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Posted: Sun Jun 20, 2010 1:58 pm
by Cmaster
Hi. Would like some advice please and to make sure I don't need to do more then I need to.
I am going to do a bit of slab laying but am a noob and never done it before. I did get a quote in but at £850, is far to much for the job, so am going to try myself. I did have a quick read of your website but am unsure on some things. I don't think I need to do some of the things you talk about.
There are slabs layed around the edge of my property and a long a partition wall. They have been there for about 45 years. Then someone has made it a bit wider. What they did was very untidy and look a mess. So I have taken them all up. I am leaving the 45 year ones down. Please see pics. I have some large slabs that I will cut down the middle and lay them longways. My question is, do I need to put down a sub base or can I just use sharp sand? There is sand already down, do I need to remove it or can I use it again?
If I have to use a sub base, can I use this? http://www.wickes.co.uk/Granular-Sub-Base/invt/224664
what about just ballast. http://www.wickes.co.uk/Ballast/invt/220111
Are bags of small stones any good?
Pictures here.
http://i120.photobucket.com/albums/o199/Noname150/STA41734edit.jpg
http://i120.photobucket.com/albums/o199/Noname150/STA41733edit.jpg
http://i120.photobucket.com/albums/o199/Noname150/STA41738.jpg
http://i120.photobucket.com/albums/o199/Noname150/STA41737.jpg
Thanks.
Posted: Sun Jun 20, 2010 3:43 pm
by local patios and driveway
i think the only advice you will find on this site is from pro's who will advise you to do the job properly, ie proper sub base. the slabs you want to leave are crap, take them up. also the wickes bags you are looking at will be hella expensive, you need to be thinking about the bulk bags of MOT instead, i would then be looking at laying your new slabs on a thick concrete bed
Posted: Sun Jun 20, 2010 4:26 pm
by Cmaster
Thank you for the reply Digger. Well I hope I can get some more advice here but if not, is there a forum to help me with this?
As for the old slabs. I agree and would like to take them up but I can't. One it would be a hell of a lot of work and more than I could afford to do. Plus I don't own the property. I can do what I am asking about but not remove the old slabs.
I have taken a few more pics and dug down a bit. Looks like some black stuff with sand on top. What is it?
http://i120.photobucket.com/albums/o199/Noname150/STA41745.jpg
I have lifted up one of the old slabs that were not fixed. Does it look like it is on mud?
http://i120.photobucket.com/albums/o199/Noname150/STA41740.jpg
I did a quick search on google and found these instructions.
Wrap a string line around two bricks or pegs and stretch it across the area where you plan to build the foundation.
Use a spade to remove the turfs and the topsoil where you plan to build the foundation.
Dig down to a depth of about 20 cm (8 in). You'll need this depth to fill in about 10 cm (4 in) of hardcore, 5 cm (2 in) layer of sand, and the layer of concrete or paving material.
With a sledgehammer or a garden roller, compact the base of the trench.
Next, add a layer of hardcore to the base, which should be 10 cm (4 in) deep.
Compact it with a sledgehammer or a garden roller.
Spread a layer of builder's sand of about 5 cm (2 in) deep.
Smooth the surface with a garden rake.
Next, add the concrete on top of the builder's sand.
Tamp down and flatten the layer of concrete with a piece of timber. The piece of timber should be long enough to span the area.
Let the foundation set and dry before starting your next project.
[quote]
http://www.ratedpeople.com/m....on.html
Posted: Sun Jun 20, 2010 5:15 pm
by lutonlagerlout
I don't think I need to do some of the things you talk about.
why ask then? ???
I have seen the same detail as you have there around 1960-70s schools,they were laid on sharp sand which has long since run away
the slabs you are talking about leaving negate any new work you intend to do
they have sunk
couple of hours tops to take them up then start afresh
the methods described on this site are to british standard
if you need a cheap bodge ring tommy walsh :;):
LLL 
Posted: Sun Jun 20, 2010 5:17 pm
by lutonlagerlout
btw rated peoples tip doesn't make 1 iota of sense
why would you have sand between the hardcore and concrete?
LLL
Posted: Sun Jun 20, 2010 5:45 pm
by mickg
and you certainly would not use building sand as when building sand gets wet it bulks it up in volume and the flags will move over a period of time
building sand is for one thing only......building, as in laying bricks
Posted: Sun Jun 20, 2010 6:22 pm
by Cmaster
lutonlagerlout I thought that your website info was for big jobs and not something as small or simple as mine. The last thing I wanted to do was, spend all that time making a sub base and all that, only to find out it was not needed. So thats why I asked. But I still have not been told if it's really needed.
Well looks like I will have to do it this way. I will follow most of the instructions from that website but use sharp sand. The bit i can't understand is, the bit on your website where you say, 1 part cement.
Can I not get something like that all together and not mess round with mixing sharp sand and cement. It's to complicated for me.
If all I need to do is put some dry cement powder onto the sharp sand, then thats better. Will it hold down the slab though.
Can I not just get a tub of cement from homebase and just mix that and use it?
Posted: Sun Jun 20, 2010 8:12 pm
by mickg
its as simple as this.....
get 2 plastic buckets, fill each of them to the top with sharp sand and either empty into a wheel barrow, a cement mixer or on a plywood sheet
repeat as above
fill one of the buckets up to the top with cement
mix these 5 buckets of sharp sand and cement together and you will have a 4:1 mixture
make a hole in the centre of the mixture if your mixing by hand and add water a little at a time
add just enough water to bind all the sand and cement together without making it look like the consistency of pea soup, in other words get a handful and when you squeeze it stays in a ball in your hand and does not drip through your fingers
place the mixture of sand and cement as a full bed where the flag is going approx 10 - 15 higher than the finished height of your line, this height will depend on how thick your bed is and tap carefully into position with either a maul, rubber mallet or even the bottom end of a pick axe, if the flag drops lower than your line you will need to lift the flag and add more of the sand and cement mixture
thats how easy it is, alot of the guys who post on here have been doing this type of job for many many years and what is easy for us guys might not be so easy if you have never laid a 3 x 2 flag before
anyway good luck and keep your back straight when lifting these heavy flags
Posted: Sun Jun 20, 2010 8:56 pm
by lutonlagerlout
if there was good ground beneath the existing,i.e. chalk you could exclude a subbase
but there isnt
as mick says its not at all hard knocking up some sand and cement and that if that is beyond you ,you are in trouble
I'll lend you a mixer if you want to drive to luton
so in answer
yes you need a subbase
LLL
Posted: Sun Jun 20, 2010 10:04 pm
by Cmaster
Thanks mickg, thats exactly how you need to explain things like that to me.
I know you can do all that with your eyes closed but it's not so simple for noobs like myself.
LLL Like I said above. It maybe easy for you but not so for someone who has never done this type of work.
Btw I had another dig and it's where I removed one of the old slabs. Well it looks like I may not need a sub base. There is some black stuff about 8 or 9 inches down. It looks like coal. I removed a brick and then the rest was sharp sand. Then the black stuff shows up.
That black stuff was here. Pic from before
http://i120.photobucket.com/albums/o199/Noname150/STA41740.jpg
Can you reuse sharp sand or need new?
Posted: Sun Jun 20, 2010 10:22 pm
by rab1
for the price of sand just use new
Posted: Mon Jun 21, 2010 10:15 pm
by Cmaster
I dug down to the bottom today and in the pic, you should just see the black base.
http://i120.photobucket.com/albums/o199/Noname150/STA41751.jpg
That must be the sub base right? If thats the case then I only need to fill the rest with sharp sand?
