Working with falls

[J McNulty]

Hi paving experts,

When building a patio it should have a small fall to help it drain.

When laying the slabs are you better laying uphill or downhill or is it not really important?

Any special tips to keep go a consistent fall and avoid getting too strong a fall and ultimately running out of fall?

Slabs are heavily riven so hard to take accurate reading from string line.


Cheers

[lemoncurd1702]

Work from the house and from the highest point. I usually allow 20-25mm fall over 3m, probably 25mm if they're that heavily riven.
If the laying pattern is coursed then a string line is best and a bit of judgement if they are very riven. Keep checking the falls with a level.

It's easier if you lay an edging detail with a paving block or similar running to the falls then just stretch the string line across.

[J McNulty]

Hi lemon curd,

The Mrs picked the slabs and to make it harder it's they're going to be random pattern. That's why I think with them being heavily riven and not laid courses it will be tricky to follow string line.

Will follow your recommendations.

Wish me luck.

Cheers

[lutonlagerlout]

J even random can be laid with lines
if the module is 300mm set your lines every 310mm
if its 280 module set at 290mm and keep going

we use 1 line either side set to falls then ping our transverse line from this
i would go 1:60 for heavy riven flags
with riven you will always get the odd spot that catches water
LLL

[lemoncurd1702]

If I'm laying a random pattern I set a false edge using a steel bar/scaffold pole and use a straight edge to level the slab as below.

Luton, with your method are the lines set up either side of the paved area with another line stretched between them?

[lutonlagerlout]

yes mate
problem is most want the whole area paved side to side so its not always easy to set up a profile

that poor lump hammer :;):

LLL

[J McNulty]

Thanks guys.

So, the moral of the story is string lines will work but take a little extra effort and it will pay off. Cool.

Out of curiosity...... Is there a general consensus on what's easier to lay, riven slabs or totally smooth slabs?

Cheers

[mickg]

levels, string lines and aluminium straight edges are essential when laying paving

if its coursed both are the same to lay, if its a random laying pattern smooth are a little bit easier only because the lines will stay flat because there is nothing to get in the way

I used to use a lump hammer like you LC as I was taught that way, I used to listen to the sound of the flag when you tap it down, now rubber mallet all the way

[lemoncurd1702]

The handle 8 months on is a little shorter now and impossible to use as a hammer.

I've tried rubber mallets but can't get on with them. They don't have a positive feel and give no feedback. It could also be the handles always seem to be a tad thin also and difficult to control.

[mickg]

I know what your saying it took me a while to get used to the change, using the lump hammer it was more like a tap tap and the flag was bedded, now it takes a few more taps using a mallet

I have 3 different size mallets but always choose the largest for the weight and speed