Looking at buying a 1900 cavity wall house, which needs the wall ties
replacing due to failure of the original ties.

I have had a quote for the work, but with no mention of removing the old
ties.

The survey picked up some cracking in the brickwork, attributed to the old
ties corroding and expanding.

The replacement ties will obviously bring the wall back up to strength, but
if the old ties are left in, will the corrosion cause further damage to the
wall?

If the old ties do have to come out, how are they removed?

"SimonJ" wrote in message
news
Looking at buying a 1900 cavity wall house, which needs the wall ties
replacing due to failure of the original ties.

I have had a quote for the work, but with no mention of removing the old
ties.

The survey picked up some cracking in the brickwork, attributed to the old
ties corroding and expanding.

The replacement ties will obviously bring the wall back up to strength,
but if the old ties are left in, will the corrosion cause further damage
to the wall?

If the old ties do have to come out, how are they removed?

No. They only have to be stopped from expanding into the brickwork around
them and damaging it. What happens is they drill holes through the centre of
bricks for the new ties and epoxy them in place at both ends, plugging the
outer part of the holes with a mix of epoxy and brick dust from the
drilling. Then a chap with a rotary file in a power drill cuts the mortar
away from around the existing ties, leaving a cavity around them. The holes
created by this are simply re-pointed with no mortar behind the pointing,
leaving the outer end of the old ties floating in a hole. The inner ends of
the ties don't rust in the same way, so can be left in place.

Colin Bignell

"nightjar .me.uk" cpb@insert my surname here wrote in message
...

"SimonJ" wrote in message
news
Looking at buying a 1900 cavity wall house, which needs the wall ties
replacing due to failure of the original ties.

I have had a quote for the work, but with no mention of removing the old
ties.

The survey picked up some cracking in the brickwork, attributed to the
old ties corroding and expanding.

The replacement ties will obviously bring the wall back up to strength,
but if the old ties are left in, will the corrosion cause further damage
to the wall?

If the old ties do have to come out, how are they removed?

No. They only have to be stopped from expanding into the brickwork around
them and damaging it. What happens is they drill holes through the centre
of bricks for the new ties and epoxy them in place at both ends, plugging
the outer part of the holes with a mix of epoxy and brick dust from the
drilling. Then a chap with a rotary file in a power drill cuts the mortar
away from around the existing ties, leaving a cavity around them. The
holes created by this are simply re-pointed with no mortar behind the
pointing, leaving the outer end of the old ties floating in a hole. The
inner ends of the ties don't rust in the same way, so can be left in
place.

Colin Bignell


What intrigues me is how do they know precisely where the ties are to be
able to drill round them?

Rob Graham

In article ,
"robgraham" writes:

What intrigues me is how do they know precisely where the ties are to be
able to drill round them?

No idea, but endoscope and metal detector probably get you near enough.

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

"Andrew Gabriel" wrote in message
...
In article ,
"robgraham" writes:

What intrigues me is how do they know precisely where the ties are to be
able to drill round them?

No idea, but endoscope and metal detector probably get you near enough.

I would imagine they could just run a tct cutter along the mortar removing
half of it and exposing the ties.
Then re-point.

In article ,
"dennis@home" writes:


"Andrew Gabriel" wrote in message
...
In article ,
"robgraham" writes:

What intrigues me is how do they know precisely where the ties are to be
able to drill round them?

No idea, but endoscope and metal detector probably get you near enough.

I would imagine they could just run a tct cutter along the mortar removing
half of it and exposing the ties.
Then re-point.

Sounds like a good way to have the wall collapse on you.

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

Andrew Gabriel wrote:
In article ,
"dennis@home" writes:
"Andrew Gabriel" wrote in message
...
In article ,
"robgraham" writes:

What intrigues me is how do they know precisely where the ties are to be
able to drill round them?

No idea, but endoscope and metal detector probably get you near enough.

I would imagine they could just run a tct cutter along the mortar removing
half of it and exposing the ties.
Then re-point.

Sounds like a good way to have the wall collapse on you.

Yes, just do it patch by patch. I wouldnt want to run into an iron tie
with a coarse cutter though.


