Paving a pathway - some questions

[PacoLoco]

Hello all,

I am planning to lay some paving slabs on the path that leads to my front door.
Currently the path is concrete so the slabs would be laid directly on top of that.
I've read a few guides on laying slabs but still have some questions:

- I have some spare bags of premix bricklaying mortar - can this be used to lay the slabs with?
- I also have some spare bags of Postcrete (quick drying concrete) - could this also be used to lay the slabs?
- Once the slabs are laid could I use the bricklaying mortar to point them? If so would this best be done with the mortar dry and then water it with a watering can (as I've read in some guides), or should I mix it up as normal and then point with it?

Thanks in advance, P

 

[xdave]

I wouldn't use the postcrete - it will flow off the sides of the base and be unworkable before you've levelled the slabs.

The bricklaying mortar may be ok to lay on, but I'd save that for the jointing and apply it mixed with water to a semi-dry play dough consistency. Use a bit of scrap cardboard against one edge as a mortar board and work it in with a small trowel and it won't make any mess. Brush off any excess when returning later to point so as not to stain the slabs with wet mortar. Don't apply it dry and water it in for paving installed on a wet base or your jointing mix will be inconsistent and be coming up again after the first hard winter.

For laying the slabs a standard general purpose mix with sharp sand and cement will be fine. Either use a cement with a plasticiser added (e.g. mastercrete) or add some with the water and use a cheap float to level it out. If you use building sand it tends to be a bit sloppy and hard to level the slabs. It also tends to come out the sides if not shuttered, whereas the sharp sand mortar/concrete is a bit more stable.

The pavingexpert.com web site has loads of good information on laying any sort of paving you could wish for.

 

[PacoLoco]

Thanks for the reply - that's very helpful.

When you say a "general purpose mix", do you mean 3 parts sharp sand to one part cement?
Also how thick does this layer need to be? I'm thinking about 20mm - is that enough?

 

[xdave]

4:1 is normally ok for laying paving unless you plan to drive on it, in which case you could use 3:1.