does this look like pyrite

cuculainn

Just noticed this gold like substance leaching from blockwork. Could anyone tell me if its pyrite? I have added pics

Sundy

Hmm hard to say from the pictures. Whats behind the wall?

Anyway pyrite isnt a problem in concrete blocks as the aggregate is generally not exposed to air. Fill material is where the alleged problems with pyrite arise.

cuculainn

Sundy wrote: »

Hmm hard to say from the pictures. Whats behind the wall?

Anyway pyrite isnt a problem in concrete blocks as the aggregate is generally not exposed to air. Fill material is where the alleged problems with pyrite arise.

Thanks for the reply sundy, the two pics are of internal walls. What exactly do you mean by fill material?

Mellor

Hardcore, Crushed stone, rubble etc used as fill below slabs and foundations

L_Bonn

I see alot of that in very cold weather. It has never been a problem nywhere Ive seen it

tred

cuculainn wrote: »

Thanks for the reply sundy, the two pics are of internal walls. What exactly do you mean by fill material?

when your reading about all these pyrite problems, and cracked walls etc, its not because the morter has pyrite. what was happening was sites were filled with rubble under the foundations. But some of these stuff had pyrite, which is not suitable for this purpose, becase after a period of time it absorbes water, and expands!.

cuculainn

tred wrote: »

when your reading about all these pyrite problems, and cracked walls etc, its not because the morter has pyrite. what was happening was sites were filled with rubble under the foundations. But some of these stuff had pyrite, which is not suitable for this purpose, becase after a period of time it absorbes water, and expands!.

Well that is a relief.......I was a bit concerned when it appeared.

Out of curiosity does anyone know what caused it so??

mrgaa1

when was that wall built? And where in your building is that wall - internal/external?

dathi

its efflorescence the salts in the sand are leaching out harmless

BDSC1964

cuculainn wrote: »

Well that is a relief.......I was a bit concerned when it appeared.

Out of curiosity does anyone know what caused it so??

Cuculainn can you say when the wall was built. Pyrite normally does not show itself for several years. it looks like some contaminant go into the mix. I have seen a case of a house completely wreaked by pyrite in blockwork.

Does it smell. if it has a gypsum or sulphur odour get it checked out by a structural engineer.

cuculainn

Thanks for the reply. The walls were blocked between june and sep of 2010. So about 8 months ago. I haven't noticed a smell but have really gone up close to it!!