Help please on insulation options

[Jeremy Harris]

4 minutes ago, NSS said:

And all the time we speak in what, to the vast majority of the population, is complete gobbledygook then that won't change. IMHO, if this forum really wants to encourage low energy homes to become the norm then it has to stop demanding a quantum leap to the Holy Grail (and scoffing at anything less) and recognise that a lot of people making small steps is better than a few scientists, academics and energy geeks fretting over minutia that means absolutely nothing to the masses.

A quick look through the posts made in the few weeks since this forum came into existence shows no evidence at all to support your view.  The majority of posts have been practical enquiries or advice, with not a single post I can find "demanding a quantum leap to the Holy Grail" and none "scoffing at anything less".  If you can prove otherwise, and that there is lack of balance here, then please highlight the specific post numbers to prove that your assertion is valid.

Sure I personally have a low tolerance for inaccuracy and downright misleading information being propagated by those who should know better.  I also happen to believe (along with a fairly large body of other people, including the AECB), that our building regs are both pretty poor and that, far more importantly, there is a lack of diligence in enforcing them.

However, I'm just one of a 150 or more members; some share views similar to mine, some don't.  Frankly it would worry me if things were otherwise. 

[NSS]

9 minutes ago, Oz07 said:

I do think you have a point. The old place used to be a good recourse for technical knowledge and practical advice. Over years it changed to a place where the focus was energy efficiency if that is the right term. 

To to be fair though I do respect the work which has gone into these passiv/nil energy projects. 

As do I, but I just wonder how many people only read the forum(s) rather than participate for fear of being made to look/feel a fool. Thankfully I've been a fool all my life so it's like water off of a duck's back.

[ProDave]

Interesting debate.

Yes a lot of people here think building a well insulated low energy house is a good idea. But I don't recall ever making anyone look like a fool for not agreeing.  I recall one discussion on the old place where the poster was adamant he wanted to do just enough to comply with regs and no more. Some of us suggested he could do better and it wouldn't cost much to build to a better standard. He was adamant he just wanted to do the minimum. I don't recall him ever being made to look a fool or feel unwelcome.I certainly hope he didn't feel that was the case.

It still amuses me that people will only buy an A+++ rated fridge, and then put it in a house with an EPC rating of F.

[PeterW]

29 minutes ago, NSS said:

And all the time we speak in what, to the vast majority of the population, is complete gobbledygook then that won't change. IMHO, if this forum really wants to encourage low energy homes to become the norm then it has to stop demanding a quantum leap to the Holy Grail (and scoffing at anything less) and recognise that a lot of people making small steps is better than a few scientists, academics and energy geeks fretting over minutia that means absolutely nothing to the masses.

I think there is a healthy balance on here on all topics - the energy efficiency / low energy / passiv(e) stuff always has polar views though !

UK building regs are appalling - full stop ! They are a minimum standard and don't encourage anything. Add to that the well known reports that volume house builders are cutting corners even with the minimum standards then it's not surprising the masses don't understand. 

Take this as an argument -

"Yes Mr Smith, our Balmoral new build has lots of energy saving features with uValues 10% better than most modern houses , annual bills 15% lower than the average property..."

So Joe Public (aka Mr Smith) thinks that's fab.! 

But it's not what it "could" be ..! Average energy bill for a 4 bed, let's say £1800 pa. This new house is only £1530. What if you said to Mr Smith that for £2k more insulation you could have 40% lower ..? Payback of 3-4 years ..??

You are then talking in numbers people understand, yet the masses sometimes don't get that anyway. The Green Deal is a classic example of this - saving energy just isn't exciting !

There are comparatively few parts of this forum that cover energy - it's got a lot of contributors who have a lot of experience on all areas, some have completed builds, some are building and some are yet to start. 

There are no daft or stupid questions - what some understand as they live and breath it daily is completely alien to others. One thing this forum (and ebuild) taught me was to ask the questions as it's certainly stopped me making mistakes that could have cost substantial amounts !

My next project can't be as efficiently built as we want as it has an existing structure - it won't stop me trying, but when cost is a factor too (like a lot of self builders) then there is compromise. I would much prefer to take an informed view by talking it through on here and learning from that, than bowling into the deep end and hoping ...!!

We can all help each other - it's about healthy debate and understanding !

[Nickfromwales]

34 minutes ago, NSS said:

And all the time we speak in what, to the vast majority of the population, is complete gobbledygook then that won't change. IMHO, if this forum really wants to encourage low energy homes to become the norm then it has to stop demanding a quantum leap to the Holy Grail (and scoffing at anything less) and recognise that a lot of people making small steps is better than a few scientists, academics and energy geeks fretting over minutia that means absolutely nothing to the masses.

