Rick wrote:
On Thu, 31 Mar 2005 14:03:54 GMT, Lobster
wrote:


I'm about to start laying a new small section of solid floor (approx 1m
x 1.7m) - first time I've ever done this. Think I've extracted from the
uk.d-i-y archives all I need to know, but could someone explain about
requirement for compacting hardcore prior to laying the concrete? I
have excavated about to about 15" below the final surface (it's earth
now), and was going to chuck in 6" hardcore now. Am I supposed to sort
of jump up and down on the hardcore a bit before I blind it with sand?!

Thanks for all the replies. I'd love to play with a 'wacker' but looks
a bit pricey and maybe a bit overkill for my small application. I think
given that the area concerned is going to be at the end of an L-shaped
utility room, most of it will be under units, so shouldn't get too much
loading. Reckon if I use a hand tamper; and maybe screw some rods into
the side of the existing, abutting slab as reinforcement before pouring
the new mix, that would dissuade anything from settling?

9 inches of concerete sounds like quite a bit for a floor, unless you
are building on it.

See above. The deal is that I have an existing, very old, concrete slab
which I'm adding to: BCO wants a DPC, 2" kingspan, then 3" screed which
will bring it all up to the level of the adjacent kitchen. Before that
I'm extending the slab by this extra 1m, ie preparing a new slab to come
up to the level of the old one. So that will be 6" hardcore followed by
4" concrete (then later the DPC, kingspan etc... complicated to explain!)

David