Dave wrote:

Grunff wrote:

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?!




Ideally you need a wacker to compact it. They are quite good fun to
use. Having said that, this is a very small section of floor, and I
suspect a good bit of jumping up and down might be enough.

The reason for doing this is that if you don't compact it
sufficiently, there's a chance of future settlement, which could cause
your 1x1.7m slab to move relative to its surroundings.


I have a similar question to the OP

I want to put an 8 by 12 foot shed on an old greenhouse base. I intend
throwing all the various bricks and rubble in the middle and topping it
off with hard core.

Without tamping it down, will I have any serious settlement problems?

No. I'd mix in some sand and gravel as well though, so its fairly solid
and there aren't any air pockets.

I threw down a load of MOT type one crush'n'go stuff, and where we havbe
driven cars over it it's now like solid concrete, but where we haven't,
it hasn't settlesd down much at all. Ive laid concrete and stoine over
bits of it no probs.

The whacker made eff all difference frankly. What really works is 30 ton
lorrys driving over it. THATS whacking!



Dave