The vast majority would be none the wiser if it wasn't for resources like this one. The gobbledygook that we 'apparently' speak of here is music to the ears of most, and is a refreshing change from the utter shit that most builders deliver to their unsuspecting customers whilst counting their cash out and walking away from another disgraceful example of how we used to live.  

If building an airtight and well insulated house in 2016 is a quantum leap to you, then where the hell have you been for the last few decades? Your comments are really out of touch with the ethos of what we strive for here, and to me seem quite far from the spirit of the community that enjoys, and appreciates, the quality, honesty and impartiality of the information freely available within. 

I too cordially invite you to make reference to any scoffing that has gone on, and I'll wager you can only recite comments which offer genuine contest or deliberate, well informed factual information to the contrary of anything that should receive such challenge. That information does indeed make resources, such as this forum, a holy grail of information for anyone who doesn't know different, or don't know that there is an alternative, and indeed better way of doing things. 

Why make small steps when you can make giant leaps in the same time, for the same effort, and with outstanding results? 

A thirst for knowledge is the reason I stayed here, and I am a better person for what I've learned so far, so I'll thank the geeks for their help so far, and ask, for one, that they continue to do so. 

Fwiw, I doubt if the masses agree with your POV. I don't, but it's your opinion and your entitled to it under the terms of free speech, which we are proud to observe here. 

[NSS]

21 minutes ago, JSHarris said:

A quick look through the posts made in the few weeks since this forum came into existence shows no evidence at all to support your view.  The majority of posts have been practical enquiries or advice, with not a single post I can find "demanding a quantum leap to the Holy Grail" and none "scoffing at anything less".  If you can prove otherwise, and that there is lack of balance here, then please highlight the specific post numbers to prove that your assertion is valid.

Sure I personally have a low tolerance for inaccuracy and downright misleading information being propagated by those who should know better.  I also happen to believe (along with a fairly large body of other people, including the AECB), that our building regs are both pretty poor and that, far more importantly, there is a lack of diligence in enforcing them.

However, I'm just one of a 150 or more members; some share views similar to mine, some don't.  Frankly it would worry me if things were otherwise. 

If you say so Jeremy. To be honest, when I saw that you were one of the team behind the new forum I seriously considered steering well clear, but I hoped it could be a broader church than ebuild had become. Apparently not so perhaps it's best that I just toddle off and leave you to it - then this is one fool you won't have to suffer (gladly or otherwise).

Feel free to delete any/all of my 16 posts, I'm sure nobody will miss them..

Good luck all.

[ProDave]

4 minutes ago, NSS said:

If you say so Jeremy. To be honest, when I saw that you were one of the team behind the new forum I seriously considered steering well clear, but I hoped it could be a broader church than ebuild had become. Apparently not so perhaps it's best that I just toddle off and leave you to it - then this is one fool you won't have to suffer (gladly or otherwise).

Feel free to delete any/all of my 16 posts, I'm sure nobody will miss them..

Good luck all.

Please don't toddle off. Nobody is suggesting you are a fool, your contributions here are welcome.  All this thread has suggested is that the claims of one particular type of insulation have in the past been over stated and we don't trust that type of insulation. And we suggested some alternatives that might be better. All without calling anybody a fool.

[Oz07]

I saw this coming the moment this thread was started...I bet op is wondering what they did wrong!

[Jeremy Harris]

If you take the time to analyse what happened on ebuild over the years (and I joined that forum in 2007, so do have a pretty good grasp on how it evolved) then there is a clear trend.  By 2010/11 ebuild was dead, there were virtually no posts being made and perhaps 5 or 6 active members.  Then, around 3 or 4 years ago, another forum had an upset, and a few members from there started posting on ebuild.  From that point on ebuild started to grow and become busier, although that growth was slow.

The curious thing is that the interest of members that joined after around 2012 did change.  More people seemed interested in building lower energy consumption self-builds, or renovating or restoring existing homes to better standards.  No one dictated this, no one made it happen by censoring out posts that didn't follow this general trend, it just developed naturally.  Personally I think a large part of that change was because people who joined that forum wanted to build themselves better homes, or they were interested in improving the homes they have.

No one person controls, or even influences, the direction a forum takes, unless it's one of the few forums that are heavily moderated to try and maintain a particular view.  Ebuild developed the way it did because that's the way the members shaped it.  The same will apply here, and it's already clear that this forum is different from ebuild in many ways.

