On Nov 30, 6:27 pm, (Andrew Gabriel)
wrote:
In article ,
writes:

Tony says: "If they are breeze block and not the soft Durox blocks you
should be Ok"

Just to clearify. The blocks in question are areated...I can't think
of anything weaker than this stuff.
I've bought them from a local B&Q store....
Maybe I'll have to check my terminology better next time, but I think
my concerns were justified.

They're probably concrete thermal blocks.
Breeze blocks were only used for a few years around 1930s.
Clinker blocks were used up to around 1970 and concrete thermal
blocks since then.

I have seen instructions on drilling concrete thermal blocks on
the manufacturers' websites. Contrary to what one might imagine,
you should drill them with HSS drill bits with no hammer action,
and not masonary drills. Aim to make a clean parallel-sided
cylindrical hole. When screwing into a plug, I lubricate the
screw thread to reduce the twisting force on the plug and
reduce the chance of it turning in the hole and wrecking the
grip.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Thanks Andrew, that's very valuable information.
There is more than just a block apparently...the blocks in question
are made by Celcon and the type is called Solar (not 100% sure).
Just checked their website...got to download some brochures.