thoroughly, very thoroughly compacted before you get to lay the flags. To achieve thorough compaction of 125mm of Type 1, you need a beefy plate compactor, not one of the farty lawnmower types often hired out for 30 quid by the hire centres.

As you won't need a plate to compact the flags, you might be better off hiring a rampactor to consolidate the sub-base material, as this would have no problem bashing down 125mm of Type 1, and doing a much more effective job than a lightweight plate.

[Simsy]

Thank you.

I take it then that this depth of MOT type 1 isn't a problem.

I can see that to compact all of it in one go would be difficult, so I'm thinking of laying/compacting, in 2 runs; lay 2 inches, compact, then lay the rest and compact again. Is this a bad idea? I was planning on using a plate compactor at the sort of price you mention.

I'm not sure what a rampactor is? I've had a quick search online at local hire places... none mention a "Rampactor" Access would be through a 1 metre wide gate. would it fit? What sort of cost, if I can find one?

Thanks for your time.

Regards,

Simsy

[Tommy]

Is this is elusive 'rampactor' Trench Compactor

[Tony McC]

Yep: I posted a pic a few weeks ago...somewhere...



...should be able to get them from those luvverly people at Speedy Hire... yes, they call 'em "Trench Rammers", page 59 in the catalogue. 37 quid for a day but you should be able to haggle them down to 30.

Anyway: back to compacting. While it might seem a good idea to compact in 50mm layers, you'll struggle for the reasons outlined here. If poss, using a rampactor with 100-150mm of sub-base at a time will give superb results, but if you must do 50mm lifts with a plate compactor, it's still better than nowt.

[Simsy]

Thanks very much for that.

I've got the MOT coming tomorrow, and I've hired one of those gizmos from my local hire shop for Thursday. (£34 for the day)

I've got about 17 sqMetres...

I'm guessing that I should be able to get it compacted in a day ok... shouldn't I? The "foot" of the compactor doesn't look very big.. about 10" by 6"

Do I need to be concerned about how near I get to the gulley collecting the sink waste? It's clay, but well shrouded in concrete.

Thanks,

Regards,

Simsy

[andpartington]

the trench wacker will knock 7 bells of hell out of the pipe stay away i would stay away if possible
it will make the whole house shake and is a lot of fun if you can get it going (or was it just mine)
just don't go over your toe with it

andy

[Tony McC]

In a day?? It should only take 20 minutes ... buut then it'll take the remaining 7 hours and 40 minutes for you to stop shaking! :p

[Simsy]

Due to domestic happenings I couldn't pick the wacker up today... hire shop are happy with that... hopefully I'l be able to do it tomorrow!

A couple more questions if I may indulge you...

I think I may have overordered the MOT type 1... I got 4 jumbo bags... I've used 2, and that's covered about 3/4 of the area... I reckon it'll take about another half bag to cover the rest...

Now bearing in mind this is uncompacted I realise that I'll need to use more... In terms of height, how much does it compact when I use the wacker... It's roughly 4-5 inches thick at the moment... what will this whack down to?

Should I just use it all and whack it? If I do that and it end up too high, can I reduce the thickness of the sand/cement bed that the flags will go on? I'm currently basing things on a 2" thick bed.

Thanks for all your help.

[Dave_L]

Hold on tight to that whacker!!! Go any loose fillings? You soon will have!!!!

We call ours "Jumping Jack"