thesis on external insulation (ewi)

FarAdr

I weas just wondering if anyone could help me, I'm doing a thesis on external insulation for college. Many companies haven't got back to me as they don't like my questions as, I do have to find the faults in many systems. I am trying to find the best solution, but i know that mould growth can be a problem depandant on the facade.. breathability is another issue, cracking in the plaster has arisen also especially after the harsh cold december.

Maybe some of ye could tell me of your experiences and what you thought of each system?
Also, if there was someone that was thinking of doing it, I would like to do a thermal imaging test if possible on the house before and after to see the actual difference.
Detail can be a major issue, as many cowboys '****' it on the wall and away. soffits shoud be removed and extreme detail has to be taken around the windows... especially the cills!!

Any help would be greatly appreciated.
Also, I am from Cavan and studying in Dublin. Not a young student either, so I won't wreck your head.
Thanks.

TiNcAn

I was wondering if you could answer me a few questions. I have been searching the internet for quite some time now to come up with some reliable figures for the lifetime of an external insulation systems, particularly in Irish weather conditions. So far I have not have had nay luck so if there is anything you could share it would be greatly appreciated.

I would also invite you to take some findings before and after if I choose to pursue external insulation.

Much appreciated.

Supertech

Cost is an issue aswell FarAdr. I looked at using it on a (very) small project recently which was to be grant assisted - a refurbishment of a small club house. EWI was coming in at about 3.5 times the cost of internal dry-lining on that particular job. Because the budget was so tight,and because there was other works which absolutely had to be carried out, we had no option but to go for the internal solution despite the obvious practical advantages of EWI over dry-lining. Agree with you regarding the detail - all existing junctions need to be examined when considering use of EWI aswell, but in fairness, as with most systems, once due thought is given to their application, acceptable solutions can be found in most instances.

With regard to to your thesis, have a look at some of the NSAI Certified systems and check out the specific stipulations attached to the certs. this will give you a pointer to the areas which need specific attention with each system.

agrostar

TiNcAn wrote: »

I was wondering if you could answer me a few questions. I have been searching the internet for quite some time now to come up with some reliable figures for the lifetime of an external insulation systems, particularly in Irish weather conditions. So far I have not have had nay luck so if there is anything you could share it would be greatly appreciated.

I would also invite you to take some findings before and after if I choose to pursue external insulation.

Much appreciated.

+1 with your concerns about the lifetime of ewi systems, i am currently in the planning process and hopefully with a bit of luck hope to be building in the summer. I was hopeing to find out important information about lifetime and performance of ewi but i cant find it anywhere

sydthebeat

agrostar wrote: »

+1 with your concerns about the lifetime of ewi systems, i am currently in the planning process and hopefully with a bit of luck hope to be building in the summer. I was hopeing to find out important information about lifetime and performance of ewi but i cant find it anywhere

check the nasi certification for external insulation here
You really need to read each individual certification and observe the different "durability" assessments (there are generally in section 4.8 of the certs)

some have 30 year durability, some have 60 years.... some have others.

also find out what warranties are available with each system... and find out what will happen if the particular company goes out of business in the lifetime of the warranty.

TiNcAn

I have read through the suppliers documentation but am still not convinced. It states that;

The assessment indicates that the system should
remain effective for at least 30 years, providing
that it is designed, installed and maintained in
accordance with this Certificate.

which would suggest that it would last for at least 30 years. However the guarantee offered only lasts 10 years.

This form of insulation has been around for quite some time especially in places such as Germany since the 1980s. It would be very helpful to have some first hand experiences with people who have external insulation for at least 2 years. Granted that there have been developments in the systems used but it would still be of great benefit.

Sorry for the hijacking of the thread, just trying to clear up some of my concerns which I am having.

sydthebeat

i dont think your hijacking, i think your concerns are pertinent.

other EWI certs are for 60 years.

Im not too concerned that the guarantee only generally last 30% of the proposed durability period. When i buy a car i might get a 3 or 5 year warantee but id expect it to last a lot longer than that.. .subject to proper maintanence of course... same with building methods.

TiNcAn

Upon going through the list of NSAI certified EWI suppliers I have found only three brands that offer a effective life expectancy of at least 60 years. These include 2 models from weber.therm and 1 from StoTherm. Every other model only offer at least 30 years.

This would lead me to believe that these models are more durable and reliable brands of EWI. They also offer longer guarantees than most of their competitors with weber.therm offering 15 years and StoTherm offering 20 years.

