Sawdust in a wall (!)

[GMM]

Trying to sort the floor in the living room and found the recesses at each = side of the chimney breast, which always seemed pretty shallow, are actuall= y false walls with a load of sawdust packed behind it. Of course, when the= relevant bits of floor came out, so did the sawdust.

It all looks pretty original (Victorian), but might be a later (certainly n= ot recent) addition. The wall in question is a party wall with the house n= ext door. Looks like it might be a single skin.

Does anyone have any idea what the function of the sawdust is? I'm guessin= g some kind of rudimentary insulation for either heat or sound.

With nobody living in the house next door since we arrived, it's not possib= le to know what the sound transmission is like (if that's what it's for), s= o hard to tell whether it might be a real issue. I'm rather assuming that = it would be possible to strip the false walls out and rebuild to a similar = line in plasterboard (sounds more messy than difficult), including a 'sawdu= st substitute' as necessary. If I have to though, it would be best to do t= his sooner rather than later as the next move (once the floor is in) would = be to decorate, carpet etc.

[Frank Erskine]

of the chimney breast, which always seemed pretty shallow, are actually false walls with a load of sawdust packed behind it. Of course, when the relevant bits of floor came out, so did the sawdust.

recent) addition. The wall in question is a party wall with the house next door. Looks like it might be a single skin.

some kind of rudimentary insulation for either heat or sound.

to know what the sound transmission is like (if that's what it's for), so hard to tell whether it might be a real issue. I'm rather assuming that it would be possible to strip the false walls out and rebuild to a similar line in plasterboard (sounds more messy than difficult), including a 'sawdust substitute' as necessary. If I have to though, it would be best to do this sooner rather than later as the next move (once the floor is in) would be to decorate, carpet etc.

Are you sure it _is_ sawdust, rather than, say, vermiculite?

[Phil L]

What is the construction of the false wall? - lath and plaster? I've worked in hundreds of Victorian houses and I've never seen or heard of anything like sawdust to be used in this way, even the Victorians knew about the risks from fire and rodents

It's easy to find out, simply measure the distance outside between yours and next door's windows, half it and then measure the inside recess, if it's a single skin, the difference will be 2 inches

If it is/was for soundproofing, you'd achieve better results with 75mm of rockwool plasterboarded over and skimmed

[The Natural Philosopher]

side of the chimney breast, which always seemed pretty shallow, are actually false walls with a load of sawdust packed behind it. Of course, when the relevant bits of floor came out, so did the sawdust.

recent) addition. The wall in question is a party wall with the house next door. Looks like it might be a single skin.

Woodworm excreta?

Something the bastard whobuilt it just threw in there because it was a place to throw stuff.

I am fairly sure the brickie lefts some turds in my chimney construction.

And the cartons from his sandwiches.

I left a whole bottle of white glue inside a wall once.

I'm guessing some kind of rudimentary insulation for either heat or sound.

to know what the sound transmission is like (if that's what it's for), so hard to tell whether it might be a real issue. I'm rather assuming that it would be possible to strip the false walls out and rebuild to a similar line in plasterboard (sounds more messy than difficult), including a 'sawdust substitute' as necessary. If I have to though, it would be best to do this sooner rather than later as the next move (once the floor is in) would be to decorate, carpet etc.

[GMM]

t each side of the chimney breast, which always seemed pretty shallow, are = actually false walls with a load of sawdust packed behind it. Of course, w= hen the relevant bits of floor came out, so did the sawdust.

ainly not recent) addition. The wall in question is a party wall with the = house next door. Looks like it might be a single skin.

I wouldn't want to meet a woodworm who could produce all that in a dark all= ey! Literally sacks of the stuff.....

not possible to know what the sound transmission is like (if that's wh= at it's for), so hard to tell whether it might be a real issue. I'= m rather assuming that it would be possible to strip the false walls out an= d rebuild to a similar line in plasterboard (sounds more messy than difficu= lt), including a 'sawdust substitute' as necessary. If I have to t= hough, it would be best to do this sooner rather than later as the next mov= e (once the floor is in) would be to decorate, carpet etc.

[GMM]

each side of the chimney breast, which always seemed pretty shallow, are a= ctually false walls with a load of sawdust packed behind it. Of course, wh= en the relevant bits of floor came out, so did the sawdust.

inly not recent) addition. The wall in question is a party wall with the h= ouse next door. Looks like it might be a single skin.

;m guessing some kind of rudimentary insulation for either heat or sound.

not possible to know what the sound transmission is like (if that's wha= t it's for), so hard to tell whether it might be a real issue. I'm= rather assuming that it would be possible to strip the false walls out and= rebuild to a similar line in plasterboard (sounds more messy than difficul= t), including a 'sawdust substitute' as necessary. If I have to th= ough, it would be best to do this sooner rather than later as the next move= (once the floor is in) would be to decorate, carpet etc.

Definitely sawdust - I don't think there's any doubt about that, even thoug= h vermiculite would make more sense.

[Bill]

I know of a commercial building that has a UHF repeater base inside a wall! It was put in a handy alcove for the builders use during construction and when we came to take it out they had blocked it up...

[Owain]

I knew someone who left a transistor radio in a wall.

It kept going to a surprisingly long time and people joked the house was haunted.

Owain

[GMM]

Update - I had another look at it this morning in the light and found the w= all behind this partition is plastered, so presumably the original. I had = thought this must be original as the coving has been continued, but maybe t= hey just made a decent job of it in those days.

A bit of a dilemma just now in terms of what to do, though I'm tempted to g= o with the advice of 'just forget it and see what happens' that my builder = matey recommends. Think I'll be getting rid of the sawdust before laying t= he floor boards though as I don't fancy having that in the void, waiting to= catch fire or make mouse nests.