In article ,
descds wrote:

Mmmmmmmmmmm yes i see you point. I have little chose but to use them
at the moment for the lack of having anything else. But i guess it
would be the same if they were mortar'd and at least they'll be easier
to take down if and when they do crack and crumble ...

Yes.

I'm uncertain if these are modern breeze blocks or concrete blocks.
They are solid mass grey bricks that i always associated with breeze
blocks but are quite heavy (carrying two is about my lot and that's
not pleasant). Hopefully they will do the job for a number of years as
free is always about the price i enjoy paying for hard features of the
garden Having said that i have just spend yet another £100 + on
plants (God i'm addicted ) which brings the total way over £250 this
year alone ((((( I need help ...

The modern ones I am referring to can be cut with a kitchen knife
(though not easily or without blunting the knife) and absorb water
like sponges. The older ones were much harder, sometimes (but not
always) looked as if they were made of concrete Rice Krispies, and
usually (but not always) absorbed water readily (if not like sponges).
In both cases, they can be split dead easily using a hammer and
bolster.

Concrete blocks will resist even a cold chisel, will rarely absorb
water and (as you say) are heavier. But they are rarely made in
large sizes, and you would have difficulty carrying two if they were.


Regards,
Nick Maclaren.