Hi

I've just demolished a first floor partition wall constructed with
thermalite blocks. While I was cursing it, it dawned on me it might
not be such a bad idea after all. Is renovation-stress sending me
bonkers, or are there any situations where you can build a block wall
of a wooden floor?

I must be going bonkers...

Regards

T.

On 3 May, 17:40, Tony Bryer wrote:
On 3 May 2007 08:32:27 -0700 wrote :

I've just demolished a first floor partition wall constructed with
thermalite blocks. While I was cursing it, it dawned on me it might
not be such a bad idea after all. Is renovation-stress sending me
bonkers, or are there any situations where you can build a block wall
of a wooden floor?

No it's not uncommon. The floor joists should be strong enough and stiff
enough to support the wall. The joists will deflect as the partition is
being built so then the only deflection after the mortar has set will be
down to the usual occupancy loads.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

I suspect these days a BCO would require a double joist under such a
wall, since they can even fuss about this for a stud wall. Interesting
though, since with blocks the whole thing is perhaps tied together
more due to the mortar etc. I have upstairs walls in my house that are
cinder blocks over floorboards, at right angles to the joists, but
they are a short distance from the brick partitions downstairs. The
only exception is a brick spine wall up the middle of the house that
also helps to support the roof purlins via a V-shaped arrangement. I
hope this spine wall will be able to support a structural floor in the
loft in the future, avoiding the need to big steels.
Simon.

On 3 May 2007 08:32:27 -0700 wrote :
I've just demolished a first floor partition wall constructed with
thermalite blocks. While I was cursing it, it dawned on me it might
not be such a bad idea after all. Is renovation-stress sending me
bonkers, or are there any situations where you can build a block wall
of a wooden floor?

No it's not uncommon. The floor joists should be strong enough and stiff
enough to support the wall. The joists will deflect as the partition is
being built so then the only deflection after the mortar has set will be
down to the usual occupancy loads.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

wrote:

I've just demolished a first floor partition wall constructed with
thermalite blocks. While I was cursing it, it dawned on me it might
not be such a bad idea after all. Is renovation-stress sending me
bonkers, or are there any situations where you can build a block wall
of a wooden floor?

I must be going bonkers...

na, it happens often enough. Best obviously when running perpendicular
to the joists! (can be done parallel if you double up the joist
instead). Having said that you often see places where it is parallel to
the joists and not even over them - sat on the floor between a pair of
joists.

--
Cheers,

John.

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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 4 May, 01:05, John Rumm wrote:
wrote:
I've just demolished a first floor partition wall constructed with
thermalite blocks. While I was cursing it, it dawned on me it might
not be such a bad idea after all. Is renovation-stress sending me
bonkers, or are there any situations where you can build a block wall
of a wooden floor?

I must be going bonkers...

na, it happens often enough. Best obviously when running perpendicular
to the joists! (can be done parallel if you double up the joist
instead). Having said that you often see places where it is parallel to
the joists and not even over them - sat on the floor between a pair of
joists.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

One thing this makes you think about - how much of a house is based on
wood - even a block-built house. In a bad fire, tons of block built on
upstairs rafters could come crashing down, causing far more danger
than with stud walls. I remember someone saying that an American they
knew was scared of our brick houses "in case it collapses on top of
me". I guess they came from a earthquake zone !
Simon.

On Fri, 04 May 2007 01:05:37 +0100, John Rumm
wrote:

wrote:

I've just demolished a first floor partition wall constructed with
thermalite blocks. While I was cursing it, it dawned on me it might
not be such a bad idea after all. Is renovation-stress sending me
bonkers, or are there any situations where you can build a block wall
of a wooden floor?

I must be going bonkers...

na, it happens often enough. Best obviously when running perpendicular
to the joists! (can be done parallel if you double up the joist
instead). Having said that you often see places where it is parallel to
the joists and not even over them - sat on the floor between a pair of
joists.

