Identifying root cause of water ingress from outer to inner leaf - cavity wall

makeorbrake · 13-07-2016 08:21PM

There has been some further 'movement' and waiting for it to be put in writing but it looks like they will cover all 3 walls on the basis of render failure.

If I leave aside any further potential root causes for right now and work on the assumption that it is render failure, could I build up that wall with the addition of an external insulation rendered finish?

i.e. block on side (inner leaf) -> 100mm bonded bead insulation -> block on side (outer leaf) -> external insulation with rendered finish.

Does that build-up work or will it cause issues? If it can work, is there any waterproof membrane that could be placed between outer-leaf and EWI to prevent future water ingress (in the event of some future render failure catastrophe)?

Also, is the existing bonded bead insulation contaminated/compromised on the basis that it's been saturated?

They are of a mind that - sure, mortar snots on wall ties are against regs and bad practice but that they're not a structural issue as such....ergo...they are washing their hands of that aspect of things. I would contend that it is an element of the overall failure - and want to propose the solution above (EWI) to deal with that (and also the cold bridging that its responsible for).

Metric Tensor · 15-07-2016 10:49PM

I would personally be very wary of just re-rendering based on the problems you exposed - you are also wary of this I think! I would be looking to separate the rain protection from the underlying structure - a rain screen like CH suggested may be a good idea. A few thoughts that spring to mind:

Would EWI or any waterproofing item trap any existing moisture within the wall?
Some sort of vented cavity may be more appropriate? - but then the insulation value might not be great.
What is the proposed method of treating the existing cracks?

I don't know what the condition of the bead would be or what might happen if it's wet or even it may dry out over time. Your best bet there might be talking to a bead supplier.

Also just to aid you in future discussions - what you call "block on side" is usually called "block on edge" - nothing wrong with what you said but it might make it easier for you discussing it with tradespeople (vs. block on flat being the alternative)

makeorbrake · 16-07-2016 12:18PM

Metric Tensor wrote: »

I would personally be very wary of just re-rendering based on the problems you exposed - you are also wary of this I think!

I am for sure, however, I have to do some careful weighing up - as it could be this or a protracted legal scenario (and in Ireland, that can sometimes be like rolling a set of dice!).

Metric Tensor wrote: »

I would be looking to separate the rain protection from the underlying structure - a rain screen like CH suggested may be a good idea.

I guess I never really understood the detail of how what CH suggested worked. Would this be such a system? Can these systems be used in tandem with external insulation and should I be proposing use of this on all wall facades or just the gable (as it seems that they are accepting that all facades come into the scope now).?

Metric Tensor wrote: »

Some sort of vented cavity may be more appropriate? - but then the insulation value might not be great.
What is the proposed method of treating the existing cracks?

Still waiting on full confirmation on paper but I'd imagine they're talking in terms of stripping back the render in total and re-rendering.

Is there a need to strip back render if using a wall screen solution or could it be left in situ? Just wondering if I could use that as a reason in steering them towards a rain screen (or rain screen + external insulation ?) solution?

makeorbrake · 27-07-2016 11:23AM

As expected, the remediation proposal involves removal of render from all facades, re-render with sand-cement nap finish - paint. Internal: Remove plaster and re-do - paint.

In the meantime, I've been checking out rain screen options - but any of the companies I've contacted - their solutions won't allow for a rendered finish (My house is a semi D in an estate - I can't have it looking completely different than every other property - and particularly, the adjoining property).

Initially, they wouldn't accept my claim on the basis of render failure alone - without me demonstrating how the water was getting in. Subsequently, they are saying that mortar snots - although against building regs - are not a structural element.
They've also more or less admitted that bonded bead should never have been used in this particular location - as a full cavity fill. However, that's not being addressed in the remediation plan.

I wanted to counter with the rainscreen (including external insulation - given that, as well as contributing to water ingress between the mortar snots and angle of the ties, it's leaving my house with multiple cold bridges that shouldnt otherwise be there) idea but it looks like that's a non-runner. Could I just suggest external insulation alone as a better solution? i.e. does that stand more chance of keeping water out as the boards are rigid?

Is it true to say that any render cannot guarantee to keep out driving rain?

Are there any consequences to that bonded bead cavity fill having been saturated?

