I've had to do some exploratory & other surgery in the kitchen ceiling
(also bathroom floor) as a result of a loose connection in an old
junction box (kitchen & bathroom lights went off sometimes but came
back on if you stepped on the right area on the bathroom floor).
That's all fine now (Wago box; new ceiling light; big mess cleaned
up), but I wonder about the weird situation I found in the
ceiling/floor.

= bathroom floor
- kitchen ceiling
X joist


================================
XX XX
XX XX XX XX
XX XX XX XX
XX XX
--------------------------------

That's a cross-section. There seem to be two sets of joists: one set
has a gap above & the (lath & plaster) ceiling attached below; the
other has a gap below & the floorboards attached above. I've only
worked in the middle, so I don't know how the ends of the joists are
attached to the walls.

Any explanation for this weird situation?

Thanks,
Adam

On 5/15/2016 9:12 PM, Adam Funk wrote:
I've had to do some exploratory & other surgery in the kitchen ceiling
(also bathroom floor) as a result of a loose connection in an old
junction box (kitchen & bathroom lights went off sometimes but came
back on if you stepped on the right area on the bathroom floor).
That's all fine now (Wago box; new ceiling light; big mess cleaned
up), but I wonder about the weird situation I found in the
ceiling/floor.

= bathroom floor
- kitchen ceiling
X joist


================================
XX XX
XX XX XX XX
XX XX XX XX
XX XX
--------------------------------

That's a cross-section. There seem to be two sets of joists: one set
has a gap above & the (lath & plaster) ceiling attached below; the
other has a gap below & the floorboards attached above. I've only
worked in the middle, so I don't know how the ends of the joists are
attached to the walls.

Any explanation for this weird situation?

Thanks,
Adam


I imagine the extra joists have been added at some time in order to
adjust the level of the bathroom floor. You don't state the age of the
property (other than that with L&P it's presumably well over 50 years
old) but in my 1780's cottage movement in the 2x2 inch oak joists means
some of my floorboard would be all over the place without packing.

On 2016-05-15, newshound wrote:

I imagine the extra joists have been added at some time in order to
adjust the level of the bathroom floor. You don't state the age of the
property (other than that with L&P it's presumably well over 50 years
old) but in my 1780's cottage movement in the 2x2 inch oak joists means
some of my floorboard would be all over the place without packing.

I think the rest of the house is 1910s & the kitchen & bathroom were
added at some point (well over 50 years ago). Next time I get a
chance I'll see if I can "periscope" (torch + phone camera) to see
what's happening at the ends of the joists.

In message , Adam Funk
writes
I've had to do some exploratory & other surgery in the kitchen ceiling
(also bathroom floor) as a result of a loose connection in an old
junction box (kitchen & bathroom lights went off sometimes but came
back on if you stepped on the right area on the bathroom floor).
That's all fine now (Wago box; new ceiling light; big mess cleaned
up), but I wonder about the weird situation I found in the
ceiling/floor.

= bathroom floor
- kitchen ceiling
X joist


================================
XX XX
XX XX XX XX
XX XX XX XX
XX XX
--------------------------------

That's a cross-section. There seem to be two sets of joists: one set
has a gap above & the (lath & plaster) ceiling attached below; the
other has a gap below & the floorboards attached above. I've only
worked in the middle, so I don't know how the ends of the joists are
attached to the walls.

Any explanation for this weird situation?

Your diagram does not display well with my reader.

We had a similar situation where dormers had been added to a bungalow.
The existing loft floor joists were probably 7"x2" and the new floor
joists 9"x2".

It would have been much better if they had bolted the joist pairs
together as loading the new floor tended to ping the plasterboard nails
off the downstairs ceiling.

Also done where there is a load such as a cold water header tank.
--
Tim Lamb

On 2016-05-15, Tim Lamb wrote:

In message , Adam Funk
writes
I've had to do some exploratory & other surgery in the kitchen ceiling
(also bathroom floor) as a result of a loose connection in an old
junction box (kitchen & bathroom lights went off sometimes but came
back on if you stepped on the right area on the bathroom floor).
That's all fine now (Wago box; new ceiling light; big mess cleaned
up), but I wonder about the weird situation I found in the
ceiling/floor.

= bathroom floor
- kitchen ceiling
X joist


================================
XX XX
XX XX XX XX
XX XX XX XX
XX XX
--------------------------------

That's a cross-section. There seem to be two sets of joists: one set
has a gap above & the (lath & plaster) ceiling attached below; the
other has a gap below & the floorboards attached above. I've only
worked in the middle, so I don't know how the ends of the joists are
attached to the walls.

Any explanation for this weird situation?

Your diagram does not display well with my reader.

It's meant for monospace. I forgot to clarify in the text that there
is a gap of 25 to 30 mm between each low joist & the adjacent high
joist --- it's not *too* difficult to snake lighting cable under, up,
& over them, between holes in the kitchen ceiling on opposite sides of
a joist pair.


We had a similar situation where dormers had been added to a bungalow.
The existing loft floor joists were probably 7"x2" and the new floor
joists 9"x2".

It would have been much better if they had bolted the joist pairs
together as loading the new floor tended to ping the plasterboard nails
off the downstairs ceiling.

Also done where there is a load such as a cold water header tank.

AFAICT, the ground floor kitchen & 1st floor bathroom were built at
the same time as one offshot (on a mid-terrace).

I'm reluctant to go back & take more measurements because I'd have to
clean the dust out of the kitchen again!

