(Sort of) sleeper wall problem: any ideas?
 

10-12 years ago I packed out the gaps which had developed between the
sleeper walls on top of the concrete float and the joists supporting our
timber kitchen floor (1920s semi, North London). The floor had become bouncy
again and with new kitchen units en route and some electrics needing
attention, it was time today to rip it up again. I found some small gaps
from extra settlement over the intervening years, but no more than you'd
expect. But the real problem appears to be around the boiler alcove in the
middle of one wall - presumably once a fireplace. This is an area I didn't
even look at when packing the joists before. There seems to be a brick
sleeper-type wall built out around the former fireplace area. The middle of
it seems to be full of old builders' rubble into which I can poke a stick
for a long way but there is a concrete shelf above - thankfully sound as far
as I can see - supporting the boiler. As you can see from this pic:

http://www.justigator.pwp.blueyonder.../DSC00681a.jpg

three of the joists are supposed to rest on the wall top but the wall has
settled and a gap has opened up (there was also originally a length of joist
timber along the concrete edge at right angles to the joists which was
completely rotten and providing no support). To judge from the amount of
curve in the floorboards, the joists have dropped some 20mm and are now not
properly supported at their ends - although they are at the sleeper wall in
front (packing shown is undisturbed from last time). It may not be clear
from the photo but the top of the problem wall has a pronounced lean towards
the camera - enough to make me unwilling to just put more packing under and
seal up again, for fear of it just collapsing under the extra weight.

The local BCO won't visit to advise and it's next to impossible to get a
builder round here these days for this sort of thing. So I'm planning to
build a new sort of mega-sleeper wall between the one in the foreground and
the problem wall, filling in the whole intervening area to try to both
provide support for the floor and prevent any further sliding out forwards
of the fireplace support wall. I don't forsee any problem with ventilation -
there is plenty down there and I will leave gaps.

Does anyone have any tips or suggestions please? TIA.


--
RRH

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(Sort of) sleeper wall problem: any ideas?
 

"rrh" wrote in message
...
10-12 years ago I packed out the gaps which had developed between the
sleeper walls on top of the concrete float and the joists supporting our
timber kitchen floor (1920s semi, North London). The floor had become
bouncy
again and with new kitchen units en route and some electrics needing
attention, it was time today to rip it up again. I found some small gaps
from extra settlement over the intervening years, but no more than you'd
expect. But the real problem appears to be around the boiler alcove in the
middle of one wall - presumably once a fireplace. This is an area I didn't
even look at when packing the joists before. There seems to be a brick
sleeper-type wall built out around the former fireplace area. The middle
of
it seems to be full of old builders' rubble into which I can poke a stick
for a long way but there is a concrete shelf above - thankfully sound as
far
as I can see - supporting the boiler. As you can see from this pic:

http://www.justigator.pwp.blueyonder.../DSC00681a.jpg

three of the joists are supposed to rest on the wall top but the wall has
settled and a gap has opened up (there was also originally a length of
joist
timber along the concrete edge at right angles to the joists which was
completely rotten and providing no support). To judge from the amount of
curve in the floorboards, the joists have dropped some 20mm and are now
not
properly supported at their ends - although they are at the sleeper wall
in
front (packing shown is undisturbed from last time). It may not be clear
from the photo but the top of the problem wall has a pronounced lean
towards
the camera - enough to make me unwilling to just put more packing under
and
seal up again, for fear of it just collapsing under the extra weight.


I'm a bit confussed, but can't you just pack the 20mm with broken slate
tiles? I raise part of our floor that way. Jack up the joist with a car
jack, put in the slate shimm and relax the jack.

Scott

(Sort of) sleeper wall problem: any ideas?
 

I'm a bit confussed, but can't you just pack the 20mm with broken slate
tiles? I raise part of our floor that way. Jack up the joist with a car
jack, put in the slate shimm and relax the jack.

Scott


Sure I could, but the point is that the wall around the fireplace area
hasn't just settled downwards a bit, it has developed a noticeable lean out
of vertical. If I just pack onto the top of it, I'm worried that it will
collapse (at some future point when the floor is well and truly covered with
expensive tiles...).

(Sort of) sleeper wall problem: any ideas?
 

"rrh" wrote in message
...
I'm a bit confussed, but can't you just pack the 20mm with broken slate
tiles? I raise part of our floor that way. Jack up the joist with a
car
jack, put in the slate shimm and relax the jack.

Scott


Sure I could, but the point is that the wall around the fireplace area
hasn't just settled downwards a bit, it has developed a noticeable lean
out
of vertical. If I just pack onto the top of it, I'm worried that it will
collapse (at some future point when the floor is well and truly covered
with
expensive tiles...).

Ahh, now I have re-read your post and looked at the picture it has all
become clear. I would build a wall next to it as you suggest ie on the
side away from the camera. Use a few large breeze blocks so that the job is
quick and cheap - remember to put in a DPC. You don't have to be neat on
with the cement either, and it might be worth treating the wood too while
you're there.

Scott

(Sort of) sleeper wall problem: any ideas?
 

Scott Mills wrote
Ahh, now I have re-read your post and looked at the picture it has all
become clear. I would build a wall next to it as you suggest ie on the
side away from the camera. Use a few large breeze blocks so that the job is
quick and cheap - remember to put in a DPC. You don't have to be neat on
with the cement either, and it might be worth treating the wood too while
you're there.

Scott

OK, but remember the settlement is likely to be due to shrinking clay (North
London) so if you build it straight off the oversite it will probably settle
(relative to the main house walls) again in time. Ideally it needs a decent
foundation, to the same depth as the main walls. Also, make sure you leave some
holes in the wall to allow air to circulate.

Peter

(Sort of) sleeper wall problem: any ideas?
 

OK, but remember the settlement is likely to be due to shrinking clay
(North
London) so if you build it straight off the oversite it will probably
settle
(relative to the main house walls) again in time. Ideally it needs a
decent
foundation, to the same depth as the main walls. Also, make sure you
leave some
holes in the wall to allow air to circulate.

Peter

I thought this method of house construction put everything (from outer walls
inwards) onto one large concrete slab, rather than have the main walls on
separate foundations? That's certainly what it looks like as far as I can
see. Either way some further settlement seems inevitable but at the current
rate of less than 5mm per decade I think I can live with it.