I am wondering would it be accurate to expect a full 60 years lifetime from a quality installed either of these two brands. The difficulty arises in that there is only laboratory data to back this data up and no real world tests as they have not been around for that long.

It would also be of great benefit if someone could PM the details of a few contractors that supply these brands. I will have look myself but help would be appreciated.

sas

As far as I know:

The certs offering 30 years are the ones that were certified for retrofit only, not new build. This is where most of the work currently is so you can understand why it's the type of approval that companies apply for. NSAI certification is extremely expensive.

The 60 years applys to new build.

I can't say what but I can guess. On a new build everything should be stable and good. There is less risk of something else failing and affecting the EWI.

If you fix EWI to a wall that has been dashed for 20 years, there is always a risk that the dashing could fail over time and bring the EWI with it.

As I understand it, the materails for new build and retrofit are identical, so it has to come down to the substrate.

STO offer a 20 year warranty only if you pay a hefty premium for it afail i.e. it's an extended warranty, not the standard one.

sas

TiNcAn wrote: »

I am wondering would it be accurate to expect a full 60 years lifetime from a quality installed either of these two brands. The difficulty arises in that there is only laboratory data to back this data up and no real world tests as they have not been around for that long.

NSAI certification is not a warranty, so no, it's not accurate to expect a full 60 years lifetime from a quality installer of those brands.

You'll also find that the warranties are massively complicated and ultimately you'd be hard pressed to prove that the system failed and not something else.

FarAdr

Supertech wrote: »

Cost is an issue aswell FarAdr. I looked at using it on a (very) small project recently which was to be grant assisted - a refurbishment of a small club house. EWI was coming in at about 3.5 times the cost of internal dry-lining on that particular job. Because the budget was so tight,and because there was other works which absolutely had to be carried out, we had no option but to go for the internal solution despite the obvious practical advantages of EWI over dry-lining. Agree with you regarding the detail - all existing junctions need to be examined when considering use of EWI aswell, but in fairness, as with most systems, once due thought is given to their application, acceptable solutions can be found in most instances.
.

Yeah, cost does seem to be a big issue, but some people have no alternative but to insulate externally as the work which is required internally after dry lining is excessive of that externally.
What I mean is that you may have to move out of your home, there are decoration costs and storage, the removal of a kitchen etc and the reinstalling of all electrical appliances/sockets etc..and then theres the fact that your losing square footage of your living space, which in many parts of the country mainly Dublin is how your home is valued.
I suppose with regards a clubroom these problems aren't so much an issue, as there is limited services and decoration but as the saying goes different horses for different courses.
Also with drylining there can be problems also which take a long time to arise. Seemily bad insulation options or approaches to insulating a home can cause mould growth which in turn causes asthma. As the insulation is stopping vapour penetrating the fabric, it can cause damp spots within the drylining, particularly with corners and floor junctions etc. Then theres the issue of cold bridging if this is your thing... and external insulation when applied in the correct manner prevents this.. wrapping your home in a blanket.

FarAdr

i dont think your hijacking, i think your concerns are pertinent..[/QUOTE]

God, no all information with regards this subject is greatly appreciated, as I said I want to hear everything that people know and have experienced with the product.
At first I didn't realise that there were so many products and alternatives for EWI, but there is so much to be looked at.
Firstly, know what your building is constructed with, and your foundation type and whether you have dpcs etc. There is a serious lack of investigation when people insulate a house. For instance, an old stone wall was built from rubble, bricks and whatever could be thrown in along with lime perhaps. This is where I have found a serious issue. these walls were built to breathe, that it how they dry out and this is why lime renders are used on such buildings.They also move with the seasons and therefore anything rigid is a big no no. What they are insulated with has to be flexible and move with the house, and be able to breathe and let the wall dry out. Breathability is the main concern when retrofitting an old house I have learned.
Thats just touching that topic.. I still have to investigate it further.
If its a sustainable you want to take, there are many options; woodfibre, rockwool, sheeps wool, hempcrete to name but a few... where these seem to be lacking is resistance, they need a greater depth to achieve the same results as the chemical options such as eps xps.
What I have found is that proper detailing of these cannot be compromised, and make sure you have someone with the knowhow or qualification to show you how to achieve the best result... including removing the soffit and insulating above to the rafters to achieve a tight seal of insulation. If possibe, and I know that it has extra cost, remove the windows and bring them in line with the insulation in some way or other.. also get the sill cut in line with the blockwork.. this adds a greater insulation value and prevents the risk of a cold bridge or cracking at the sill.
I could go on but I'm sure this is long enough, however you may need to look at insulating below the ground in some circumstances also.

sas

sas wrote: »

As far as I know:

The certs offering 30 years are the ones that were certified for retrofit only, not new build. This is where most of the work currently is so you can understand why it's the type of approval that companies apply for. NSAI certification is extremely expensive.