Metric Tensor · 27-07-2016 11:41AM

Personally I think the external insulation option, although not specifically designed to do so, would provide a reasonable amount of extra weather tightness to the wall. Bear in mind that the render is not specifically meant to be weather resistant either - that's what your cavity is for.

So essentially either of these proposals is relying on a render to provide weather tightness to a cavity wall - that's not what the render is for. That's what the cavity is for. (Although it must be recognised that the render is probably doing this job, that it's not meant to, in 50% of Irish houses!)

My big worry would be that both of these options will act in reverse too - locking the existing moisture into the wall. I've not idea what the long term consequences if any of same would be.

makeorbrake · 01-08-2016 04:56PM

Thanks as always for your post - didn't reply until now as have been trying to figure out how best to approach this..

Metric Tensor wrote: »

Personally I think the external insulation option, although not specifically designed to do so, would provide a reasonable amount of extra weather tightness to the wall. Bear in mind that the render is not specifically meant to be weather resistant either - that's what your cavity is for.

I've a query in with Weber - they seem to have an External Insulation system that is fixed to aluminium rails - allowing for a small gap - which I would imagine would help in preventing future water ingress.

Metric Tensor wrote: »

My big worry would be that both of these options will act in reverse too - locking the existing moisture into the wall. I've not idea what the long term consequences if any of same would be.

I wondered the same thing myself. It's a bit of a conundrum. I could take the view that they have to remove the existing full fill insulation - and clean up compromised wall ties. However, even though the liability is theirs, it's probably a big ask - i.e. I'm not sure they could get at it without tearing down that outer leaf - and then we're into a much bigger claims situation - one I'm sure they may not be too keen to agree on.
What I was thinking was that the external side of things be taken care of - and that addressing the internal damage is delayed - so that it can be assessed if moisture ingress is still happening i.e. that there's still so much moisture already stuck in there for it to cause an issue. That's the only way I can think of approaching it...if it makes any sense?

makeorbrake · 29-10-2016 07:18PM

If a structural insurer maintains as part of their remediation plan that you have to move out of your property for X number of weeks, who picks up the tab?

kieran. · 30-10-2016 08:58AM

The Ewi solution on rails renders the insulation useless as the ventilated cavity is on the internal side of the insulation. Personally I'd be looking at battens/galvanised top hats and a aquapanel style board with and acrylic render system I would not accept the remove and replace like for like solution the insurer is suggesting.

makeorbrake · 18-01-2017 06:25PM

Just an update on this. I've spent an age trading correspondence back and forth with the insurer. They dismissed the alternative proposal that I put forward. I then reverted to consideration of the remediation plan that they came back with. I've asked queries on same before I will commit to signing off on that plan.

Key amongst those are the following;

1. I've asked them to confirm if the outer (render) layer will be impermeable to water ingress. They repeatedly avoided answering the question claiming relevance (!) - but now, they have come back with the following;

"With full fill cavities, there are many capillary tracks available for moisture to pass into the property. Accordingly it is imperative that the exterior rendering is watertight and maintained that way by the property owner throughout its service life. Our proposed external render system is the best and most appropriate for this dwelling. Lack of maintenance is exacerbating this situation."

They accepted liability in the first instance without a mere mention of 'lack of maintenance'. They started down this track AFTER the fact (once I went down the road of insisting that they answer the queries I put to them so that I could make an informed decision on their remediation plan). I clarified at that stage that due to the unusual nature of the cracks, I wasn't going to simply fill them in - until I could ascertain the nature of the defect. I outlined that others in the estate had done this and repainted also - only for the same horizontal cracks to re-emerge.

Furthermore, to my assertion that in addition that water is being carried across the cavity via the bonded bead cavity infill, I'm also claiming that this is also the case when it comes to what have been found to be improperly positioned (sloped inwards to carry water inwards) mortar snotted wall ties....(this was pointed out to them on-site by the engineer that I had engaged at that time - but they continually refuse to acknowledge this - even though I have an audio record of everything that was stated at that site meeting) to which their answer is this;

"With full fill cavities, there are many capillary tracks available for moisture to pass into the property. Any argument in regard to the passage of water along a wall tie is immaterial to the overall construction of this dwelling. "

I want to sanity check the position I'm taking as opposed their position. Am I being unreasonable in what I claim?

What the hell do you have to do in Ireland to get an honest/fair/reasonable outcome from an insurer!? :-(

Metric Tensor · 18-01-2017 10:16PM

I can't remember what part of the country you are in OP but for much of the country bonded bead is considered appropriate for unrendered walls and the agrement certs say so.

