Advice needed on levelling before limestone flags are laid

[TinyFlat]

Hooray measured yesterday with laser, I have 70mm up to where DPC starts.

I'm going to use a mid-grey limestone (not as dark as kotah - tumbled ash grey) on 21 square meters patio. I am thinking it's easier (?) to use the mortar to joint and I'd like some kind of contrasting colour (light grey or beige?) between the slabs. How do you get the light colour, is it the sand or the cement or both? I'm using 600 x 400 size. If anyone has any suggestions for patios they've created please offer up and tell me what you've used.

 

[Blunt Tool]

Use soft sand, and if you want a sandy cream colour use snowcrete ( white cement) and you can get yellow colouring to get the colour you want. Remember the ratio you use of quantities for a consistent colour or mix dry and more than enough for area. If you want grey it is Portland cement (grey) and soft sand and you can use some snowcrete to lighten. Again remember ratios or dry mix more than enough for area. For pointing a ratio around 2 to 1 or 3 to 1 for soft sand and cement.

 

[Blunt Tool]

Once you mix it dry take a small amount mix with water and let it dry to see finished colour to make sure you are happy with it

 

[TinyFlat]

Once you mix it dry take a small amount mix with water and let it dry to see finished colour to make sure you are happy with it

That's great - thank-you. Think I will go for light grey.

 

[One Day]

Once you mix it dry take a small amount mix with water and let it dry to see finished colour to make sure you are happy with it

Would you add a touch of sbr to the mix?

 

[Blunt Tool]

Would you add a touch of sbr to the mix?

Personally no, messes about with drying. But then if I was pointing limestone slabs I would be leaving mix dry then on a dry day with little chance of rain I'd take a small watering can and wetting the joints with it then using a soft brush sweeping dry mix into joints and compacting to make sure joint is full then sweep away all excess then wait and the water will rise into the dry mix then finish joint with a finishing tool. That way no mess and no stains on limestone slabs! Thats how I would do it

 

[Dumbo]

Personally dry pointing I think I rubbish . How many exterior patios do you see with grout falling out the parts of my patio that I did wet are solid as a rock whereas other parts that were done by my brother in law are falling out . I told him to do it mixed with water but he did it his way because that's how all the builders do it

 

[Blunt Tool]

Personally dry pointing I think I rubbish . How many exterior patios do you see with grout falling out the parts of my patio that I did wet are solid as a rock whereas other parts that were done by my brother in law are falling out . I told him to do it mixed with water but he did it his way because that's how all the builders do it

Never had a problem so can't comment or get into it

 

[TinyFlat]

I'm getting a bit confused about something. Reading on paving expert website and they seem to recommend, sharp sand grit sand or coarse sand to mix with cement. Is soft sand not recommended?

 

[Blunt Tool]

I'm getting a bit confused about something. Reading on paving expert website and they seem to recommend, sharp sand grit sand or coarse sand to mix with cement. Is soft sand not recommended?

Depends what size joint you are going to give them, anything under 8mm soft sand, anything above sharp sand as bulks out joint better. But remember soft sand will give a smooth finish joint and sharp sand a coarser finish joint.

 

[TinyFlat]

Depends what size joint you are going to give them, anything under 8mm soft sand, anything above sharp sand as bulks out joint better. But remember soft sand will give a smooth finish joint and sharp sand a coarser finish joint.

Thank-you. It needs to be soft then.

 

[SJPurdy]

A damp proof specialist will tell you should have your slabs 150 mm below your damp course or you will need a pea shingle gully around your patio .

Hooray measured yesterday with laser, I have 70mm up to where DPC starts.
QUOTE]

So the existing concrete is already 80mm to high and you want to raise it further!

 

[TinyFlat]

The existing concrete is not 80 mm "high". I am talking about the distance between the concrete and where the damp proof course starts. The level of the concrete is 70mm below where the damp proof course starts measured from the highest point of the concrete on the patio and using a laser level.

 

[Dumbo]

The existing concrete is not 80 mm "high". I am talking about the distance between the concrete and where the damp proof course starts. The level of the concrete is 70mm below where the damp proof course starts measured from the highest point of the concrete on the patio and using a laser level.

I think he gets that