Helping a friend at the weekend, and found a roof leak has
caused the wallplate to disintegrate, which I removed with
the vacuum cleaner ;-)

Originally sitting on this was a sodding great compound beam
which runs the length of the house and has a loft extension
built on it. It was floating in mid air with the wall plate
having gone from under it, and has dropped about an inch from
where it originally was. I have for the time being packed
the gap under it with engineering bricks so it can't drop any
further, although before that I got friend to go and walk
around and then jump in the loft extention, and there was
virtually no movement in the beam-end (much less than 1mm).

So the question is, is it worth trying to jack the beam
back up by the inch it's dropped before reinstating the
support under it? The two doors in the loft extention both
jam slightly in the frame, possibly due to this distortion.
I'm guessing the weight might have transferred to some other
part of the structure which might not be so well suited to
take it, although there's nothing else under that beam for
a few metres at least.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

My feeling is you'd have to do it very slowly - perhaps over the course of
a nice cold damp winter.

--
*Do they ever shut up on your planet?

Dave Plowman London SW
To e-mail, change noise into sound.

On Sep 17, 1:04*pm, (Andrew Gabriel)
wrote:
Helping a friend at the weekend, and found a roof leak has
caused the wallplate to disintegrate, which I removed with
the vacuum cleaner ;-)

Originally sitting on this was a sodding great compound beam
which runs the length of the house and has a loft extension
built on it. *It was floating in mid air with the wall plate
having gone from under it, and has dropped about an inch from
where it originally was. I have for the time being packed
the gap under it with engineering bricks so it can't drop any
further, although before that I got friend to go and walk
around and then jump in the loft extention, and there was
virtually no movement in the beam-end (much less than 1mm).

So the question is, is it worth trying to jack the beam
back up by the inch it's dropped before reinstating the
support under it? The two doors in the loft extention both
jam slightly in the frame, possibly due to this distortion.
I'm guessing the weight might have transferred to some other
part of the structure which might not be so well suited to
take it, although there's nothing else under that beam for
a few metres at least.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]


One of these suck it and see jobs.
Jack it up progressively and see what happens round the place as you
do.
Checks the doors, if new cracks appear elsewhere plus whatever else
you can think of. Listen for creaks and cracks.
If work has been done since it sunk (eg plastering) raising it may not
be possible.
You want to have a real good look round for other rot too.

"Andrew Gabriel" wrote in message
...
Helping a friend at the weekend, and found a roof leak has
caused the wallplate to disintegrate, which I removed with
the vacuum cleaner ;-)

Originally sitting on this was a sodding great compound beam
which runs the length of the house and has a loft extension
built on it. It was floating in mid air with the wall plate
having gone from under it, and has dropped about an inch from
where it originally was. I have for the time being packed
the gap under it with engineering bricks so it can't drop any
further, although before that I got friend to go and walk
around and then jump in the loft extention, and there was
virtually no movement in the beam-end (much less than 1mm).

So the question is, is it worth trying to jack the beam
back up by the inch it's dropped before reinstating the
support under it? The two doors in the loft extention both
jam slightly in the frame, possibly due to this distortion.
I'm guessing the weight might have transferred to some other
part of the structure which might not be so well suited to
take it, although there's nothing else under that beam for
a few metres at least.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

I'm no expert, some immediate thoughts. From what you say the compound beam
is in decent order. By compound beam I presume a steel beam of various
sections fabricated to the form required. The cause of the initial problem
obviously needs to be addressed and fixed before, or during, the remedial
works. No doubt the wallplate is compromised beyond what is currently
visible. This would have to be cut back to sound timber. Don't know the
dimensions involved. Would use hydraulic cylinders and suitable
load-spreading packings. Slowly does it but I imagine a matter of days/weeks
rather than months. Check house insurance. Structural engineer?
I would certainly say that it should be raised to original level and made
good. No doubt the beam will settle back given time.

Just my 2d's worth.

