DIY - Re-laying Indian Sandstone patio

[KMax18]

Greetings!
We have an Indian sandstone rear patio (probably a few years old, from before we moved to the property). Some slabs were rocking and had moss/vegetation growing in the pointing. Decided to have a crack at re-doing it myself.

- Have lifted the slabs, chipped away the old multiple cement spots and brushed off the loose sand.
- There is a concrete underlying base, on which I want to re-lay these same sandstone slabs and re-point.
- I bought Tarmac Multi-purpose Mortar Mix (25 kg bags) from Homebase.
- Probably didnt do too well with the mortar mixing, leading the slabs not sticking and could be lifted off easily in 2 days
- Removed this recently laid mortar which was often a bit crumbly. Few areas were quite rock-hard.. very inconsistent.

- Question -
(1) Should I pursue with this Tarmac ready-mix mortar and get a good wet mix to lay the slabs on? (thinking of hiring a cement mixer)
(2) Buy building sand/cement/plasticiser and make the wet mix from scratch (4:1) using a cement mixer?
Or
(3) Would a semi-dry / moist-mix do the trick (screeding) - though I have my doubts on this one

Planning to point this with "Easy Joint paving grout" as a wet slurry mix.

Appreciate your thoughts -- Images attached. Thanks for looking.

 

[Brigade77]

You won't get 2 answers the same to any question you can ask about laying flags.

Spend a few mins here : http://www.pavingexpert.com

1. When you're happy the sub base is OK, lay your flags onto a wet mortar of 6-1 sharp sand & cement. This layer needs to be approx 40mm deep. I don't do dry or semi-dry mixes, I like my flags to move when I tap them when laying. NOT whacking seven bales out of 'em with HUGE mallets & risking breaking them or worse . . . cement voids !

2. Butter the flags & point them as you go. This way the pointing will be thoroughly integrated & last for years.

3. Find the man who laid those flags using the dot method, shoot him & bury his lifeless body under your newly laid flags. This way he can do no more harm.

 

[r896neo]

The mortar mix you bought is for laying bricks. Its not really right for flags.

Follow dorks advice its pretty spot on.

Personally I prefer to point afterwards and if your a novice flag layer I would do the same. Worrying about jointing and butter in as you go will slow you down to a snails pace.

 

[KMax18]

Thank you so much for your replies Dork Lard, r896neo ... Much appreciated.