My bathroom wall is made this way. It's a bit of a pain since some of
the floorboards need replacing!

M

Mark wrote:

na, it happens often enough. Best obviously when running perpendicular
to the joists! (can be done parallel if you double up the joist
instead). Having said that you often see places where it is parallel to
the joists and not even over them - sat on the floor between a pair of
joists.

My bathroom wall is made this way. It's a bit of a pain since some of
the floorboards need replacing!

Just don't do them all at once! ;-)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 4 May 2007 03:04:41 -0700 Sm_jamieson wrote :
One thing this makes you think about - how much of a house is based on
wood - even a block-built house. In a bad fire, tons of block built on
upstairs rafters could come crashing down, causing far more danger
than with stud walls

In a fire, timber joists are a far better bet than steel beams, and the
joists are protected by a plaster[board] ceiling.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

On Fri, 04 May 2007 12:26:33 GMT, a particular chimpanzee, Tony Bryer
randomly hit the keyboard and produced:

In a fire, timber joists are a far better bet than steel beams, and the
joists are protected by a plaster[board] ceiling.

Except when the joists are TJI joists, and except when the
plasterboard ceiling has holes dotted in it for downlighters! Like a
small (show) house fire recently that burnt through the webs of the
joists, leaving the floor deflected by about 200mm and completely
unsupported. If it had been occupied, it's probable anyone up there,
including firefighters, would have come through the floor.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"

On Sun, 06 May 2007 12:31:52 +0100 Hugo Nebula wrote :
Except when the joists are TJI joists, and except when the
plasterboard ceiling has holes dotted in it for downlighters! Like a
small (show) house fire recently that burnt through the webs of the
joists, leaving the floor deflected by about 200mm and completely
unsupported. If it had been occupied, it's probable anyone up there,
including firefighters, would have come through the floor.

What I find more than a little worrying is the thought of this situation
occurring when the floor separates two flats. If you are in the upper flat
your safety may be fatally compromised without you realising it.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

On Sun, 06 May 2007 13:15:31 GMT, Tony Bryer
mused:

On Sun, 06 May 2007 12:31:52 +0100 Hugo Nebula wrote :
Except when the joists are TJI joists, and except when the
plasterboard ceiling has holes dotted in it for downlighters! Like a
small (show) house fire recently that burnt through the webs of the
joists, leaving the floor deflected by about 200mm and completely
unsupported. If it had been occupied, it's probable anyone up there,
including firefighters, would have come through the floor.

What I find more than a little worrying is the thought of this situation
occurring when the floor separates two flats. If you are in the upper flat
your safety may be fatally compromised without you realising it.

The floors between 2 flats should be of a better fire resistant
construction than between 2 levels in a domestic multi storey property
though.
--
Regards,
Stuart.

On Sun, 06 May 2007 21:24:54 GMT, Tony Bryer
mused:

On Sun, 06 May 2007 14:48:05 +0100 Lurch wrote :
The floors between 2 flats should be of a better fire resistant
construction than between 2 levels in a domestic multi storey property
though.

I'm not up to date with current requirements, but it used to be full 1/2
hour for 2-storey (2 layers PB) and one hour for 3-storey which IIRC was 2
x 12mm PB. No protection against holesaw man and his concealed
downlighters.

Nowadays fire hoods should be fitted and all fire breaks should be
maintained through walls and ceilings. Most ignore that though.
--
Regards,
Stuart.

On Sun, 06 May 2007 14:48:05 +0100 Lurch wrote :
The floors between 2 flats should be of a better fire resistant
construction than between 2 levels in a domestic multi storey property
though.

I'm not up to date with current requirements, but it used to be full 1/2
hour for 2-storey (2 layers PB) and one hour for 3-storey which IIRC was 2
x 12mm PB. No protection against holesaw man and his concealed
downlighters.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

Yeah, makes you wondered about all those engineered joist. Good idea structurally and very lightweight compared to their predecessors, but give them a bit of fire and away they go!