Wall tie replacement?
Discussion
Random question of the day...!
It seems that my house will require the replacement of the wall ties in the near future and at the moment we are still reeling from the potential impact of this - the cost alone is possibly extreme!
Just reaching out (to use an American term) to anyone else who may have had this done. Looking at options, ideas and any recommended companies / processes that anyone used. Just starting out on a potential bank-breaker and experience and ideas are more than welcome.
The structural engineer has warned that insurance does not cover this - so 'interesting' finance options might be considered.....
Thanks in advance by the way.
It seems that my house will require the replacement of the wall ties in the near future and at the moment we are still reeling from the potential impact of this - the cost alone is possibly extreme!
Just reaching out (to use an American term) to anyone else who may have had this done. Looking at options, ideas and any recommended companies / processes that anyone used. Just starting out on a potential bank-breaker and experience and ideas are more than welcome.
The structural engineer has warned that insurance does not cover this - so 'interesting' finance options might be considered.....
Thanks in advance by the way.
How have you been told to do this?
Have seen it done two ways.
On a commercial building had the problem that the builders had not put in wall ties and the inner and outer walls were separating. They took parts of the outer skin off and put ties in.
Have seen a house here where the internal ties had failed and the fix was to plate inside and out to spread load with a threaded bar running through the plates and the whole lots put under tension to hold the walls square. About 6 of these were along one wall.
Now the building regs here are much more lax, but it seems a sensible approach if the problem isn't too bad.
Have seen it done two ways.
On a commercial building had the problem that the builders had not put in wall ties and the inner and outer walls were separating. They took parts of the outer skin off and put ties in.
Have seen a house here where the internal ties had failed and the fix was to plate inside and out to spread load with a threaded bar running through the plates and the whole lots put under tension to hold the walls square. About 6 of these were along one wall.
Now the building regs here are much more lax, but it seems a sensible approach if the problem isn't too bad.
First of all I wouldn't assumme that it's not covered by insurance. We certainly know of at least one property where it was covered.
The extent of the work required depends to some extent on the damage. Your engineer has probably been through all this with you. Wall tie replacement does not mean that existing wall ties have to be removed and replaced. They can stay in situ, although the cavity should ideally be filled to prevent moisture attack making the situation worse. A pattern of additional ties is normally inserted by drilling a hole through both leaves of the wall and a stainless steel tie is resin bonded to each leaf. Plenty of specialist companies exist to do this.
If the failure has been identified by some defect manifesting itself then there may be further repairs required.
I'd make a call to the insurers in the first instance. This is not a defect caused by lack of maintenance, it's what we call a latent defect (some would say inherent defect, but that's largely semantics). The worst they can say is no. Whilst there would be an excess to pay, it's got to be better than paying for the whole lot.
If you could describe the problem a little more I'm sure the PH construction possee will be throwing their guidance in as well.
This has some basic information which may help.
http://www.petercox.com/pdf/Wall-Tie-Failure-06.pd...
The extent of the work required depends to some extent on the damage. Your engineer has probably been through all this with you. Wall tie replacement does not mean that existing wall ties have to be removed and replaced. They can stay in situ, although the cavity should ideally be filled to prevent moisture attack making the situation worse. A pattern of additional ties is normally inserted by drilling a hole through both leaves of the wall and a stainless steel tie is resin bonded to each leaf. Plenty of specialist companies exist to do this.
If the failure has been identified by some defect manifesting itself then there may be further repairs required.
I'd make a call to the insurers in the first instance. This is not a defect caused by lack of maintenance, it's what we call a latent defect (some would say inherent defect, but that's largely semantics). The worst they can say is no. Whilst there would be an excess to pay, it's got to be better than paying for the whole lot.
If you could describe the problem a little more I'm sure the PH construction possee will be throwing their guidance in as well.
This has some basic information which may help.
http://www.petercox.com/pdf/Wall-Tie-Failure-06.pd...
Thanks chaps, very useful to start with.
