Laying slabs on existing bed.

Patio flagstones (slabs), concrete flags, stone flags including yorkstone and imported flagstones.
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BillK
Posts: 3
Joined: Sun May 14, 2006 7:54 pm
Location: Bucks.

Post: # 11949Post BillK

I am about to start to lay my Indian Sandstone path and patio and have a couple of questions. Firstly, I have removed my existing slabs and I'm left with the concrete base they were laid on. Do I need to break up and remove this layer or can I lay my new slabs and 10:1 mix on top of it?
Secondly, do I need or is it a good idea, to seal the surface once laid? If yes, what should I use?
Thanks in advance for any advice.
Cheers,
Bill.

BillK
Posts: 3
Joined: Sun May 14, 2006 7:54 pm
Location: Bucks.

Post: # 11950Post BillK

Sorry,one more thing. Is grit sand the same as sharp sand?
Cheers again.

Mark B
Posts: 86
Joined: Fri Feb 24, 2006 12:37 am
Location: Hamilton, Scotland

Post: # 11951Post Mark B

yeah, grit sand is the same as sharp sand, in some areas also known as concrete sand

mark

BillK
Posts: 3
Joined: Sun May 14, 2006 7:54 pm
Location: Bucks.

Post: # 11956Post BillK

Cheers Mark, can anyone help with first question?

Cheers,

Bill.

Tony McC
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Location: Warrington, People's Republic of South Lancashire
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Post: # 11991Post Tony McC

The advisability or otherwise of laying over the existing concrete all depends on levels - see this page
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Alex
Posts: 7
Joined: Tue Jun 13, 2006 10:51 am
Location: UK, Lancashire

Post: # 12355Post Alex

Hi All,

I am in a similar situation, I removed some concrete flags and tried to increase the paved area. It looks like the flags were already on a 10:1 mix or something that is relatively strong and is still very firm. I have a couple of questions:

1. I wanted to use Indian Flags, and lay these on the already used base and the new bit that I constructed with about 3" Scalping and 2" sharp sand. Is it Safe to simply plat compact this to make the "new" area firm or is it better to mix it 10:1 and then plat compact it?

2. I read the section on this site advising to butter and create the pointing straight away. Since I can only do this job on weekends and in evenings – is it safe to lay stones in small sections and point them all at the end – to make sure that the colour is same (I am hoping to use a black colouring agent to go with blue/gray stone)?

3. (In case it all fails) I have about 50sqm to lay and I wondered if it would be best to leave a professional to do the job - all the hard work has been done now - the ground is ready for the actual laying of the stones in a three stone design. Can anyone suggest if there is a guide on how long it should take a competent contractor to lay 50sqm of Indian stone and what is an appropriate charge?

Thanks for your help

Alex
;-)

Tony McC
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Post: # 12365Post Tony McC

1 - so: you have an area ofd conrete-like material and an area of granular sub-base and you plan to pave the lot? Is that right?

If so, it's less than ideal because of the potential for a phenomenon known as "differential settlement". However, this is more of an issue on large commercial projects rather than patios, so I'd be tempted to ignore it and rely on laying ALL of the new flags on a 10:1 mix and trust that it will be adequate to support the lot.


2 - Butter the flags, and then when you have them spaced as required, use a flat pointing tool or the edge of a trowel to ensure the butter mortar is well pressed down into the joint, leaving a minimum of 25mm depth for the eventual pointing or alternative jointing which you can do at the end of the job.

3 - A good contractor will lay 50m² in 2 days and charge somewhere between 500-1200 quid, depending on how good their work is, where you live, and how badly they want the job.
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Alex
Posts: 7
Joined: Tue Jun 13, 2006 10:51 am
Location: UK, Lancashire

Post: # 12418Post Alex

Hi Tony,

Yes you're correct that's the situation about the bases.

We have had thrtee contractors in to look at the job and give estimates. All said they would need to use a base of sand and cement and some were saying 1:4 and 1:7. They quoted the job would take from 1 - 2 weeks. Cost varied from £150 a day to £250 a day. We are now considering doing it ourselves since we have done a lot of the hard work already. One concern that we have is that they all want to have a stiffer mix than 1:10.

We'd be very grateful for your advice - is it worth going to the expense of mixing 1:4 thanks a lot.
Alex
;-)

alan ditchfield
Posts: 203
Joined: Thu Jan 01, 1970 1:00 am
Location: Preston / Lancashire

Post: # 12425Post alan ditchfield

Where abouts in lancashire are you Alex i would be happy to give you a quote, as for the expense of the extra cement you would only need about 15-20 bags to do the job thats 45-60 quid giving you a rough mix of 8-1

ken
Posts: 274
Joined: Wed Feb 25, 2004 10:07 pm
Location: Leigh, Lancs

Post: # 12430Post ken

is that the same alex i saw in exton near chorley on thursday? if so, id have a crack at laying the sand stone your self using the gidelines on this site, you got all the prep work spot on, so im sure you could get the rest right. good luck. ken
Ken

KGC Block Paving

Leigh Lancashire

T:01942 601781 M:07989 376123

Alex
Posts: 7
Joined: Tue Jun 13, 2006 10:51 am
Location: UK, Lancashire

Post: # 12490Post Alex

Hi Ken,

Yes it is me. This world is very small. Thanks for your time again.

I am a bit concerned about doing it entirely on my own since it is a rather big job for a beginner – I already misunderstood the instruction – putting a bed of grit sand without any cement 8-( and expecting to put the slabs simply with a bit of buttering.

Alex
:D
;-)

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