Bowing house wall - tie rods?


G

Grunff

Background - our house was built in the 30s, has a square
footprint around 8x8m, and has no foundations to speak of. It's
made of stone + lime mortar, and the walls are between 50 and
60cm thick.

When we bought it 2 years ago, we noticed that the back wall had
at some point in the past bowed, so that while it's still
attached to the outer walls, it's come away from the internal
partition walls, causing a lot of cracks between the end wall
and the partitions, and the end wall and the ground floor ceilings.

We filled these cracks so that we may study future movement. Two
years on, the wall seems to have shifted by another mm or so.

The wall isn't sinking - there are no cracks at floor level
downstairs. The cracks appear about 1m above floor level, and
increase in size as you go upwards.

Similarly, the wall is still firmly attached to the two exterior
side walls. So it's only moving outwards in the middle. It's bowing.

I know the traditional fix for this is to tie the two opposing
walls together with steel tie rods, and spread the load on the
outside of the walls using steel plates.

I am considering doing this to our house. The obvious place to
run the steel rods is between the floor and ceiling. This would
be fine, since they'd run parallel to the joists.

Has anyone done this before, and do you have any advice to
offer? Is there anywhere when I could read up on this? Basic
stuff - like how big the rods should be, how big the plates
should be, how far apart, how many (two seems very common), that
kind of thing.

TIA
 
Ad

Advertisements

B

BigWallop

Grunff said:
Background - our house was built in the 30s, has a square
footprint around 8x8m, and has no foundations to speak of. It's
made of stone + lime mortar, and the walls are between 50 and
60cm thick.

When we bought it 2 years ago, we noticed that the back wall had
at some point in the past bowed, so that while it's still
attached to the outer walls, it's come away from the internal
partition walls, causing a lot of cracks between the end wall
and the partitions, and the end wall and the ground floor ceilings.

We filled these cracks so that we may study future movement. Two
years on, the wall seems to have shifted by another mm or so.

The wall isn't sinking - there are no cracks at floor level
downstairs. The cracks appear about 1m above floor level, and
increase in size as you go upwards.

Similarly, the wall is still firmly attached to the two exterior
side walls. So it's only moving outwards in the middle. It's bowing.

I know the traditional fix for this is to tie the two opposing
walls together with steel tie rods, and spread the load on the
outside of the walls using steel plates.

I am considering doing this to our house. The obvious place to
run the steel rods is between the floor and ceiling. This would
be fine, since they'd run parallel to the joists.

Has anyone done this before, and do you have any advice to
offer? Is there anywhere when I could read up on this? Basic
stuff - like how big the rods should be, how big the plates
should be, how far apart, how many (two seems very common), that
kind of thing.

TIA
Just reading the first part of your post and I would advise you to call in
an engineer to take a look. If this movement is continuois, then something
needs to be done to stop it. You say that it is opening further and further
every year, so it will eventually get the point of no return and may
collapse.

If the movement had taken years to open to a couple of millimeters, then it
is not as urgent, but as you say your problem is happening over a shorter
period of time, then it might just be safer to get it looked at.

Good luck with.

PS. And just another point. Ask your insurance company what they think.
(this came from the little woman sitting behind me, who seems to be up on
that sort of thing)
 
G

Grunff

BigWallop said:
Just reading the first part of your post and I would advise you to call in
an engineer to take a look. If this movement is continuois, then something
needs to be done to stop it. You say that it is opening further and further
every year, so it will eventually get the point of no return and may
collapse.
Well, yes, that's the obvious answer, but I'm looking for more
info at this stage.

TBH, I'm not terribly worried about the wall collapsing, because
[a] It's very unlikely to do so, given that it's stood this
long, and is supported by a great big stone porch on the
outside, and Even if it did, it really wouldn't be the end
of the world, and would give us a good reason to rebuild the house.

If the movement had taken years to open to a couple of millimeters, then it
is not as urgent, but as you say your problem is happening over a shorter
period of time, then it might just be safer to get it looked at.
It's been on the move since at least the 60s, because we found
some 1960s newspapers stuffed into one of the bigger cracks.

Good luck with.
Thanks. No google link? ;-)
 
J

John Laird

TBH, I'm not terribly worried about the wall collapsing, because
[a] It's very unlikely to do so, given that it's stood this
long, and is supported by a great big stone porch on the
outside, and Even if it did, it really wouldn't be the end
of the world, and would give us a good reason to rebuild the house.