NSS, if you happen to dislike me for some reason there isn't a thing I can do about it, other than feel regret.  I'd rather you just came out in the open and told me what your gripe is with me, because since this forum went live I've very deliberately taken a back seat and not done a single moderation task.  The direction this forum takes has not, and will not, be influenced by me, any more than it will be influenced by you, or any other member.

I'm at a complete loss to understand why you're seemingly so angry or upset.  You've not been criticised, made fun of, insulted, or belittled, as far as I can see, and if you had then I am sure that one or other of the moderators would have stepped in to put things straight.  If you feel you have, then point out the posts or parts of posts concerned, so they can be reviewed.  I'd not want to be part of any community where someone felt ostracised just for contributing fair comment.

[Nickfromwales]

Agreed. 

As I stated, freedom of speech and an entitlement to an opinion is a fundamental requirement to be able to engage, and be engaged, and thus learn from the subsequent exchanges. That's what I like about this particular community. 

Toddling off won't achieve anything tbh, and as your opinion is one that offers content and inspires debate I'd ask that you stick around and continue to participate accordingly. You may not be my cup of tea, and I may not be your cup of tea, but the world needs tea, that's for sure. 

Nobody here is perfect, but were quite happy to admit it .

[Nickfromwales]

33 minutes ago, Oz07 said:

I saw this coming the moment this thread was started...I bet op is wondering what they did wrong!

We can only hope the OP hasn't head for the hills , but to be fair, we are here to provide accurate information and we've done so. Such info is invaluable, and we can only hope that through the heated parts of this debate the best of what info is available has come through clearly, and has been of value. 

Now..........back to insulation we go   

 

[warby]

I believe the problem, that crept over from ebuild, is the tone of the language used. For example, using the term "Snake oil" humiliates a person that might have been duped,

There were too many opening contributions from Newbies" asking for them "to be treated gently", this indicates the fear people have to ask questions in the first place and they have drawn that conclusion from listening to the manner in  which questions are answered.

I have felt humiliated by responses in the past and I have thicker skin than most. I hope this warning from NSS is heeded on this new forum. Please no more personalisation against professions or products. It is not what is said it is the way it is said.

Jeremy please do not assume that people are making personal attacks against you. You have turned the comments from NSS as personal against you and last night you made it sound like I was making personal comment against you and nothing could be further from the truth, but you expressed it in a tone of conflict; simply not needed.

I thoroughly enjoy learning from this forum and share most of the points of view expressed but detest unnecessary conflict and criticism. I experience too much of that in my personal life and use the forum to escape from conflict.

[Stones]

And there in a nut shell is the problem for any forum, members trying to convey the right tone in written form.  It's not easy getting it right 100% of the time, and each of us will no doubt have caused offence or upset or been offended or upset ourselves in equal measure. We are after all, only human.

I was chatting to a fellow self builder earlier tonight, discussing amongst other things how frustrating it can be researching build techniques online and there being so many different ways to do things, and so many different points of view, as it's only natural for members to make comments which validate their own choices. 

I've taken the view that there is no such thing as a silly question, as it such questions which end up generating thought provoking discussion and from time to time innovative solutions. I'm on my sixth build and still learning...

[ToughButterCup]

Stones, Warby. Exactly.

[janedevon]

I haven't run anywhere!! I ran a euchre league on line for years and am well aware everyone has differing opionions, and different ways of expressing themselves, it's good to hear all sides of debate and as stated earlier some want to acheive the best spec and some want to do the bare minimum.

 

As for me I'm still not totally convinced as to what method I will choose to use, more research needed and as I get mor ,information I will come back here and ask questions, you are knowlegable people, I'm a baker I can help you on bakery products but as for house building I'm learning every day.

 

So its all good listening to everyones opinions offers a wide choice of options!!! 

[PeterW]

1 hour ago, janedevon said:

.... I ran a euchre league on line for years ....

A what...????! I'm not sure whether to google that or not ..!

[Nickfromwales]

Baker? 

2 bacon and cheese puffs and a split donut please  You've just validated your lifetime pass

 

[Jeremy Harris]

15 hours ago, warby said:

I believe the problem, that crept over from ebuild, is the tone of the language used. For example, using the term "Snake oil" humiliates a person that might have been duped,

There were too many opening contributions from Newbies" asking for them "to be treated gently", this indicates the fear people have to ask questions in the first place and they have drawn that conclusion from listening to the manner in  which questions are answered.

I have felt humiliated by responses in the past and I have thicker skin than most. I hope this warning from NSS is heeded on this new forum. Please no more personalisation against professions or products. It is not what is said it is the way it is said.

Jeremy please do not assume that people are making personal attacks against you. You have turned the comments from NSS as personal against you and last night you made it sound like I was making personal comment against you and nothing could be further from the truth, but you expressed it in a tone of conflict; simply not needed.