The 60 years applys to new build.

.

Turns out this was incorrect.

I contacted NSAI and asked them because this is particularly relevant to me right now.

You will notice that the certs with 60years were some of the first EWI ones issued. Basically, the practise back then (and I think it was a requirement which has since been dropped) was for systems for new build to have a 60 year life expectancy. The problem with that is that this 60 years is outlandish when compared to everywhere else in Europe and we were put under pressure.

Most of the NSAI certs are based on ETAs which have a 25 year period specified on them. It's alot easier for a company to get NSAI certification of 30 years when a ETA for 25 is already in place. It actually sounded very "finger in the air" type testing to get from 25 to 30 years. I was told that companys are encouraged to go for the 30 year option if an ETA exists for the system in question.

Once a system is in use for a period of time, they may then be able to apply to get from 30 years to 60 years.

For the earlier certs (60 years) they (NSAI) sometimes recommended a slightly thicker render for example. By the sounds of it however, there wasn't alot of testing done.

I've always been very dubious about agrement certs. I haven't changed that opinion after my conversation with them.

Rockfall

Some inaccuracies there I'm afraid.

NSAI Agrément certified external insulation systems, as well as other building systems, for a 60 year design life as this was a requirement of the DoEHLG to obtain a Floor Area Compliance Certificate for a dwelling in order for it to be eligible for the first time buyers grant. This requirement has not been dropped due to pressure from Europe, but actually as a result of the first time buyers grant being dropped in the recent budget.

ETAs certify for a design life of anything between 10 and 30 years. In order for NSAI Agrément to certify a design life of 30 years for a system, they have to visit sites where the product has been used for a considerable period of time to obtain info on history of use, maintenance requirements etc.

60 year certified systems always have a double thickness of render compared to 30 year systems, unless the manufacturer in question insists on an equally thick render for a retrofit 30 year system.

sas

Balls, I'm having a shocking run on this thread

Rockfall wrote: »

Some inaccuracies there I'm afraid.
NSAI Agrément certified external insulation systems, as well as other building systems, for a 60 year design life as this was a requirement of the DoEHLG to obtain a Floor Area Compliance Certificate for a dwelling in order for it to be eligible for the first time buyers grant. This requirement has not been dropped due to pressure from Europe, but actually as a result of the first time buyers grant being dropped in the recent budget.

Cool. I most definitely was not told this by this NSAI however.

Rockfall wrote: »

ETAs certify for a design life of anything between 10 and 30 years. In order for NSAI Agrément to certify a design life of 30 years for a system, they have to visit sites where the product has been used for a considerable period of time to obtain info on history of use, maintenance requirements etc.

There was no mention of site visits etc. when I asked about going from 25 to 30 years. I was left with the impression that basically 25 years or 30 years, there's not much in it so we (NSAI) won't be overly worried given that the testing had already been done by someone else.

Thanks for clarifying.

biddyearly

Hi There

I did a thesis on Insulated Concrete Formwork which would be kinda similar to external Insulation, Afterwards i worked as a site Engineer on an ICF Development. We encountered problems with this system in terms of cracking etc. If i can be of any help pm me.

BryanF

biddyearly wrote: »

Hi There

I did a thesis on Insulated Concrete Formwork which would be kinda similar to external Insulation, Afterwards i worked as a site Engineer on an ICF Development. We encountered problems with this system in terms of cracking etc. If i can be of any help pm me.

Hi,
tell us more please.
where and in what situations was the cracking etc?

sas

biddyearly wrote: »

Hi There

I did a thesis on Insulated Concrete Formwork which would be kinda similar to external Insulation, Afterwards i worked as a site Engineer on an ICF Development. We encountered problems with this system in terms of cracking etc. If i can be of any help pm me.

This isn't by any chance the development in Limerick (I think, or maybe Ennis) where the BRE did an investigation and as I recall ultimately it can down to the plastering contractor having made a mess of it.

