Unknown building material in partition wall

[davidji]

The partition walls in my flat seem to be solid. The material is about 3 inches thick, black, and quite soft. It produces a fine dust when drilled - not unlike plaster. It can't be very heavy - its supported by floor joists.

Does anyone know what it is? Will I have to pay someone £100 pounds to find out if its got asbestos in it?

 

[roughcaster]

Hi,
Breeze blocks??

Roughcaster.

 

[JohnD]

Is the building more than 40 years old?

 

[davidji]

I don't think they are breeze blocks - they aren't load bearing, the walls aren't very thick, etc. I guess they might be cinder blocks though - I found cinder blocks by searching for breeze blocks on Wikipedia.

Its about 40 years old - I don't know exactly.

 

[davidji]

Actually now I've read the whole page, it seems like the terms 'cinder block' and 'breeze block' are somewhat interchangeable.

 

[roughcaster]

Hi David,
If I remember correctly,breeze blocks were made from crushed coke, a by-product of coal.It might be a different process nowadays. The word "coke" sadly has a different meaning nowadays as well.

Roughcaster.

 

[davidji]

Yes. But now, the term breeze block is frequently used to mean those concrete blocks with holes in them - so thats what I found when I went looking for them.

I'm pretty sure I have the crushed coke variety, because it explains why my stud detector was so confused. It indicated there were wires everywhere in the wall. Its because the coke conducts electricity somewhat.

 

[davidji]

Anyway, thanks, I've described this material to several building 'experts' including my local council building inspector, and none of them could tell me what it was .

 

[roughcaster]

That's the beauty of the forum.

Roughcaster.

 

[Nige F]

Yes. But now, the term breeze block is frequently used to mean those concrete blocks with holes in them - so thats what I found when I went looking for them.

I'm pretty sure I have the crushed coke variety, because it explains why my stud detector was so confused. It indicated there were wires everywhere in the wall. Its because the coke conducts electricity somewhat.

er, no coke is the remains of coal that used to be heated to make gas before the N.Sea reserves were discovered..and contains metallic minerals like iron pyrites..your Build control lot are kids.....they probably sacked anyone over 50 who`d know what coke was If your wall was conducting electricity, you`d know about it

 

[davidji]

er, no coke is the remains of coal that used to be heated to make gas before the N.Sea reserves were discovered..and contains metallic minerals like iron pyrites..your Build control lot are kids.....they probably sacked anyone over 50 who`d know what coke was If your wall was conducting electricity, you`d know about it

I'm not sure what you are disagreeing with. 'Breeze' is waste ash from power stations. So 'Breeze blocks' were originally waste ash from power stations mixed with cement. Cinder blocks (what I think mine are) are made from cole cinders and cement. Coal cinders really are conductive. The wall may not be conductive, but the instrument just checks for anything that interferes with a magnetic field - so lots of small conducting lumps of cinder set it off. Apparently it confuses damp meters too.

 

[Steve]

ITS THERMALITE!!!!!!

Ruddy useless for fixing stuff to. Make a big hole, fill it with 2-part chemical, and insert wall plug before it sets I tried fixing sockets to it once, got so far into the brick and darent go any further in case I came out the other side. Ended up skimming the wall to level (this was being done anyway though) I glued the metal backboxes into their holes. The only way with this stuff.