"Iain Robinson" wrote in message
...
I posted here earlier in the week and some kind souls pointed me in the
right direction, clarifying what I should lay my patio on. But I need a
bit more clarification please.

After whacking down my sub-base I am putting down a drymix mortar to lay
the slabs onto. It seems one part cement to four parts sand is the right
ratio - correct? I had read that the sand for patio work should be sharp
sand (as it 'locks' in place) but I see that pavingexpert.com recommends
that soft sand be used for mixing up mortar. Which is correct? If it
should be soft sand what would the result of using sharp sand be? I have
already ordered the (sharp) sand. I went through what we wanted to do
with someone at the builders merchant and he seemed to agree that we
were on the right track, so hopefully this is not our first stumbling
block.

1:4 is OK, you could go for a weaker mix if you like. Sharp sand is OK too.
I
don't know what advantage could be gleaned from using soft sand in this
application. Soft sand is usually used for bricklaying or pointing as it
makes
the mortar 'handle' well. Am I correct in assuming that by 'drymix' you mean
that you lay down a dry mortar mix, place the slabs on top, then let
atmospheric
moisture set it over time? If so, then its wet properties won't even be an
issue.
Sharp sand gives a stronger material, which is not so easy to manipulate
( in a wet mix state ) as mortar made with soft sand. If you have to use
sharp
sand ( because you have lots of it lying around! ) for wet work i.e.
bricklaying
or laying slabs on a wet solid bed of mortar, a little plasticiser in it
will improve
its workability tremendously.

I was also recommended to put down extra cement at the sides of the
patio to keep the sand in - should this be pure cement (put down dry, as
the mortar?) or just a mortar mix with a higher ratio of cement in (if
so what ratio).

Never use pure cement on its on. It will crack. Use 1:4 again. The highest
ratio you can use is 1:3, but this is a strong mix, and is only suitable for
stone walls etc. 1:4 is plenty strong enough to keep sand fro escaping your
patio. To give you some idea of mix ratios, 1:3 is the strongest useful mix,
1:4 is OK for mortar, 1:5 is an appropriate mix concrete made with
3/4"-to-dust
ballast and you can go down to 1:6 in low strength applications ( behind a
firegrate as infill etc. Any weaker and it will get sandy over time in
exposed areas.

Apologies for the dumb questions but this is all new to me. I have this
week off work this week to do this - I want to be sitting on the patio
having a beer by Friday. In any spare moments during the process I also
have to decorate the kitchen........

Many thanks,
Iain

Remember that cement is as caustic as oven cleaner, wear gloves, especially
if you
are using it wetmix, otherwise you won't have any skin on the tips of your
fingers at
the end of the day.

Andy.