I.e. system good, application bad.

Rockfall

sas wrote: »

There was no mention of site visits etc. when I asked about going from 25 to 30 years. I was left with the impression that basically 25 years or 30 years, there's not much in it so we (NSAI) won't be overly worried given that the testing had already been done by someone else.

Thanks for clarifying.

No problem. I'd love to know who you were talking to in NSAI as they didnt give you the right info at all, and actually did a huge disservice to NSAI Agrément as a result.

badger81

ah great, i thought icf was 'the' thing. i've since had my mind changed to external insulation and nowi find myself doubting this method,
i swear this decision is almost as difficult as dealing with offaly co co

badger pullin his hair out

FarAdr

its actually ridiculous the amount of stuff that is out there. As I have stated, im trying to do a thesis on it and every day something new is found out and considerations which should be taken into account. just with the render itself, we discussed that if a child or adult even is puckin a sliotar at the wall, its small hard and fierce pressure behind it, will it damage the render and let water seep through? its a case that might not be taught of, but it happens, and then theres hanging flower baskets or something of the like, this creates holes which in turn lets water penetrate.
Should a cavity be left behind to let water out if it does get in? and if you do leave a cavity behind, then your insulated render won't be as strong as its not on a solid substrate (wall) and can buckle and bend easier...
There really is so much to consider, but don't believe all the bull*hit that company sales reps tell ya, cos obviously they are getting a cut and will promote their product and demote others.
Hope ya come to a conclusion anyway!!!

badger81

FarAdr wrote: »

its actually ridiculous the amount of stuff that is out there. As I have stated, im trying to do a thesis on it and every day something new is found out and considerations which should be taken into account. just with the render itself, we discussed that if a child or adult even is puckin a sliotar at the wall, its small hard and fierce pressure behind it, will it damage the render and let water seep through? its a case that might not be taught of, but it happens, and then theres hanging flower baskets or something of the like, this creates holes which in turn lets water penetrate.
Should a cavity be left behind to let water out if it does get in? and if you do leave a cavity behind, then your insulated render won't be as strong as its not on a solid substrate (wall) and can buckle and bend easier...
There really is so much to consider, but don't believe all the bull*hit that company sales reps tell ya, cos obviously they are getting a cut and will promote their product and demote others.
Hope ya come to a conclusion anyway!!!

I had not even thought of some of those things!!!!
Ah crap I give up......... Beaten by a house in my head

agrostar

Hey FarAdr hows the Thesis coming along?

I was talking to an architect and he was saying that the EWI may be prone to rodent attack... Dont no if this problem has been highlighted to you before or if it is even an issue........... I must investigate further into this issue myself because if i was to use EWI i dont think id care for rats to be tunneling into the insulation.:(:(

sas

badger81 wrote: »

I had not even thought of some of those things!!!!
Ah crap I give up......... Beaten by a house in my head

FarAdr wrote: »

its actually ridiculous the amount of stuff that is out there. As I have stated, im trying to do a thesis on it and every day something new is found out and considerations which should be taken into account. just with the render itself, we discussed that if a child or adult even is puckin a sliotar at the wall, its small hard and fierce pressure behind it, will it damage the render and let water seep through? its a case that might not be taught of, but it happens, and then theres hanging flower baskets or something of the like, this creates holes which in turn lets water penetrate.
Should a cavity be left behind to let water out if it does get in? and if you do leave a cavity behind, then your insulated render won't be as strong as its not on a solid substrate (wall) and can buckle and bend easier...
There really is so much to consider, but don't believe all the bull*hit that company sales reps tell ya, cos obviously they are getting a cut and will promote their product and demote others.
Hope ya come to a conclusion anyway!!!

Couple of things to keep in mind.

An EWI system is soft relative to a typical block wall. Anything that is hit against it will have alot of the energy taken out of it and it won't return with any momemtum. So although the initial strike could cause damage, the likelihood of it being multiple strikes is lessened. It's basically the same as kicking a "flat" ball against a wall. Not too many kids will do that for very long.

Nothing of any meaningful weight should be hung off EWI. So hanging baskets or satellite dishes should be mounted elsewhere.

You suggested leaving a cavity in the system? Where do you suggest the cavity be left? I don't believe it was clear from your post.

As regards minor damage and water ingress. In the case of EPS insulation, I don't see any cause for concern. EPS when submerged absorbs little water. No amount of driving rain will simulate being submerged in my opinion. So you would have time to identify and repair any such damage. In the insulation materials being used water absorption may be more of an issue but I don't know enough about them to comment.