Unfortunately I am out of the country and my wife very kindly dealt with the structural engineer when he came around to answer some basic stuff. I guess the positive thing here is that we at least got someone in sooner rather than later to give us the bad news. I hate to think that we would have let this go on longer and been in a much more difficult situation. Still, chin up and all of that.
A couple of quick answers as internet access is limited and costly for me at the moment:
1) Its a domestic house - mine
2) There are already some cracks and some shifting, though certainly not excessive - small cracks internally in plaster work, but some crack on external brick work too. Not massive though.
3) Its an Edwardian house and there is some evidence of corroded metal wall ties and hence expansion of them causing damage
4) The mortar has some ash content and hence potentially causes faster damage to the wall ties
5) Damage seems to be on one wall predominantly at the moment. Other walls don't look as bad and not sure of the impact.
I will get a specialist company round ASAP to have a proper survey done to assess the actual damage with an endoscope etc, but I guess its just guess work until this occurs. Its interesting to hear about potential bonding and plates, as my fear is of the whole drill / remove brick work / new ties / refit brick process strikes me as very expensive and time consuming to complete.
Anyway, any comments and ideas are more than welcome. I am not back in the country until friday, so replies might be a little delayed... And thanks in advance.
Unfortunately I am out of the country and my wife very kindly dealt with the structural engineer when he came around to answer some basic stuff. I guess the positive thing here is that we at least got someone in sooner rather than later to give us the bad news. I hate to think that we would have let this go on longer and been in a much more difficult situation. Still, chin up and all of that.
A couple of quick answers as internet access is limited and costly for me at the moment:
1) Its a domestic house - mine
2) There are already some cracks and some shifting, though certainly not excessive - small cracks internally in plaster work, but some crack on external brick work too. Not massive though.
3) Its an Edwardian house and there is some evidence of corroded metal wall ties and hence expansion of them causing damage
4) The mortar has some ash content and hence potentially causes faster damage to the wall ties
5) Damage seems to be on one wall predominantly at the moment. Other walls don't look as bad and not sure of the impact.
I will get a specialist company round ASAP to have a proper survey done to assess the actual damage with an endoscope etc, but I guess its just guess work until this occurs. Its interesting to hear about potential bonding and plates, as my fear is of the whole drill / remove brick work / new ties / refit brick process strikes me as very expensive and time consuming to complete.
Anyway, any comments and ideas are more than welcome. I am not back in the country until friday, so replies might be a little delayed... And thanks in advance.
I had our cavity wall ties replaced a few months ago (due to mortgage requirements)
5 bed detached house was £750 - hope this helps
Editted to add : our mortgage valation report highlighted the house was built (1930's) at a time when they used crappy wall ties and probably one in a million or so has failed because of said crappy ties) therefore insisted we have it done.
Our survery and the wall tie engineers agreed it was not required..
5 bed detached house was £750 - hope this helps
Editted to add : our mortgage valation report highlighted the house was built (1930's) at a time when they used crappy wall ties and probably one in a million or so has failed because of said crappy ties) therefore insisted we have it done.
Our survery and the wall tie engineers agreed it was not required..
Edited by Soir on Thursday 18th March 14:36
Without trying to sound smart, does an Edwardian house have wall ties?
I ask because cavity walls were not common before 1920's according to my research. We moved to a chapel conversion last year. Partly built in 1909 and of Accrington brick. Our surveyor suggested that the wall ties might need attention on the report.
However on close inspection the brick pattern shows it to be solid walls with no cavity. Ergo no wall ties. The brick pattern is called american common bond. Every few rows of brick the row is end on not side on. This means it is a solid wall. The end on bricks keep the two skins together.
How has it come about that you are having a survey done? Any house of that age is bound to have some settlement cracking both inside and out which may be years old.
I'm not trying to be smart and i'm sure you've done your homework but i'm always suspect of wall tie failure reports. Unless there is obvious bowing or movement in recent times I would suggest that there is really no issue to be resolved.
I ask because cavity walls were not common before 1920's according to my research. We moved to a chapel conversion last year. Partly built in 1909 and of Accrington brick. Our surveyor suggested that the wall ties might need attention on the report.