[a] But you say it is still moving... What gives you confidence that the
movement will stop before it eventually collapses ? I don't think "it's
stood this long" is a particularly sound reason, engineering-wise !

Do you think this wall is non-structural ? What's to say your house
won't come down with it.

I think you ought to get a structural engineer to take a look (was anyone
other than a surveyor involved when you bought the place). You could start
off the whole process with a call to your insurers, but be warned that after
a claim you may be unable to ever change companies.

I had a bulging back wall re-tied as part of the mortgage conditions on my
house - the outer leaf had come adrift from the inner (structural) wall.
 
T

The Natural Philosopher

John Laird wrote:

I think you ought to get a structural engineer to take a look (was anyone
other than a surveyor involved when you bought the place). You could start
off the whole process with a call to your insurers, but be warned that after
a claim you may be unable to ever change companies.

Structural engineer is MANDATORY. NOT expensive either usually. DO WHAT
THEY SAY and then you can sue them - or your insurance company can, when
the house falls down.

Its really not expensive to put a tie rod through and tighten up the bolts.

Just make sure its as specified by certified engineers with liability insurance.

Then you are covered against mistakes.
 
G

Grunff

John said:
Do you think this wall is non-structural ? What's to say your house
won't come down with it.


No, the wall most certainly *is* structural, and the house would
most definitely come down with it. But that wouldn't be the end
of the world. That's what I'm saying.

I think you ought to get a structural engineer to take a look (was anyone
other than a surveyor involved when you bought the place). You could start
off the whole process with a call to your insurers, but be warned that after
a claim you may be unable to ever change companies.
Hmm..maybe. No, we didn't have a structural survey done (we were
fully aware of the problem).
 
Ad

Advertisements

G

Grunff

The said:
Structural engineer is MANDATORY. NOT expensive either usually. DO WHAT
THEY SAY and then you can sue them - or your insurance company can, when
the house falls down.
What qualifications should one look for in a structural
engineer? Are all structural engineers listed in the yellow
pages equal?
 
D

Darren Griffin

Grunff said:
No, the wall most certainly *is* structural, and the house would
most definitely come down with it. But that wouldn't be the end
of the world. That's what I'm saying.
It may well be the end of your world if you are in the house when it comes
down.
 
G

Grunff

Darren said:
It may well be the end of your world if you are in the house when it comes
down.
I think it has a fair way to move before that happens, and would
be pretty obvious that something bad is about to happen. Houses
very rarely spontaneously self destruct without warning.
 
J

James Salisbury

Grunff said:
What qualifications should one look for in a structural
engineer? Are all structural engineers listed in the yellow
pages equal?
Try a Chartered Civil or Structrual engineer, a decent engineer needs C Eng
after her or his name.
 
P

PoP

I am considering doing this to our house. The obvious place to
run the steel rods is between the floor and ceiling. This would
be fine, since they'd run parallel to the joists.
As others have said, and perhaps to lend weight as if we were voting
on the next step, I'd consult someone who knows what they are talking
about. And your insurance company should be part of the deal.

It is possible that your insurance company has a get-out clause buried
in the fine print, in so far that at the time you purchased the
property there was a problem. That should have been noted by the
surveyor who inspected prior to purchase. Depending on his description
may be whether the insurance company feel they are liable (and like
all insurance companies their starting gambit will tend to be "not us,
guv!").

Remember that the Titanic didn't sink instantly after coming into
contact with a block of frozen water.

PoP
 
Ad

Advertisements

B

BigWallop

Grunff said:
I think it has a fair way to move before that happens, and would
be pretty obvious that something bad is about to happen. Houses
very rarely spontaneously self destruct without warning.
Please say your not sure. All it can take is some ground movement or a
heavy lorry passing the building, to take any precarious structure over the
edge. Do you know that the joist are still properly seated on their
retainers ? Have the joists moved out of their original position and are
now sitting on crumbling mortar.

A low flying jet from RAF Leuchars, brought down a cottage in the wilds of
the Ayrshire country side. So please, if you can see that the movement is
continuing at a pretty even rate over short periods of time, then have it
looked at properly. We'd all miss you.
 
G

Grunff

John said:
Are you sure its not the porch that is sinking and pulling the wall with
it?
I don't think so. First off, the wall isn't sinking - there's no
movement at ground level. It's bulging out, greatest bulge at
the centre of the wall. Second, I don't believe the porch walls
are tied in to the bulging wall - it appears to have just been
built there, in contact with but not attached to the wall.
 