This is my take on it. EWI systems have been used successfully in european countries for decades. Irish companies did not invent these systems, they are not new. Do they not have sporty children, rain or rodents in other parts of europe. I believe alot of "concerns" being thrown around are by poorly educated building professionals who'd rather keep doing what they've always done than adapt to something new. The same people would likely recommend drylining over EWI.

Disclaimer: I'm building my own home and will be using EWI on it. Starting in 4 weeks all going well. I'm not a construction professional and my opinions are just that.

PaulieBoy

sas wrote: »

This is my take on it. EWI systems have been used successfully in european countries for decades.

Tends to be a dryer climate than our constantly damp climate. That must be factored in. Constant damp will break down pretty much anything.
All I have seen turns me right off such systems. Workmanship is dire! Pipes, gutters etc all buried behind the insulation all just sitting there waiting to cause problems, I saw an outdoor tap fitting buried behind the insulation, tap leaking! No way to fix it without doing major damage to the insulation. Mad stuff. The pricing is such that to make a living costs are being cut, I know for a fact that one supplier told potential fitters to go easy on the adhesive! It's expensive and margins are tight. It's the great new frontier for the cowboy.
I would not touch it. Just my two cents.

FarAdr

sas wrote: »

Couple of things to keep in mind.

An EWI system is soft relative to a typical block wall. Anything that is hit against it will have alot of the energy taken out of it and it won't return with any momemtum. So although the initial strike could cause damage, the likelihood of it being multiple strikes is lessened. It's basically the same as kicking a "flat" ball against a wall. Not too many kids will do that for very long.

Nothing of any meaningful weight should be hung off EWI. So hanging baskets or satellite dishes should be mounted elsewhere.

You suggested leaving a cavity in the system? Where do you suggest the cavity be left? I don't believe it was clear from your post.

As regards minor damage and water ingress. In the case of EPS insulation, I don't see any cause for concern. EPS when submerged absorbs little water. No amount of driving rain will simulate being submerged in my opinion. So you would have time to identify and repair any such damage. In the insulation materials being used water absorption may be more of an issue but I don't know enough about them to comment.

This is my take on it. EWI systems have been used successfully in european countries for decades. Irish companies did not invent these systems, they are not new. Do they not have sporty children, rain or rodents in other parts of europe. I believe alot of "concerns" being thrown around are by poorly educated building professionals who'd rather keep doing what they've always done than adapt to something new. The same people would likely recommend drylining over EWI.

Disclaimer: I'm building my own home and will be using EWI on it. Starting in 4 weeks all going well. I'm not a construction professional and my opinions are just that.

Yeah, your right that it is around years, in Ireland since 1966 in fact, but there are considerations that should be accounted for. Things that people don't even think about. The detailing around windows and doors, even below dpc level and at soffit level being most important.
I'm not trying to put people off using it, I wouldn't do that, sure every product needs taught, and every product will have faults.
With regards water ingress, that depends on what you use, sure theres wood fibre, rockwool batts, closed cell insulation such as phenolic. the first two will sag when wet and the third can warp and twist and soak up water. Its stated that if an insulation takes in 10% of its own weight in water, its performance will be reduced by 30%.
Its also to do with dew point within the wall, moisture within the wall which can come from the inside, and this in itself can cause problems and may often not be visible.
When it comes to cracking plaster etc, it is going to be softer, sure its not on a solid substrate, and is susceptible to cracking, and along with this, if its not correctly applied could even happen at board joints. Then theres the fact that most renders will be of a coloured nature, repairing these to the exact same colour will be problematic. I think theres a thing called freeze thaw that can affect to, have to look at it more.
A cavity may be left between the insulation and the wall possibly, just a small one. I seen a system that uses strips of 10mm eps to create a 10mm cavity for moisture etc, but again, dependant on what your applying to, and what your applying. I have also discussed with a professional putting the cavity behind the render, so you'd probably have a cementitious board or ply to fix the render to so its solid and then a cavity and your ewi. However, the problem here is making the cavity and do you fix your timber or whatever back to the wall, creating a cold bridge, which you are trying to eliminate? Also, with the render on the boards externally, is there need for movement joints.
There is more than you think, this is why I'm looking into it, and I myself am an Architectural Technologist, but back studying with the lack of opportunity out there.