However on close inspection the brick pattern shows it to be solid walls with no cavity. Ergo no wall ties. The brick pattern is called american common bond. Every few rows of brick the row is end on not side on. This means it is a solid wall. The end on bricks keep the two skins together.
How has it come about that you are having a survey done? Any house of that age is bound to have some settlement cracking both inside and out which may be years old.
I'm not trying to be smart and i'm sure you've done your homework but i'm always suspect of wall tie failure reports. Unless there is obvious bowing or movement in recent times I would suggest that there is really no issue to be resolved.
Z4monster said:
How has it come about that you are having a survey done? Any house of that age is bound to have some settlement cracking both inside and out which may be years old.
Needed a structural engineers report for some other bits and bobs on the house - nothing major but non-supporting walls and window strength type of stuff. Took the advantage at the time to get the cracks that I had noticed to be investigated. Ignorance might just have been bliss..... Z4monster said:
I'm not trying to be smart and i'm sure you've done your homework but i'm always suspect of wall tie failure reports. Unless there is obvious bowing or movement in recent times I would suggest that there is really no issue to be resolved.
Assume nothing I am afraid. This really did come as a bolt out of the blue! It was one of those 'can you just cast your eyes on this for a minute and see what you think' moments. Kinda wishing we didn't now, but hey better informed rather than not. So unfortunately this is the beginning of the process rather than further along. Any information is gratefully received and lets face it, independent information is even better...There has been some movement in the last few years with a few small cracks - nothing major and its pretty easy to see the damage that winter has had on walls all over the place, so kinda assumed that it was the extended cold and frost periods. Turns out it is much more. But, need to sort out a proper report from a specialist company to fully assess the damage.
More likely to be resulting from the very dry summers.
One of our rentals has suffered badly in last couple of years. Is a 1920's semi. Very limited footings and where the earth has dried out and the water table dropped the house has shifted.
It isn't moving anymore and we have adopted a wait and see attitude. As have the neighbours.
My main worry would be a series of wet summers and a raising of the water table causing more shifts.
One of our rentals has suffered badly in last couple of years. Is a 1920's semi. Very limited footings and where the earth has dried out and the water table dropped the house has shifted.
It isn't moving anymore and we have adopted a wait and see attitude. As have the neighbours.
My main worry would be a series of wet summers and a raising of the water table causing more shifts.
The cracking for cavity wall tie failure is fairly characteristic, so your engineer is unlikely to confuse it with foundation failure etc..
The need to remove the existing ties very much depends on the type of mortar and the type of tie - if you have cracking to the external leaf beyond hairline, I'd suggest they may need removing - but the good news is that usually it is sufficient to remove one brick and crop off the outer half only.
The type of tie depends on what the walls are made of, but various types of expansion fixings (rather like Rawlbolts), resin anchors, and combinations of both in one tie, are available to suit differing inner and outer leaves.
I would caution against "filling the cavity to prevent damp" (whatever that means) - usually the corrosion is concentrated in the outer leaf, which is after all designed to get wet.
The need to remove the existing ties very much depends on the type of mortar and the type of tie - if you have cracking to the external leaf beyond hairline, I'd suggest they may need removing - but the good news is that usually it is sufficient to remove one brick and crop off the outer half only.
The type of tie depends on what the walls are made of, but various types of expansion fixings (rather like Rawlbolts), resin anchors, and combinations of both in one tie, are available to suit differing inner and outer leaves.
I would caution against "filling the cavity to prevent damp" (whatever that means) - usually the corrosion is concentrated in the outer leaf, which is after all designed to get wet.
I may be of some help here as I did work for a Company many years ago that jumped on the wall tie replacement band wagon.
Firstly an endoscope is of little help unless the tie is severely corroded, ie separated, which is very rare. It is essential that you have a couple of bricks removed so that you can see the end of the tie with the naked eye, lots of things look like corrosion through an endoscope when you're trying to get a job out of it. You can find the ties with a basic metal detector.