Nick

In message , Andrew Gabriel
writes
Helping a friend at the weekend, and found a roof leak has
caused the wallplate to disintegrate, which I removed with
the vacuum cleaner ;-)

Originally sitting on this was a sodding great compound beam
which runs the length of the house and has a loft extension
built on it. It was floating in mid air with the wall plate
having gone from under it, and has dropped about an inch from
where it originally was. I have for the time being packed
the gap under it with engineering bricks so it can't drop any
further, although before that I got friend to go and walk
around and then jump in the loft extention, and there was
virtually no movement in the beam-end (much less than 1mm).

So the question is, is it worth trying to jack the beam
back up by the inch it's dropped before reinstating the
support under it? The two doors in the loft extention both
jam slightly in the frame, possibly due to this distortion.
I'm guessing the weight might have transferred to some other
part of the structure which might not be so well suited to
take it, although there's nothing else under that beam for
a few metres at least.

I have jacked up the loft floor of a Victorian barn with nothing
untoward happening. Raised about 4" with lots of creaks.

The other experience is where I had carefully supported a main floor
beam to allow some bricks to be replaced in a chimney breast. To my
horror, when the job was done, the brickie just dropped the Acrow prop
lowering the beam by about 3/4" onto his top brick. Again no noticeable
effects.


--
Tim Lamb

In article ,
"Nick" wrote:

... Check house insurance. Structural engineer?

You said it. *MUCH* as I admire and respect Andrew's experience and
expertise in the field, I'd recommend paying out for a firm of
structural engineers to have a look at the whole job: this sounds like
"nowt to worry about there old chap!", or .... a potential disaster!
Personally I'd rather have the experts give their views.

John

Another John wrote:
In article ,
"Nick" wrote:

... Check house insurance. Structural engineer?

You said it. *MUCH* as I admire and respect Andrew's experience and
expertise in the field, I'd recommend paying out for a firm of
structural engineers to have a look at the whole job: this sounds like
"nowt to worry about there old chap!", or .... a potential disaster!
Personally I'd rather have the experts give their views.

John

Isn't he just going to say "jack it up and replace the hanger"?

Tim

On Sep 17, 9:56*pm, Another John wrote:
In article ,

*"Nick" wrote:
... Check house insurance. Structural engineer?

You said it. * *MUCH* as I admire and respect Andrew's experience and
expertise in the field, I'd recommend paying out for a firm of
structural engineers to have a look at the whole job: this sounds like
"nowt to worry about there old chap!", or .... a potential disaster!
Personally I'd rather have the experts give their views.

John


Trivial job. Pay out £x00 to get the same advice as he got here?
Bonkers

harry wrote:

On Sep 17, 9:56 pm, Another John wrote:
In article ,

"Nick" wrote:
... Check house insurance. Structural engineer?

You said it. *MUCH* as I admire and respect Andrew's experience and
expertise in the field, I'd recommend paying out for a firm of
structural engineers to have a look at the whole job: this sounds like
"nowt to worry about there old chap!", or .... a potential disaster!
Personally I'd rather have the experts give their views.

John


Trivial job. Pay out £x00 to get the same advice as he got here?
Bonkers

We don't have liability insurance...


--
Tim Watts

"Andrew Gabriel" wrote in message
...
Helping a friend at the weekend, and found a roof leak has
caused the wallplate to disintegrate, which I removed with
the vacuum cleaner ;-)

Originally sitting on this was a sodding great compound beam
which runs the length of the house and has a loft extension
built on it. It was floating in mid air with the wall plate
having gone from under it, and has dropped about an inch from
where it originally was. I have for the time being packed
the gap under it with engineering bricks so it can't drop any
further, although before that I got friend to go and walk
around and then jump in the loft extention, and there was
virtually no movement in the beam-end (much less than 1mm).

So the question is, is it worth trying to jack the beam
back up by the inch it's dropped before reinstating the
support under it?

If this in a loft, what are you jacking against ?
If the foot of the jack is on roof timbers - or even
on a metal plate spread across more than one then in
atempting to jack up the beam all you may succeed in
doing, is stressing whatever the jack is based on.