If you are in this region then the corollary is that the bead itself would be weather proof even if there was no render and hence the leak is caused by faulty installation of some items of the wall - as you've said all along! (The render having "failed" is beside the point in this case - in my view) Of course if you're in a high driving rain area then the above is not as clear cut.

This multiple flow paths talk sounds very much like someone with some technical knowledge throwing out as much crap as they can come up with to wriggle their way out of it. It's pretty much saying that all full fill cavities rely on the external render for water proofing. This is wrong and the person who wrote that knows it.

Although external render is usually water proof it is not guaranteed to be so and any construction method that relies on the external render alone for water proofing is in trouble from the start *

*The fact that this calls in to question the suitability for use of full fill pumped cavity insulation in swathes of the country is a debate for a different day!

makeorbrake · 18-01-2017 10:38PM

Metric Tensor wrote: »

I can't remember what part of the country you are in OP but for much of the country bonded bead is considered appropriate for unrendered walls and the agrement certs say so.

If you are in this region then the corollary is that the bead itself would be weather proof even if there was no render and hence the leak is caused by faulty installation of some items of the wall - as you've said all along! (The render having "failed" is beside the point in this case - in my view) Of course if you're in a high driving rain area then the above is not as clear cut.

I'm in the West of Ireland - in an area of driving rain - as per multiple agrement certificates for bonded bead (I asked them to supply the specific agrement cert. for this particular variety of bonded bead months and months ago but of course, they never responded with that).
All of those certs say its ok to use bonded bead in such areas PROVIDED the dwelling is rendered. However, that infers that the dwelling is rendered to a level by which it will not be defective and not alllow the infiltration of water.

Metric Tensor wrote: »

This multiple flow paths talk sounds very much like someone with some technical knowledge throwing out as much crap as they can come up with to wriggle their way out of it.

Yes, that's how I'm reading it. They keep saying that the wall ties are fulfilling their structural purpose - even though I've clarified that I'm not challenging or querying the primary purpose of the wall ties. I'm querying them on the basis that as they are poorly positioned (with an inversion inwards - and are mortar snotted, then they are providing a bridge for the transmission of water from outside to inside - alongside the bonded bead which is doing likewise (as the outer rendered layer is compromised).

They simply want to apply the very same rendered finish. I don't want to end up in exactly the same position as before - by which stage they wash their hands of it and I'm left high and dry. Their most recent suggestion is that this rendered layer will be watertight provided it's maintained!

makeorbrake · 18-01-2017 11:31PM

I asked them if what they were proposing (exactly the same as the current wall build up - without removing the compromised/wet bonded bead in-fill) would lock moisture into the wall - thus causing more issues. They came back with this;

"[our engineers] have advised this is not correct, the beaded insulation is hydrophobic. Moisture is present around some of the beading but their use of dehumidifiers and stripping of the internal plasterboard will deal with any moisture present. Strategic core holes to facilitate the complete removal of such moisture will be used as required. "

They say they will carry out the works over 4-6 weeks. Can the above be assumed to be correct? Is 4-6 weeks long enough?

makeorbrake · 03-05-2017 05:40PM

I'm making grinding, begrudging progress here. However, they still won't relent on certain aspects. I had hoped we were only a matter of a couple of weeks away from winding this up - but we're on the precipice of taking the full legal route given their holdback on a couple of items (which to me are no-brainers). One question...

Should a structural insurer have complete documentation as to the specification of the dwelling(s) that they decide to insure? I'm thinking specifically in terms of Agrement Certs for the bonded bead cavity fill and documentation as regards the contractor that carried out the work? They say they have neither and point me towards my 'local authority' in sourcing such documentation(!).

Does that sound logical?

Metric Tensor · 04-05-2017 12:20AM

In my opinion it is exceedingly unlikely that the local authority would have any such information.

Even in the modern era of BCARs the chances of that being in file are 50/50 at best I'd imagine for a non opt out project.

In theory you should have gotten a safety file with the house. This would be the best place to look if you got one. Otherwise it's construction drawings and specs from the original architect or builder.