J

John Rumm

Grunff said:
supported by a great big stone porch on the outside, and Even if it


Are you sure its not the porch that is sinking and pulling the wall with it?
 
G

Grunff

BigWallop said:
Please say your not sure. All it can take is some ground movement or a
heavy lorry passing the building, to take any precarious structure over the
edge. Do you know that the joist are still properly seated on their
retainers ? Have the joists moved out of their original position and are
now sitting on crumbling mortar.
Greatest deflection is aout 30mm, over 70 years. The joists are
still nicely in their holes, that was one of the first things I
checked.

We'd all miss you.
I'm touched...

I will be doing something about it - don't worry. Just getting
the group's thoughts first. I like to understand things. I'm
trying to understand what possible solutions may exist. I like
to have this information before calling in someone who may or
may not know what they're talking about.
 
G

Grunff

Dave said:
Ummm, run, run very fast. Run now.

Seriously, it must have foundations or it wouldn't stil be up.
Ok, it has some very shallow stone foundations. No deeper than a
foot.

I remember Fred Dibnah doing this to his house in his tv program. I think
you'll find the rods and plates are pretty much of a std size unless it's a
castle you're trying to shore up. The plates are about 1 foot in diameter (or
they can be crosses) and the rods are about an inch. Two in 8m sounds plenty. A
1 inch mild steel bar will withstand over 20 tons and there'll be nothing like
that sort of force pulling at your walls or they'd be down by now.
Sounds reasonable.

I read through the thread before posting and the bit about the front porch is
worrying. If the walls are bowing but not sinking and the porch is still
attached to the walls then the porch must be sinking or something else would
have had to crack. I think the porch could well be your problem.
I know - it's puzzled me too. I concluded that the bowing wall
must be pushing the porch out with it. I think if the porch was
going to sink it would just detatch from the house. I could be
wrong.
 
Ad

Advertisements

R

Richard Faulkner

Grunff said:
We filled these cracks so that we may study future movement. Two
years on, the wall seems to have shifted by another mm or so.

The wall isn't sinking - there are no cracks at floor level
downstairs. The cracks appear about 1m above floor level, and
increase in size as you go upwards.
What are you waiting for - are you skint? a cheapskate? stupid? naeive?
..........

Get a structural engineer in fast. It will cost around £175 to £400 or
so, for a visual inspection, initial prognosis and advice for further
inspection and/or cure.

The longer you leave it, the more chance of having to rebuild the wall
than using simple metal strapping.

I would get the engineer 1st - before involving your insurance co.. You
may not need, or want, to bother with insurance.

This is not Do It Yourself - you need the correct paperwork to satisfy a
surveyor when you sell.
 
G

Grunff

Richard said:
What are you waiting for - are you skint? a cheapskate? stupid? naeive?
..........
None of the above. I'm ... laid back.

This is not Do It Yourself - you need the correct paperwork to satisfy a
surveyor when you sell.
What is the correct paperwork? This is exactly why I posted my
question.
 
O

Owain

| > What qualifications should one look for in a structural
| > engineer? Are all structural engineers listed in the yellow
| > pages equal?
| Try a Chartered Civil or Structrual engineer, a decent engineer needs
| C Eng after her or his name.

You want a Structural Engineer who will be MIStructE (Member of the
Institute of Structural Engineers - www.istructe.org.uk but I don't think
they have an online member listing[1]) and CEng as well.

Owain

[1] They do have http://www.findanengineer.com/ but it's a paid-for listing
rather than a comprehensive register of members. You could try a local
reference library for the IStructE Sessional Yearbook and Directory of
Members
 
Ad

Advertisements

R

Richard Faulkner

Grunff said:
None of the above. I'm ... laid back.
but you wont know when it moves said:
What is the correct paperwork? This is exactly why I posted my
question.
A Structural Engineers report with diagnosis and requirements.

A builders invoice for completion of said requirements

A Structural Engineers Certificate or letter of satisfaction with the
work.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Similar Threads

garden wall tied to house 5
New sill plate, old tie rod? 3
Rod's house 5
Wall ties 1
Wall Tie Worries 7
Ground Rod For House ? 25
Cavity wall ties. 2
Deteriation of cavity wall ties 22

Top