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Posted: Thu Mar 27, 2014 1:49 am
by dastrix
Hi All
I'm new to the forum here in Sydney and am considering laying approx 50sqm of 30mm limestone pavers. These are a french pattern which are honed and tumbled, so the edges are rough
The sizes are
600x400
400x400
400x200
200x200
The area is currently dirt and I'm hoping you can critique the method or offer suggestions.
The area has OK drainage but will have a surface/linear drain installed.
Install:
Compacted road base, 100m thick using 5% cement and wetted. Will use a whacker packer over the area, packing it in 2 lots of 50mm.
Full Wet mortar bed
The pavers will be close jointed, because the edges are tumbled there are really no sharp edges.
Is this method OK for pedestrian traffic only? I've attached some photos of the area and also the pavers just laid on the ground.
I will be sloping away from the house into the drain for water run off. Im aiming to use the mortar bed because i dont want weeds or ants or movement.
Questions:
What mortar mix should I use? My pavement is quite 'light' in color, is there a particular sand/cement I should use?
Can i just sprinkle my cement ontop of the road base as I compact it to increase the hardness of the base?
Do I need any expansion type joints?
Given its a large area, i wont get it all done in 2 days, can I do half of it and come back and continue it over a few days? I will of course prepare the road base area in one go.
Thanks
Kris
Posted: Thu Mar 27, 2014 2:49 am
by lutonlagerlout
Hi Kris
welcome to the brew cabin
at least you are on the right tracks
the mortar should be around 6:1 , grit sand :cement
I fear you are talking about butt jointing your flags
it rarely works better to aim for a 10 mm joint which can be pointed with either resin or cement
the only other thing I can see is your steps on your nice wall may be wrong by the time you build your patio
cheers LLL 
Posted: Thu Mar 27, 2014 3:00 am
by dastrix
Gday!
Is Grit sand known by any other name? Not familiar with that down under.
Yes, butt jointing as seen here (this is the same stone thats been laid elsewhere on crushed dust)
https://farm8.staticflickr.com/7220/13438958813_38fb2d0c8e_o.jpg
Sorry, apologies, that photo shows the dirt level quite high. Since that photo its been excavated a fair bit
The top of my stone is to be in line with the bottom of the first retaining wall block, so, it should be oK
Posted: Thu Mar 27, 2014 3:27 am
by lutonlagerlout
grit sand is sand that would be used for making a floor screed
it has mall pieces of grit in it less than 3mm
that job looks pretty good but butt jointing generally is a bad idea
however different countries use different approaches due to climatic reasons etc
I am guessing you dont get rain like we do??
:;):
LLL
Posted: Thu Mar 27, 2014 3:38 am
by dastrix
These pavers it turns out are not designed to have a joint, the pattern doesnt allow it so they are designed to be butt joined.
We are in Sydney and yes, we dont get rain daily like you do in the UK
I think we just call that 'Sydney Sand' its a washed medium sand
http://www.bcsands.com.au/landscaping/sand
http://www.bpsaust.com/washed%20sydney%20sand%20bps.html
Posted: Thu Mar 27, 2014 4:31 am
by lutonlagerlout
out of the 2 the river sand looks better for the base material
the washed looks more like plastering sand
if they are designed to be butt jointed go for it!
there arent many butt jointed products in the uk that look good
unusual to see natural stone butt jointed but when in rome.....
LLL
Posted: Thu Mar 27, 2014 8:04 am
by Tony McC
You can get away with close jointing, keeping a 2-5mm gap, and it should impact on the layout too much, certainly not enough to cause problems, and it helps accommodate any dimensional discrepancies in the stone, which always occur, no matter how accurate the supplier claims to be.
The resulting close joint is filled (usually) with a fine sand, which improves interlock and prevents any horizontal rotation or movement.
What mortar mix should I use? My pavement is quite 'light' in color, is there a particular sand/cement I should use?
Have a read of this page for guidance on working with light/pale natural stone flags. You might be well advised to select a 'silver' sand and use white cement. I'm not sure what sands are available in your country, so you may need to hunt around to find a suitable candidate, which should....
1 - have a very low iron and/or clay content
2 - have a grain distribution from 4mm down to dust
3 - be exceptionally free draining
4 - have angular rather than rounded grains
Can i just sprinkle my cement ontop of the road base as I compact it to increase the hardness of the base?
But that doesn't actually increase the hardness of your base. It forms a flimsy crust on top of your hardened base.
Do I need any expansion type joints?
It depends on the layout. Generally speaking, you should be OK without any full movement joints, as there are so many unbound joints between the individual flagstones which would accommodate minor movement, but there's no harm in creating such joints within your base if only to keep to the 30x thickness rule-of-thumb
Given its a large area, i wont get it all done in 2 days, can I do half of it and come back and continue it over a few days? I will of course prepare the road base area in one go.
That's how we work on larger jobs. You can't always pave the whole area in a single shift so you need to cover the area in stages. The key thing is to make sure any open edges are retained in some way at the end of each shift to prevent accidental movement, and then to check these edges again at the start of the following shift to make sure there hasn't been any slippage or movement, despite the measures taken to minimise its occurrence.
Posted: Thu Mar 27, 2014 9:11 am
by dastrix
Thanks Tony for the feedback and clarification on my questions. We had a old school tiler/stone mason visit this afternoon who recommended the roadbase approach and a mortar bed using triple washed sand. I am still considering getting a pro to do the job
He also said what you mentioned, a slight 2-4mm gap for grouting. He said he'd use a flexible grout joint. With that, theres no need for expansion joints etc.
He also mentioned 50mm mortar bed which is about on the high end of your recommendations for the thickness of the mortar, so thats in spec too. I've just found it difficult to get really sound information from tradesman (here in Sydney, there are ALOT of dodgy ones!!)
I did have a read of your page re: light colored flags/stone. I will try and use a sand like you mentioned for the grout
Thank you!
Posted: Mon Mar 31, 2014 9:58 am
by Tony McC
I'm surpised at the suggestion there are lots of cowboys down there in Sydney. The Aussie pavers I know all reckon they have to be registered, insured, and prove their qualifications before they are allowed to trade, unlike here ion Britain and Irelanbd where any under-employed taxi driver can set up as a 'builder', 'pavior' or 'landscaper' if they fancy a few months in the fresh air over the summer.
