Dry or wet bedding mix? - Indian sandsone flags

[andyfr]

In the past I have used a dry mix to do some utility areas and as I used a fairly strong mix they have been fine. I have 50 sqm of Indian sandstone to lay and have started by doing the steps and for this I used a wet mix and that is also fine.

I'm now trying to decide which is the best bedding to use for the rest of the patio. Can someone tell me the pros and cons please?

[Rich H]

IMO the stronger the mix the more water you need. This is because the cement uses the water as it reacts. If you don't have enough, the mix can dry out before curing enough to bond to the slab. I like to use a ratio of about 4:1 with the slump set to just about bind but also break up easily. Indian sandstone is pretty 'thirsty' so better to be slightly too wet than too dry.

[andyfr]

Thanks for that Rich!

So it looks like it's a wet mix. I must admit that I thought it was easier to bed than when I used a dry mix.

[Bobby Spray]

Just finished 50m^2 of indian sandstone. I did try a semi dry but it's hard to consolidate down if too dry. A squirt of fairy in the mix also made a huge difference to workability.

[andyfr]

Good tip! Must pinch some Fairy...maybe I should rephrase that!

[Jason Herring]

My 2p worth.. I use a measured (14L bucket), plasticised 3:1 mix. Wet. Trowel in around the edge of the last piece you laid then in to the bed. Fill where the joint will be before you lay the stone. Gently push the stone in to place (a few taps with a rubber mallet if you can't push with your hand) and you have a 3:1 joint completely consolidated on a full bed - no pointing needed and it won't come out. You never get a rocker. They are easy to place and once you take off the excess pushed up in the joint and strike off the top of the joint it's done. Move on to the next piece.

[lutonlagerlout]

fairy liquid!!! sacrilege!!

sbr or pva ftw!

i like a wet mix for indian stone myself,as jason rightly says,no rockers,
never did get on with dry mixes
mind you its September now and i haven't laid a new patio this year ,only repairs etc
LLL

[andyfr]

I think I might have some Wickes Mortar Plasticiser in the garage, that would do wouldn't it?

[Pablo]

Just finished 50m^2 of indian sandstone. I did try a semi dry but it's hard to consolidate down if too dry. A squirt of fairy in the mix also made a huge difference to workability.

hang your head in shame

[Jason Herring]

Fairy will plasticise but will also weaken the mix. The green dye in Fairy can also change the colour of the mortar.

"Feb" or "Addmix" is just as cheap and won't make air bubbles that Fairy can.

A 25L drum of Feb from B&Q is about £15. That'll last for over 200 bags of cement if you add a 125ml per mix to each bag of cement.

[lutonlagerlout]

Fairy will plasticise but will also weaken the mix. "Feb" or "Addmix" is just a cheap and won't make air bubbles that Fairy can.

can you repeat that in English please Jason??
LLL

[James.Q]

fairy isa no no :p

[Mikey_C]

yes the "Wickes Mortar Plasticiser in the garage" would be perfrect in the mix. Definitely not fairy or any other much cheaper washing up liquid.

[andyfr]

Just have to wait for dry weather. Last weekend I laid...wait for it...three flags! Small ones at that. Tried to lay a fourth one three times before giving up due to the heavy showers.