Your question about whether the insurer should have it or not is a good one! ;-)

makeorbrake · 14-05-2017 04:48PM

No specific update on my own particular situation. It rumbles on. It may be wrapped up in a couple of weeks - or for all I know, it may ramble on for another couple of years (has been 2 years of squabbling so far). Neither of these scenarios are within my control - that's up to the insurer. Bottom line - they can step up and take responsibility or hold back on their obligations and we will continue on to the bitter end.

In the meantime, I noticed this article and thought it worthy of mention.

LINKY

No rocket science here. For those of you in the trade and more knowledgeable on the subject, you'll yawn your way through that piece. Even for regular folk (not working in any related trade or profession), there's nothing revolutionary or new here. It's common knowledge that 'muck' was built in the 'Tiger era. However, what it does offer is a prompt or reminder.

It's a reminder that most likely comes too late for many. However, if you took possession of your home towards the tail end of that building frenzy (and I guess '07-'08 is the tail end), you may still have a structural guarantee applicable to your home. I'd strongly advise you to take stock of what you have on your hands. Are there any deficiencies in the construction of your property? Has anything appeared that has stoked your curiosity - even if considered otherwise benign? Like me (prior to the outset of this saga), you may have little interest in construction detailing but it might be very worthy of consideration. What I've experienced started out very subtly - and didn't (at first) seem like anything that shouldn't happen with a build within it's first 10 years of existence. However, what seemed benign has developed into a major structural defect - and one that has already been conceded to take a lot of resources to remediate (and more still once I've finally proven beyond doubt the outstanding aspects that the other party are holding out on).

People lead busy lives and you may not have time to get round to something that may not seem relevant right now or may not be a priority. However, that window is closing for the remainder of the Celtic Tiger era builds. If you have an issue of concern on a dwelling that was signed off on - mid '07 onwards, get it checked out today. At the very least talk to someone in the trade or better still, shell out a few quid to get a professional assessment carried out - for your own peace of mind. Once that 10 year marker passes, the insurer is off the hook.

Don't allow yourself to be a victim of bad building practice. It's only in the tail end of this 10 year period that the hidden atrocities of Celtic Tiger Era building practices are surfacing. The next few years will reveal much more with regard to those builds. By that stage, the owners of such properties will have to face in to the costs of addressing something that was not of their making. When you consider that those that took ownership at the peak of the boom already face a lifetimes worth of unnecessary (bubble) debt, any such structural issues will just be the double whammy.

As for my own scenario, the next 2 weeks will tell a lot. Either this gets wrapped up fairly swift-ish or otherwise, we go the long(er) way round. These are not circumstances that are within my control. However what is within my control is my commitment to pursue this matter to it's full and entire extent. The actions of others in this matter have been cynical and meant to frustrate me and get me to throw in the towel. All they've served to do with each such attempt is motivate me further to see this through to a just and equitable outcome....and that's precisely my intention.

antiskeptic · 15-05-2017 11:46PM

makeorbrake wrote: »

No specific update on my own particular situation. It rumbles on. It may be wrapped up in a couple of weeks - or for all I know, it may ramble on for another couple of years (has been 2 years of squabbling so far). Neither of these scenarios are within my control - that's up to the insurer. Bottom line - they can step up and take responsibility or hold back on their obligations and we will continue on to the bitter end.

In the meantime, I noticed this article and thought it worthy of mention.

LINKY

No rocket science here. For those of you in the trade and more knowledgeable on the subject, you'll yawn your way through that piece. Even for regular folk (not working in any related trade or profession), there's nothing revolutionary or new here. It's common knowledge that 'muck' was built in the 'Tiger era. However, what it does offer is a prompt or reminder.

It's a reminder that most likely comes too late for many. However, if you took possession of your home towards the tail end of that building frenzy (and I guess '07-'08 is the tail end), you may still have a structural guarantee applicable to your home. I'd strongly advise you to take stock of what you have on your hands. Are there any deficiencies in the construction of your property? Has anything appeared that has stoked your curiosity - even if considered otherwise benign? Like me (prior to the outset of this saga), you may have little interest in construction detailing but it might be very worthy of consideration. What I've experienced started out very subtly - and didn't (at first) seem like anything that shouldn't happen with a build within it's first 10 years of existence. However, what seemed benign has developed into a major structural defect - and one that has already been conceded to take a lot of resources to remediate (and more still once I've finally proven beyond doubt the outstanding aspects that the other party are holding out on).

