Structural Hearth Material?

[cjr7]

Have removed the back fill and lime throat from a potentially original ground floor 1910 cast iron fireplace.

Also started removing parts of the rear hearth that were loose or easily broken off by hand.

There's a strange low density material that makes up the rear hearth, seems almost crystalline and porous - any ideas what it is?

A bit of research has lead me to be concerned that it might be old school Vermiculite and therefore may contain asbestos, can anyone shed any light on my concerns?

Here's an image of the rear hearth from above, you can see the rear wall at the top of the image and the tiled superficial hearth at the bottom.

Here is a lump of the material that I am unsure about, it's possible to snap portions of it with your hands.

Many thanks for your help,

Chris

 

[kazuya]

i cant see the pictures but if it does contain asbestos you need to stop disturbing it as your releasing the asbestos fibers into the air and breathing them in.

 

[cjr7]

Thanks for your comments kazuya.

The images aren't showing on my phone now either, I originally posted on the Mac so not sure if there's a formatting issue?

As a precaution, I have stopped work, damped down the area, covered the fireplace with a sheet and shut and blocked the door as much as possible.

I intend to send a sample for asbestos testing but thought there might be someone on here who has experience of fireplaces built at the same time in north London who could put me at ease?

Many thanks

 

[kazuya]

i not sure i know what vermiculite with asbestos looks like, ive obviously just used the newer asbestos free stuff which we would mix with dry cement and pack it into the space behind the fire back, so unless it looks significantly different i wouldn't like to to a guess from a photo anyway.

 

[^woody^]

The images are not visible

Typically, asbestos products were made in the factory not poured in concrete on site.

If it's a pre-formed board of any kind, then yes it may contain asbestos

 

[cjr7]

Just thought I'd post an update.

The images in my original post are showing as I view this page on my phone now.

I sent a sample of the material to an asbestos testing laboratory. They confirmed that the sample is negative for asbestos. So that's good news.

With regards to repairing the pieces of the rear hearth that I've removed, is it advised to use some sort of vermiculite cement mix? I have no intention of using it for a fire but I'm open to the idea of 'doing the right thing' in case.

Many thanks for your responses so far.

 

[chappers]

If you are intending replacing it, just needs to be of non-combustable material standard concrete will be fine