On 27/04/2014 07:20, harryagain wrote:
"James Jones" wrote in message
news


I have some "stepping stones" set in to my lawn: 9x18 cms and also a
couple of paving slabs : 60x75 cms which have sunk.
Is it better to relay them on "blobs" of cement rather than just
trying to get a sand base nice and level. I am think if large blobs
of cement are used it will be easier to get them level by tapping them

down with a rubber mallet. (The paving slabs take no vehicles)

They sank because they are on topsoil which migrates out from under them
helped by worms/moles etc.
Lift them, dig out the topsoil and fill with hard core (any old bricks etc),
tamp it down as hard as you can

So far so good....

and top off with sand.
Don't use any cement, there's no point, it's just a bodge method.

Could I suggest you go read some of the British standards on paving
techniques? To describe using a bound bedding layer (i.e. one containing
cement or lime) as a "bodge" is inaccurate and misleading.

Generally, "sand only" screeds tend to be used for smaller element
paving such as blocks and sets, and screeds with a binder used for
larger slabs - however this is not a hard and fast rule.

However the critical requirement of any sand only screed is that the
edge is adequately retained - typically with a mortared in place bedded
on course of blocks or edging stones, but sometimes just a concrete
haunch. Without the edge restraint, the sand will migrate out, and will
also get migrated by insects. and worms etc.

For chapter and verse on bedding courses, have a look at:

http://www.pavingexpert.com/layflag3.htm#bornb

For general on flags:

http://www.pavingexpert.com/layflag1.htm


--
Cheers,

John.

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