FarAdr

(quote)Hey FarAdr hows the Thesis coming along?

I was talking to an architect and he was saying that the EWI may be prone to rodent attack... Dont no if this problem has been highlighted to you before or if it is even an issue........... I must investigate further into this issue myself because if i was to use EWI i dont think id care for rats to be tunneling into the insulation.

PaulieBoy wrote: »

Tends to be a dryer climate than our constantly damp climate. That must be factored in. Constant damp will break down pretty much anything.
All I have seen turns me right off such systems. Workmanship is dire! Pipes, gutters etc all buried behind the insulation all just sitting there waiting to cause problems, I saw an outdoor tap fitting buried behind the insulation, tap leaking! No way to fix it without doing major damage to the insulation. Mad stuff. The pricing is such that to make a living costs are being cut, I know for a fact that one supplier told potential fitters to go easy on the adhesive! It's expensive and margins are tight. It's the great new frontier for the cowboy.
I would not touch it. Just my two cents.

Thesis going ok so far, its just a matter of cutting down words at this stage and put in the most relevant information. I have to make an argument at the end of the day, then I have to do research myself.. thermal imaging and stuff.
Haven't came across the rodent thing as of yet, but I shall be looking into it, again could be useful. I think the problem ther though is how did the rats get at the insulation... I suppose below dpc would be the answer.. sure ya can't render the plinth to the foundation, or can ya...

Think paulieboy may have hit it there with regards climate, and we all know the cowboys (heaven knows i've even worked for a few in the good times) Thats another problem with the state, there isn't proper building standards authority. I know that in the North they have a rep comes out and visits the buildings at certain stages to check workmanship. Like getting your Architect to sign off the house is just a joke to be honest, There are some good ones out there but most see that it means more work and time out of making money. Some will sign off without even looking, sure you can't see behind a closed wall... sorry ranting here.

With regards climate though, and what works across Europe should work here, thats bulls**t. Timber cladding was seen as the future and sustainable here for the past ten years, with many buildings in Dublin and across the country being clad in untreated cedar and the likes... 'sure it'll age naturally'.. look at them buildings now, rotten, and cladding changes colour from the sun so the top of your cladding under the soffit for example is a different colour from the rest and each facade is different. Now the wood federation are looking at how to clad and writing books on what went wrong.. I was at a lecture with them last week by the way. Now they want to put it right and treat everything. This just proves that following Europe isn't always the way.
Also, in building or doing anything in the West of Ireland is even worse, its seen to have some of the worst weather conditions in Europe, and the dampest or moistest air... It is advised not to clad tall there.
I know thats a bit off the point but it may make some people think....

PaulieBoy

FarAdr wrote: »

Thesis going ok so far..

Good to hear!
You should consider going to one of the "training courses" offered by the suppliers, posing as a potential installer. It's the old "get in and out" as quick as you can to make money. The results are there to see for anybody with a keen eye. As noted "trainees" are told to use as little adhesive etc as possible as the price is now on the floor! Insulation is not supposed to get wet. I've seen houses being washed out of it with insulation exposed. Were blow heater used to dry them out before the finish was applied ? You know the answer to that !
The system is a "hack" to insulate a building, it may work if applied correctly in the appropriate setting. It's not something you would let a cowboy builder install in a damp climate.
I feel sorry for the honest people that are throwing their money away on this.
Totally off topic but our damp climate is totally wrong for timber frame houses for the exact same reason, bad detailing and constant attack will see premature wood decay in the frame. It's Ireland!

sas

PaulieBoy wrote: »

Tends to be a dryer climate than our constantly damp climate. That must be factored in. Constant damp will break down pretty much anything.
All I have seen turns me right off such systems. Workmanship is dire! Pipes, gutters etc all buried behind the insulation all just sitting there waiting to cause problems, I saw an outdoor tap fitting buried behind the insulation, tap leaking! No way to fix it without doing major damage to the insulation. Mad stuff. The pricing is such that to make a living costs are being cut, I know for a fact that one supplier told potential fitters to go easy on the adhesive! It's expensive and margins are tight. It's the great new frontier for the cowboy.
I would not touch it. Just my two cents.

The "our climate is different" argument is thrown around alot. I've not seen anyone produce the numbers to show the over all affect on building systems however. I don't dispute that we get alot of rain. We do get quite a bit of wind too and have a relatively mild climate which combined does contribute to the overall drying effect. If you've got something concrete on this please provide link as I'm sure the OP would find it useful for his thesis.