On 15/05/2016 22:27, Adam Funk wrote:
On 2016-05-15, Tim Lamb wrote:

In message , Adam Funk
writes
I've had to do some exploratory & other surgery in the kitchen ceiling
(also bathroom floor) as a result of a loose connection in an old
junction box (kitchen & bathroom lights went off sometimes but came
back on if you stepped on the right area on the bathroom floor).
That's all fine now (Wago box; new ceiling light; big mess cleaned
up), but I wonder about the weird situation I found in the
ceiling/floor.

= bathroom floor
- kitchen ceiling
X joist


================================
XX XX
XX XX XX XX
XX XX XX XX
XX XX
--------------------------------

That's a cross-section. There seem to be two sets of joists: one set
has a gap above & the (lath & plaster) ceiling attached below; the
other has a gap below & the floorboards attached above. I've only
worked in the middle, so I don't know how the ends of the joists are
attached to the walls.

Any explanation for this weird situation?

Your diagram does not display well with my reader.

It's meant for monospace. I forgot to clarify in the text that there
is a gap of 25 to 30 mm between each low joist & the adjacent high
joist --- it's not *too* difficult to snake lighting cable under, up,
& over them, between holes in the kitchen ceiling on opposite sides of
a joist pair.


We had a similar situation where dormers had been added to a bungalow.
The existing loft floor joists were probably 7"x2" and the new floor
joists 9"x2".

It would have been much better if they had bolted the joist pairs
together as loading the new floor tended to ping the plasterboard nails
off the downstairs ceiling.

Also done where there is a load such as a cold water header tank.

AFAICT, the ground floor kitchen & 1st floor bathroom were built at
the same time as one offshot (on a mid-terrace).

I'm reluctant to go back & take more measurements because I'd have to
clean the dust out of the kitchen again!

Is it only the bathroom or all upstairs floors? If all, could it be to
decouple the floors and ceilings to reduce noise transmission?

On 2016-05-15, Steve Walker wrote:

On 15/05/2016 22:27, Adam Funk wrote:
On 2016-05-15, Tim Lamb wrote:

We had a similar situation where dormers had been added to a bungalow.
The existing loft floor joists were probably 7"x2" and the new floor
joists 9"x2".

It would have been much better if they had bolted the joist pairs
together as loading the new floor tended to ping the plasterboard nails
off the downstairs ceiling.

Also done where there is a load such as a cold water header tank.

AFAICT, the ground floor kitchen & 1st floor bathroom were built at
the same time as one offshot (on a mid-terrace).

I'm reluctant to go back & take more measurements because I'd have to
clean the dust out of the kitchen again!

Is it only the bathroom or all upstairs floors? If all, could it be to
decouple the floors and ceilings to reduce noise transmission?

It's only in the offshot (bathroom above kitchen). I don't think they
worried about "advanced" things like noise through floors when it was
built.

On 16/05/16 10:39, Adam Funk wrote:
On 2016-05-15, Steve Walker wrote:

On 15/05/2016 22:27, Adam Funk wrote:
On 2016-05-15, Tim Lamb wrote:

We had a similar situation where dormers had been added to a bungalow.
The existing loft floor joists were probably 7"x2" and the new floor
joists 9"x2".

It would have been much better if they had bolted the joist pairs
together as loading the new floor tended to ping the plasterboard nails
off the downstairs ceiling.

Also done where there is a load such as a cold water header tank.

AFAICT, the ground floor kitchen & 1st floor bathroom were built at
the same time as one offshot (on a mid-terrace).

I'm reluctant to go back & take more measurements because I'd have to
clean the dust out of the kitchen again!

Is it only the bathroom or all upstairs floors? If all, could it be to
decouple the floors and ceilings to reduce noise transmission?

It's only in the offshot (bathroom above kitchen). I don't think they
worried about "advanced" things like noise through floors when it was
built.


It looks pretty clear to me. Originally there was no bathroom,. just a
kitchen with a ceiling and possibly a flat roof.

Then the bathroom was added, and the ceiling joists were not at the
right height, and or inadequate. so a new set of joist were laid in to
take the floor

AFAICT, the ground floor kitchen & 1st floor bathroom were built at
the same time as one offshot (on a mid-terrace).

I would say the evidence is against that, personally.
Or it could be that the builder at the time had ordered 6x3 timber, was
under pressure, and realised he needed 7x3, to match the existing house,
and said 'sod that, I'll use two sets of joists instead and 6x3 timber'
or whatever.

BTW WTDF is an 'offshot' bathroom?
One what isn't in video view?




--
All political activity makes complete sense once the proposition that
all government is basically a self-legalising protection racket, is
fully understood.

On Sunday, 15 May 2016 21:15:05 UTC+1, Adam Funk wrote:
I've had to do some exploratory & other surgery in the kitchen ceiling
(also bathroom floor) as a result of a loose connection in an old
junction box (kitchen & bathroom lights went off sometimes but came
back on if you stepped on the right area on the bathroom floor).
That's all fine now (Wago box; new ceiling light; big mess cleaned
up), but I wonder about the weird situation I found in the
ceiling/floor.

= bathroom floor
- kitchen ceiling
X joist


================================
XX XX
XX XX XX XX
XX XX XX XX
XX XX
--------------------------------

That's a cross-section. There seem to be two sets of joists: one set
has a gap above & the (lath & plaster) ceiling attached below; the
other has a gap below & the floorboards attached above. I've only
worked in the middle, so I don't know how the ends of the joists are
attached to the walls.

Any explanation for this weird situation?

Thanks,
Adam

It is likely intended to reduce sound transmission between the rooms.