Burning under hearth ??

[slowlybutsurely]

Old property has a couple of fireplaces with sunken hearths. I want to have waxed floorboards so at the very least I needed to level it.

See pictures showing sunken level - approx 2cm at worst point.



So I ripped it up - the tiles, the cracked slab, ...

And found the cause of the sinking problem was that the joist and several of wood boards were burnt through (see pics)



These were the wooden board that supported the cement slab (that cracked later).

So my question ... WTF,, there was fire under the hearth ????


Thanks
Chris


ps: and now I'm like this. Ready to rebuild )))

 

[ree]

The Great Fire of London was caused by tiny embers slipping through cracks in the stone hearth.

The ground floor chimney breast front hearth (your hearth) should be made from stone or concrete supported on a surrounding fender wall. Typically the fender wall is brick with an in-fill of soil.

The hearth should never be laid on wood - over wood - or supported by wood.

However, many hearths, like yours, were supported on wood - or wood floor boards were extended almost into the fireplace opening.

What you have done by way of a sand and cement infill is fine but was it laid on a membrane to prevent damp from coming up?
I presume its finished just below FFL to allow for the new patch of wood flooring?

There are other concerns ref. venting and sweeping flues - FWIW: why not research some of my previous posts on these subjects; you might find them useful?

Note: i've worked on c/breasts & flues with similar or far worse charred and smoked woodwork that should have burned the house down but didn't. To see what dangerous rubbish builders are capable of google: victorian hearth construction