NT

On May 14, 8:34*am, "robgraham" wrote:
"nightjar .me.uk" cpb@insert my surname here wrote in messagenews:LbqdnT5ZtLAzI5bXnZ2dnUVZ8tqdnZ2d@gigan ews.com...







"SimonJ" wrote in message
news
Looking at buying a 1900 cavity wall house, which needs the wall ties
replacing due to failure of the original ties.

I have had a quote for the work, but with no mention of removing the old
ties.

The survey picked up some cracking in the brickwork, attributed to the
old ties corroding and expanding.

The replacement ties will obviously bring the wall back up to strength,
but if the old ties are left in, will the corrosion cause further damage
to the wall?

If the old ties do have to come out, how are they removed?

No. They only have to be stopped from expanding into the brickwork around
them and damaging it. What happens is they drill holes through the centre
of bricks for the new ties and epoxy them in place at both ends, plugging
the outer part of the holes with a mix of epoxy and brick dust from the
drilling. Then a chap with a rotary file in a power drill cuts the mortar
away from around the existing ties, leaving a cavity around them. The
holes created by this are simply re-pointed with no mortar behind the
pointing, leaving the outer end of the old ties floating in a hole. The
inner ends of the ties don't rust in the same way, so can be left in
place.

Colin Bignell

What intrigues me is how do they know precisely where the ties are to be
able to drill round them?


perhaps they locate them by seeing the external damage that their
expansion is causing.

R

"dennis@home" wrote:
What intrigues me is how do they know precisely where the ties are to be
able to drill round them?

No idea, but endoscope and metal detector probably get you near enough.

I would imagine they could just run a tct cutter along the mortar removing
half of it and exposing the ties.
Then re-point.

Nope. We had this done last year and they only remove small sections of
pointing around the end of the corroding wall ties.

On 14 May, 08:34, "robgraham" wrote:
What intrigues me is how do they know precisely where the ties are to be
able to drill round them?

Same way you can tell that the cracking is caused by rusted wall ties
expanding and blowing the joint, rather than any old movement - the
crack pattern is quite distinctive.

If you're hacking the old ties with a 9" wheel (as used to be done),
this is quite accurate enough. If you're using a cylindrical mortar
rake cutter, then a simple wall stud detector is usual. These old ties
are quite hefty, they're not the modern stainless steel thin wires.

"Andrew Gabriel" wrote in message
...
In article ,
"dennis@home" writes:


"Andrew Gabriel" wrote in message
...
In article ,
"robgraham" writes:

What intrigues me is how do they know precisely where the ties are to
be
able to drill round them?

No idea, but endoscope and metal detector probably get you near enough.

I would imagine they could just run a tct cutter along the mortar
removing
half of it and exposing the ties.
Then re-point.

Sounds like a good way to have the wall collapse on you.

A wall won't collapse if it has half the mortar still in the joints.
They are external walls so they don't actually carry any more weight than
the wall.
You do it in sections anyway, just as you would do to insert a DPM.

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

"robgraham" wrote in message
...
....
What intrigues me is how do they know precisely where the ties are to be
able to drill round them?

When they did my house, you could see one or two places where the bricks
were spalled due to tie expansion. Brick layers follow a pattern when
putting the ties in, so once you have one, you can quickly find the others
by counting bricks across and rows up or down. As a final check, the chap
used a hand-held metal detector, but I didn't see him get any wrong.

Colin Bignell

SimonJ wrote:
Looking at buying a 1900 cavity wall house, which needs the wall ties
replacing due to failure of the original ties.

I have had a quote for the work, but with no mention of removing the
old ties.

The survey picked up some cracking in the brickwork, attributed to
the old ties corroding and expanding.

The replacement ties will obviously bring the wall back up to
strength, but if the old ties are left in, will the corrosion cause
further damage to the wall?

If the old ties do have to come out, how are they removed?

They aren't removed, they are isolated, so when you next speak to someone
about the wall ties, make sure you ask for the old ties to be isolated as
your first quote doesn't cover this - expect the quote to be considerably
higher.

To isolate the old ties, the mortar is cut away from them top and bottom and
a plastic sleeve filled with grease is inserted over them and then pointed
over.

--
Phil L
RSRL Tipster Of The Year 2008