The rest of what you posted is about cowboy suppliers and cowboy builders. This applies across every system. There's companies going around pumping all sorts of stuff into cavities for next to nothing and home owners are only too glad to let them do it. I've no issue with pumped cavities as long as it's a material that is suitable for it. You get my point however.

sas

FarAdr wrote: »

but there are considerations that should be accounted for. Things that people don't even think about. The detailing around windows and doors, even below dpc level and at soffit level being most important.

By people who do you mean? I believe that there should be accountability for anything work that is carried out on a home. The detailing becomes the responsibility of the applicator and the home owner shouldn't have to worry about it. As with all systems, there are specific details (for openings as you've mentioned). The one that concerns me most with EWI systems is at door thresholds. I'm still not 100% sure how I'll detail this for my own home.

FarAdr wrote: »

With regards water ingress, that depends on what you use, sure theres wood fibre, rockwool batts, closed cell insulation such as phenolic. the first two will sag when wet and the third can warp and twist and soak up water. Its stated that if an insulation takes in 10% of its own weight in water, its performance will be reduced by 30%.

I personally don't like the render systems with wood fibre. My opinion on it is if you're using it on a TF, it needs a cavity. The phenolic one has been discussed widely on various forums since it was pulled from certain IAB certs. Quoting % in a sweeping manner like you did is very misleading. Every single insulant will be affected differently by water. However, in alot of cases the materials need to be standing in water to soak it up, driving rain isn't going to do it. This needs to be clear.

FarAdr wrote: »

Its also to do with dew point within the wall, moisture within the wall which can come from the inside, and this in itself can cause problems and may often not be visible.
When it comes to cracking plaster etc, it is going to be softer, sure its not on a solid substrate, and is susceptible to cracking, and along with this, if its not correctly applied could even happen at board joints. Then theres the fact that most renders will be of a coloured nature, repairing these to the exact same colour will be problematic. I think theres a thing called freeze thaw that can affect to, have to look at it more.

In an externally insulated masonry wall, the dewpoint will most likely be out in the insulation itself, which means a well installed vapour layer will prevent any issues. The renders are semi flexible so they can take a certain amount of movement. Repairing to match the existing colour is also a problem in drying dashing for example. However with that you don't have the option of repainting to bring everything back to a clean base again. It's perfectly possible to paint EWI systems.

FarAdr wrote: »

A cavity may be left between the insulation and the wall possibly, just a small one. I seen a system that uses strips of 10mm eps to create a 10mm cavity for moisture etc, but again, dependant on what your applying to, and what your applying. I have also discussed with a professional putting the cavity behind the render, so you'd probably have a cementitious board or ply to fix the render to so its solid and then a cavity and your ewi. However, the problem here is making the cavity and do you fix your timber or whatever back to the wall, creating a cold bridge, which you are trying to eliminate? Also, with the render on the boards externally, is there need for movement joints.

If you put a cavity between the insulation and the wall, the cavity will need to be ventilated assuming moisture will get to it. A ventilated cavity on the warm side of insulation renders the insulation pointless.

Assuming it was possible to mount a render board outside EWI in a thermal bridge free manner, no one would every do it because it would be simply too expensive. I researched such systems when I was considering TF and it was cost restrictive then before you factor in combining it with an EWI system.
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FarAdr wrote: »

There is more than you think, this is why I'm looking into it, and I myself am an Architectural Technologist, but back studying with the lack of opportunity out there.

How do you know how much I know

It's an interesting topic. The impression I have from reading your posts is that it's title will be "Why not to use EWI systems in Ireland". Am I close?

sas

FarAdr wrote: »

With regards climate though, and what works across Europe should work here, thats bulls**t.

I hope you can choose more elegant language to make your point in your thesis.

Alot of the points you put forward earlier I pointed out would be equally relevant elsewhere in Europe. Mechanical damage, rodents etc.

As regards the climate, as I said in an earlier response, I would like to see studies to back up the claims that these systems aren't suitable. I could point to NSAI certs that say they are.

If there is a problem with my home down the line, then I will be very vocal. I wouldn't like to see anyone get themselves in trouble, particularly with such an expensive system. I'll give Duncan a shout to take a look or have my favourite construction mag down for a look too.

Incidently if you'd like to take a look once the job gets underway in 4 - 6 weeks time drop me a pm.