People lead busy lives and you may not have time to get round to something that may not seem relevant right now or may not be a priority. However, that window is closing for the remainder of the Celtic Tiger era builds. If you have an issue of concern on a dwelling that was signed off on - mid '07 onwards, get it checked out today. At the very least talk to someone in the trade or better still, shell out a few quid to get a professional assessment carried out - for your own peace of mind. Once that 10 year marker passes, the insurer is off the hook.

Don't allow yourself to be a victim of bad building practice. It's only in the tail end of this 10 year period that the hidden atrocities of Celtic Tiger Era building practices are surfacing. The next few years will reveal much more with regard to those builds. By that stage, the owners of such properties will have to face in to the costs of addressing something that was not of their making. When you consider that those that took ownership at the peak of the boom already face a lifetimes worth of unnecessary (bubble) debt, any such structural issues will just be the double whammy.

As for my own scenario, the next 2 weeks will tell a lot. Either this gets wrapped up fairly swift-ish or otherwise, we go the long(er) way round. These are not circumstances that are within my control. However what is within my control is my commitment to pursue this matter to it's full and entire extent. The actions of others in this matter have been cynical and meant to frustrate me and get me to throw in the towel. All they've served to do with each such attempt is motivate me further to see this through to a just and equitable outcome....and that's precisely my intention.

I've followed your travails on and off. Hat's off for the perseverance.

I'd a small chimney fire a few years back and quickly found out how the insurance game runs: the aim is to induce claims fatigue. They bicker and resist and stonewall and dodge in order to grind you down and have you settle for less.

What could have been settled quickly and cheaply turned into a 3 month out of house slog and a claim level fought for that would cover my costs and compensate me for the time and stress spent fighting the insurance company for those costs. Although I came out on top in the end, it was a fight I wouldn't want to engage in again.

You may be already aware but a word of warning on temporary accommodation costs. Up in Dublin, these run at approx 3 times the normal rental rate (normal being a 6 month or annual lease) - if you can get it.

Read the terms and conditions carefully on this front if your moving out and find out what happens if the projected time you're out for runs on - is it you who pays?

Best of luck in the hope you're approaching an end to it all.

makeorbrake · 16-05-2017 09:09AM

antiskeptic wrote: »

how the insurance game runs: the aim is to induce claims fatigue.

In that handful of words, you've captured the essence of their game.

antiskeptic wrote: »

You may be already aware but a word of warning on temporary accommodation costs. Up in Dublin, these run at approx 3 times the normal rental rate (normal being a 6 month or annual lease) - if you can get it. Read the terms and conditions carefully on this front if your moving out and find out what happens if the projected time you're out for runs on - is it you who pays?

A good point and one that I was curious to see how they would deal with it. I live in a tumbleweed regional town out West and even here, rental can be difficult to get a hold of - let alone temporary accommodation. I knew this would be a difficulty so they've had to price on the basis of a factor of 2.5x times the duration of the time they had estimated would be needed to complete the works. i.e. there's no way they could secure an equivalent property over a shorter timescale.

antiskeptic wrote: »

Best of luck in the hope you're approaching an end to it all.

Another significant step taken yesterday. Either it's the beginning of the end or the end of the beginning. Totally up to them whether it's the former or the latter - will be staying the course either way.

makeorbrake · 03-06-2017 05:13AM

Process delayed due to red tape I won't bore you with. I'm using that time to continue to do my due diligence and figure out any other items that may be at play.

Here are a few shots of the inside blockwork of the apex of the gable from the attic space;

Pics

Here's a reminder of what that section looks like from outside;

Pic

Is there any significance in the change of colour of the mortar? Naturally, it's bone dry to the touch - but then given recent temperatures over the past few weeks, it would have been baking in there. I guess I should have gone up there in the middle of winter.

Your feedback welcome if there's anything relevant in play here. If there's not, please ignore. This may seem a bit drawn out (I've lived it - so I know it is.....should have been settled in a matter of weeks as far as I'm concerned but that's another story) - but just want to cover all my bases before I'm drawn into signing off on a deal without ANY comeback.

tabby aspreme · 03-06-2017 07:39AM

There appears to be horizontal cracks either side of , and above the window, because the cracks are so straight they are probably going through the block work joints

Molzer2 · 05-01-2021 11:50PM

Hi Op, just read your thread and found it fascinating. Any conclusion?

Identifying root cause of water ingress from outer to inner leaf - cavity wall

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