Unidentified material in my floor

[alwd000]

Hello

Please help!

I live in the first floor flat of a Victorian conversion. My freeholder and neighbour lives below on the ground floor. The freeholder started to do some renovations and discovered that my kitchen floor/his ceiling had had a material substance poured between the joists. The slab is approx 2mx3m and looks like some sort of rouble like cement. He then got a structural engineer to do drawing for a steel to be erected to support the ceiling. With out any tests he claims the material is concrete.

I found a neighbour on my street who lives on the first floor like myself and has exactly the same material in exactly the same area of his flat.
He believes the material is generations old, it looks like concrete but is light in weight and breaks up very easily. He thought it was an old fashioned material to stop infestations/rodents etc.

My question is does anyone no what the material is called or what it could be for? Would it have needed to have an RSJ installed?

It's a shame the structural engineer didn't do a proper report on the substance.

I would greatly appreciate any help
Many thanks

 

[88v8]

Hello and welcome.

Those look like new joists.
Is the ceiling sagging under the weight of this material, or is it OK?

I would think that the material, whatever it is, is there for soundproofing &/or fire resistance. Its presence therefore suggests that the conversion was done properly. Unless there is some particular reason, I would not worry about it. However, where it has been damaged, I would reinstate it.

Which comes back to your question... what is it...
Are you sure it's poured? It could be a form of gypsum, which is a lightweight sound insulator.
Here:
http://sweets.construction.com/swts_content_files/1558/651732.pdf

If the freeholder contacts the Council Building Control dept, he may be able to trace plans which identify the material and its purpose. However, if the conversion was done without permission, that could open a can of worms.

As this is a general building question, you may also get information here:
http://www.diynot.com/forums/viewforum.php?f=13
Ivor

 

[Keith Bowman]

Looks to me like a case for the Henry Ford approach - "If it ain't broke, don't fix it"!

Is there any evidence that it is doing any harm? Is the ceiling actually sagging? Personally (me being a person with no qualifications who always looks for the simple solution!) I would rely on the evidence of my own eyes - the neighbour who appears actually to have investigated it says it is lightweight.

But I'm sure some real expert will be along soon.

 

[Lime]

A lightweight concrete?
Probably micafil Vermiculite or other trade name.
Used for sound deadening, fire resistance etc.

PDF:
http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=1&cad=rja&uact=8&ved=0CDwQFjAA&url=http%3A%2F%2Fwww.dupreminerals.com%2Fdownloads%2Fapplications%2Fguide-lightweightconcrete.pdf&ei=6e5pU9-NO4LB0gW844D4AQ&usg=AFQjCNGMxPD8EEok_KoEC6_bwwNTIkwFiw&bvm=bv.66111022,d.d2k


http://www.matweb.com/search/datasheettext.aspx?matguid=c2790d2f01704f99a38f47134282adce

 

[CliffordPope]

I've sometimes encountered an old-fashioned version of that. It seems to be lightweight aerated coke clinker, mixed with lime.
Definitely poured - it takes up all the impressions of laths, wood grain, nails, etc.

 

[dandrew]

When I lived in a tenement in Glasgow the space between the joists was filled with old fire ashes, it was the period sound-proofing of the era (1850's), and I have seen it mentioned in old joinery books.

David

 

[alwd000]

Thank you all very much, much appreciated.
alwd000