Advice to a novice laying a sandstone footpath

[Andy the Novice]

New member, first posting so apologies for any mistakes!

May I first say what a superb site. If copying is the greatest form of flattery then you should be pleased with yourself as many trade web sites appear to use your own editorial!

I am planning on laying a 7x 0.84m path from my front door using Indian sandstone possibly from Rock Unique who seem to have some very good prices and have been very helpful. I plan to use 28cm x 28cm and 28cm x 56cm sized flags with thicknesses varying from 20 –40mm laid in a random pattern. Having read your guidance notes in detail I have set out below how I hope to proceed with the project however as a complete novice any tips and advice would be greatly appreciated.

Plan of attack is as follows.
Dig down 70mm accounting for 50mm bedding material and 20mm for the min thickness of slab.
Lay a dry mix 10:1 sand cement to a depth of 55 - 58mm (5-8mm allowing for compaction although I understand compaction rates will vary) with the top 15-20mm raked to allow for individual bedding of the slab. Do you compact the bed in any way prior to laying the slab?
With the 40mm thick slabs is it OK to be left with only 30mm of bedding on the basis approx 20mm will have been removed from the bedding layer to account for the thicker slab?
Lay each slab individually bedding them down to the required height.
Butter the joints with a class 2 mortar. I am envisaging I would need to be careful with this if the slab is only 20mm thick as the buttering could leave very little space for topping up with mortar when pointing – any thoughts?
As a first timer I can foresee laying each slab taking some time but no bother however with regards to pointing I am left with two choices based on the length of time the project will take. Point as I go ie as each slab is laid so as to ensure jointing is as strong as possible or leave the pointing until the path is completed and accept that a “day joint� between the butter mortar and pointing mortar may exist – any thoughts?
Using your advice I will be using a black mortar so plenty of opportunity make a mess there, I’ll be watching the weather forecast closely!
The path will be laid to a free edge so I am considering using a wet mix mortar at the edges to reduce lateral movement. Do you foresee any problems using a wet mix at the edges with the porous properties of the sandstone?
My final question concerns the aligning the joints when laying in a random pattern. I appreciate that with a random pattern aligned joints should not be common but with only two sizes they will occur more frequently. If I lay two 28x28cm flags with a 1cm joint alongside a 56x56cm flag the result will be a combined joint at the end of the two flags offset by 1cm which won’t look particularly attaractive! Have I missed something blindingly obvious? Your suggestions would be greatly appreciated.

Hopefully I havent't missed anything crucial!

Andy

[lutonlagerlout]

now thats what i call a specification!!!
why not just lay 900 by 600 mm flags straight from the door to the road??
as you do not intend to have an edging these larger slabs weill be more stable and will line up better
i ALWAYS use a string line for laying flags, as we say "the line doesnt lie"
so string a line between your 2 vectors
the bed you mention sounds way to thin and what about a sub base?
we normally go 200 dig ,100mm wacked type 1 ,50-70mm wet bed with the flags tapped down with a rubber mallet (wickes £2.99)
then the next day when they are nice and hard then do all the pointing in 1 go
what is this black mortar you speak of??
it will look cack mate,go for 2 parts soft sand,2 parts sharp sand and 1 part masonry cement for a nice light finish
hope this helps
tony

[Andy the Novice]

It all sounds very straight forward!

I reckon I will go with a subbase as you suggest particularaly as the flags are potentailly relatively thin.

Thought I had read on the site that a black mortar looks better hence the suggestion but if not the simpler the better.

Regarding laying sandstone on a wet bed are there any potential problems with staining the flags and is this avoided with a dry mix?

[lutonlagerlout]

i know a lot of people (the gaffer included) like this dry mix routine and i used it for years ,but since i have used a wet mix.
i have never had a service call for a rocking slab (last 12 years)
obviously it takes a bit of getting used to but in my opinion its a better job
plus you can walk on the path after 2 hours as the type 1 seems to take the water out of the mix
i have heard of people laying dry mix saying to customers "dont walk on it for 5 days"
theres is no reason for mixture to get on the flags,as it is underneath them
the black pointing thing is a matter of taste,but personally i like to see the colour of the flag not the mortar
for me the overall effect is the thing ,plus if you have any kind of accident with the black dye its a night mare
hope this helps tony