IANASE but this would presumably depend on how much
load is bearing down on the beam - i.e load that
would have to be lifted to get the beam level, as against
how much load, whatever you rest the jack on, is designed
to support. The point being that roof timbers form
an integrated structure whose strength comes from the way
the structural members are joined using tension
and compression and to end along the grain, but nor
necessarily bending strength across the grain bewteen
the ends as here.

You don't say how many floors this building is.
But I'd imaging whatever jacking point you use will
probably need support from below from ground level up.
This would involve removing sections of floorboards
and ceilings in each room and bracing the structiural
woodwork beween floors and ceiling on each floor
with an acrow prop and plates. Aligning the props
will probably be the hardest bit.


michael adams

....








The two doors in the loft extention both
jam slightly in the frame, possibly due to this distortion.
I'm guessing the weight might have transferred to some other
part of the structure which might not be so well suited to
take it, although there's nothing else under that beam for
a few metres at least.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
(Andrew Gabriel) writes:
Helping a friend at the weekend, and found a roof leak has
caused the wallplate to disintegrate, which I removed with
the vacuum cleaner ;-)

Originally sitting on this was a sodding great compound beam
which runs the length of the house and has a loft extension

I did a sketch of the original construction (which is a bit
more complex than I described, with a separate roof plate):

http://www.cucumber.demon.co.uk/roof.jpg

(It's not to scale, as the rafters don't actually intersect
the outside wall, only the roof plate.)
The roof plate and wall plate immediately below the large
beam had rotted away, because the leadwork over the beam end
had failed. The beam itself was not damaged (I presume it's
pressure treated timber, whereas the much older wall plate
and roof plate are not). To answer another question, the
compound beam is just multiple 4" wide timbers around 18-24"
tall, fixed together with 18mm plywood on each side - no RSJ.

built on it. It was floating in mid air with the wall plate
having gone from under it, and has dropped about an inch from
where it originally was. I have for the time being packed
the gap under it with engineering bricks so it can't drop any
further, although before that I got friend to go and walk
around and then jump in the loft extention, and there was
virtually no movement in the beam-end (much less than 1mm).

So the question is, is it worth trying to jack the beam
back up by the inch it's dropped before reinstating the
support under it? The two doors in the loft extention both
jam slightly in the frame, possibly due to this distortion.
I'm guessing the weight might have transferred to some other
part of the structure which might not be so well suited to
take it, although there's nothing else under that beam for
a few metres at least.

Well, we did it. We jacked it up about 7/8" which was as
much as I was happy to do against the bathroom floor (which
deflected downwards an additional 1/8" under the weight).
I then built a brick pier of engineering bricks under the
beam end on top of the outside wall, left it for 5 days to
set. Added some sideways bracing so the beam can't slide
off the pier, and then let down the acro. All seems OK.
Roofer has temporarily fixed the leak with a resin mat
(he will be replacing the whole roof in the spring).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In message , Andrew Gabriel
writes
snip

Well, we did it. We jacked it up about 7/8" which was as
much as I was happy to do against the bathroom floor (which
deflected downwards an additional 1/8" under the weight).
I then built a brick pier of engineering bricks under the
beam end on top of the outside wall, left it for 5 days to
set. Added some sideways bracing so the beam can't slide
off the pier, and then let down the acro. All seems OK.
Roofer has temporarily fixed the leak with a resin mat
(he will be replacing the whole roof in the spring).

Nice sketch!

Job well done.




--
Tim Lamb

In article ,
Tim Lamb writes:
In message , Andrew Gabriel
writes
snip

Well, we did it. We jacked it up about 7/8" which was as
much as I was happy to do against the bathroom floor (which
deflected downwards an additional 1/8" under the weight).
I then built a brick pier of engineering bricks under the
beam end on top of the outside wall, left it for 5 days to
set. Added some sideways bracing so the beam can't slide
off the pier, and then let down the acro. All seems OK.
Roofer has temporarily fixed the leak with a resin mat
(he will be replacing the whole roof in the spring).

Nice sketch!

Google sketchup, so I can spin it round to find the best view.

Job well done.

Cheers.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]