Sunken Patio

[NotebookNewport]

Hi
I have a 3*4 m patio that over the years has sunk in a one area about 1 inch across 2 stones. Is this easy to remedy? luckily the are on the edge. what are my options and costs etc.
Thanks

 

[Ian H]

3 bags of grit sand, I bag of cement. £12 and 1/2 hour.

 

[NotebookNewport]

are there any good guides?

 

[Ian H]

I'm not sure. Just lift the slabs and clean them off. Mix a bag of grit with cement, fill the sunken part and knock the slab back down level with a big rubber mallet.

 

[NotebookNewport]

thanks Ian - ready mixed cement? what grit? what mix?
Thanks

 

[Doggit]

You'll always find something on youtube. But Ians used to bigger jobs, so you only need a bag of sharp sand, and a half bag of cement for 2 slabs. it's a 3 to 1 ratio, and you'll put 4 large splodges in slightly from where the corners of the slabs will sit, and maye one in the centre for good measure. You want a dry to slightly wet mixture so that it will spread when you tap the slab with the mallet (or use a wooden block and a club hammer if you haven't got a mallet, and with the aid of a spirit level, or a long piece of wood, you'll be able to get the right level with the existing slabs. Don't use too much force on the slab, or it'll crack, hence why you want a slightly wet mixture.

 

[NotebookNewport]

top man

 

[NotebookNewport]

3 to 1 ratio - sand for gem or the other way?

 

[Ian H]

3 sand, 1 cement. You don't have to be too accurate under a slab so just chuck roughly a 3rd bag of cement onto a full bag of sand, they will all be 25kg bags, sands about £2, cements about £5.

Mix them together in a wheel barrow if you have one, on a board if you don't. Add the water slowly while mixing until you get a nice workable consistency.

 

[NotebookNewport]

Thanks both - I have you both to blame

 

[NotebookNewport]

forgot to say, I have a round manhole cover in the patio with concrete laid around it - now being an expert, I wondered what you call the frame you can get that you place over it and place a cut stone inside it, should it require being removed.

 

[Ian H]

An inset lid? Like this:

http://www.drainageonline.co.uk/Man...anhole-Cover-&-Frame-600mm-x-450mm-x-80mm.htm

 

[Doggit]

You want a recessed manhole cover.

 

[NotebookNewport]

Dug the stones up this morning - looks like it was a sand and cement mix (talking like a pro now) however some areas are rock solid and others are still sand and I guess cement.
Why didn't these areas go off? when you put the mix down should it be watered?
I take it I need to remove the none good stuff
Then what - sand and cement mix dry?
level it?
wet it?
level stones on it? etc
Thanks for your help

 

[Doggit]

Is that building sand, or sharp sand. If it's BS, then that would explain the problem.

I can't see the pictures close up, but it's possible that they've put down a bed of sand, then splodged the cement down, but not in constant amounts. BS would allow the cement to move over time, whilst sharp sand would hold it steady.