You probably have fishtail ties, which are thicker than the more modern butterfly ones, so if they do rust they will expand and can cause cracking as you say. However it is very rare that you get cracking on the inner leaf. Fitting new ties is quite cheap, as has been said, but isolating with grease filled plastic caps or removing the old ones is labour intensive and expensive.
I feel I must reiterate, don't instruct any work unless you have physically seen a corroded tie. Very few of the houses the Company I worked for specified work on actually needed doing, although this wasn't apparent until you were isolating the ties and found they were as new.
Firstly an endoscope is of little help unless the tie is severely corroded, ie separated, which is very rare. It is essential that you have a couple of bricks removed so that you can see the end of the tie with the naked eye, lots of things look like corrosion through an endoscope when you're trying to get a job out of it. You can find the ties with a basic metal detector.
You probably have fishtail ties, which are thicker than the more modern butterfly ones, so if they do rust they will expand and can cause cracking as you say. However it is very rare that you get cracking on the inner leaf. Fitting new ties is quite cheap, as has been said, but isolating with grease filled plastic caps or removing the old ones is labour intensive and expensive.
I feel I must reiterate, don't instruct any work unless you have physically seen a corroded tie. Very few of the houses the Company I worked for specified work on actually needed doing, although this wasn't apparent until you were isolating the ties and found they were as new.
Use the Helix tie replacement system, bit goes in a drill and threads the ties throught the outer skin and into the inner, after youv'e drilled a hole of course. Did mine over a course of a weekend for about £150 including the tool( Which I still have!)Cannot move them once they're in then just muck in the holes!
Recommended for all insurance and mortgages too!
Recommended for all insurance and mortgages too!
Quick update on this. I had one specialist come around to give a quote (verbal at the moment) and it looks that its certainly NOT as bad as was originally thought. Needs a bit further investigation, but so far looking at around 1.5k in total. Seems that the parts that I thought were bad aren't and the bits that I thought were OK aren't. But hey ho, shows how much I know - and why I am not a builder.
So happy days as I can afford that. Interestingly though, spoke to the bank about this and they have offered a number of financial methods of financing this if necessary. So there are options to working this through should the worst come to the worst. Its just nice to know I have options....
Thanks all for the help and suggestions.
So happy days as I can afford that. Interestingly though, spoke to the bank about this and they have offered a number of financial methods of financing this if necessary. So there are options to working this through should the worst come to the worst. Its just nice to know I have options....
Thanks all for the help and suggestions.
One of the classic comments on surveys when we bought our bungalow back in the 80's was - "Possible early signs of wall tie failure"
One survey we had done even made that statement for a stone built house - needless to say I refused to pay the surveyor's bill.
Classic symptoms of wall-tie corrosion are horizontal hairline cracking between the courses of bricks.
TBH and IMO the old ties should really be removed from the external skin if at all possible as if they are left there they will/can continue to corrode and cause problems in the future (more hairline cracks in the new render/paintwork in a few years)
I did ours myself about 25 years back during a full renovation. Took the old ties out of the outer skin, drilled through from the outside into the inner skin and used a propriatory resin to 'glue' them in. Put one in the wrong place and had to remove it a few days later and have never doubted the strength of resin since.
Don't need to be a professional to do it - just a competant DIYer with a bit of time and common sense.
HTH
BB
One survey we had done even made that statement for a stone built house - needless to say I refused to pay the surveyor's bill.
Classic symptoms of wall-tie corrosion are horizontal hairline cracking between the courses of bricks.
TBH and IMO the old ties should really be removed from the external skin if at all possible as if they are left there they will/can continue to corrode and cause problems in the future (more hairline cracks in the new render/paintwork in a few years)
I did ours myself about 25 years back during a full renovation. Took the old ties out of the outer skin, drilled through from the outside into the inner skin and used a propriatory resin to 'glue' them in. Put one in the wrong place and had to remove it a few days later and have never doubted the strength of resin since.
Don't need to be a professional to do it - just a competant DIYer with a bit of time and common sense.
HTH
BB
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