I thoroughly enjoy learning from this forum and share most of the points of view expressed but detest unnecessary conflict and criticism. I experience too much of that in my personal life and use the forum to escape from conflict.

I apologise for the way I came across.  All I can say is that I received a fair bit of what can only be described as "hate mail" when Ebuild closed, because someone was spreading a false rumour that I was somehow responsible for it's closure (I was not, in any way shape or form, but some don't let the truth get in the way of an excuse to let rip).  As a consequence I know that I'm taking things here more personally than I should, at the moment.   I'm trying not to, but frankly it's not easy when you've been vilified by people you've never met, for something that's not your fault. 

The tone is a problem, you're right, and I think it arises from telling the same tale over and over again.  In this case the original material, and many of the other versions, was roundly condemned as not performing as advertised many years ago, and some of us were involved in very long discussions about it, on the GBF and on Ebuild.  The manufacturers gained a pretty poor reputation for misrepresentation, had approvals withdrawn because they were based on false data, in effect, and had to change adverts.  It was such a scandal that a letter went out to all building inspectors warning them of some of the shortcomings and that some claims that the material could be used in thin layers and be compliant with Part L1A were not true.

It comes down to trust and reputation, and when manufacturers have repeatedly marketed a product with misleading claims then personally I would mistrust any claim they make about any product.  This particular thick insulation fleece product, that happens to have foil layers, is a mid-range performance insulation, if the data given is accurate, and it does seem as if this manufacturer has taken heed of the condemnation they've had from some authorities in the past and made an effort to produce a better performing, and very much thicker, product.  By the manufacturers own certification data it's performance is significantly worse than high performance sheet insulation, like PIR or PUR foam, but it is a bit better as an insulator than mineral wool, and that may well make it a reasonable choice for some applications.  It's very low decrement delay means it really needs to be used with a high heat capacity layer, but then that's also true of PIR or PUR foam.  My concern is whether or not the manufacturers data can now be trusted, given their track record.  Maybe it can, maybe it can't; people need to look at the long history and make up their own mind.

I think those of us who've been around a fair time and done a bit of research into how different materials perform do need to make a greater effort to not allow our frustration at the same topic coming up yet again show, as although it's a repeat event for us, it is often the first time the person raising the issue has come across it.  This message has been noted, not just by me, and I'll certainly try to tone things down when one of these relatively frequently raised topics comes up in future.

[DeeJunFan]

I used to be a baker of sorts.  Mostly Muffins and Pies but they were very nice.

On the debate topic i for one would rather be given an honest appraisal of a product that i was considering.  If i was to then go ahead an use that product at least i would have been made aware of any potential issues and know what questions to ask to satisfy myself that it was the right choice for me at the time.

Perhaps people take offense to the use of the term snake oil.  Here is an extract from wikipedia.

" Snake oil is an expression that originally referred to fraudulent health products or unproven medicine but has come to refer to any product with questionable or unverifiable quality or benefit "

I think the last 5 words would apply to a product that makes a certain claim that is then proven to be false, retracted and then need substantial changes to the product to make it something different but marketed as the same thing.

Also i dont think you a fool because of your choice, its only natural to have a group of people sharing information and ultimately making different choices, thats life and it would be extremely boring otherwise.  

There are products that i'm planning on putting into my house that i know full well are going to make it perform worse but thats my choice and i will live with it.  There are also products that family members have used that i have tried to steer them away from but on ahead they went and we are still happily brothers.

I for one enjoy your posts, your blog and i think your project looks great. 

For me anyway i find it difficult to get worked up about forum posts My inner voice sounds like this guy

 

[janedevon]

To update and see if my options can be improved, the timber frame company have informed me that the rafters will be 197mm deep, is there a cheaper product that I can use in a thicker format that's relatively easy to self install, bearing in mind I'm after hitting my target .16 not going excessive.

hoping to use a breather membrane, fill rafters with the cheapest easiest to fill insulation then opt for the layer beneath rafters before adding standard plasterboard.

[Jeremy Harris]

200mm mineral wool between the rafters is cheap, but won't get you to 0.16 W/m².K  without some additional insulation inside or outside to both mitigate cold bridging through the rafters and to give the needed level of insulation.  It's a reasonably good choice for a roof, though, as it has a medium length decrement delay (better than foams and other very low heat capacity insulation) and it is easier to fit than cutting foam to fit and then going around filling all the gaps with expanding foam.

I don't have my U value calculator here on this machine, but would guess that you'd get between 0.18 and 0.19 W/m².K with just the mineral wool, so you'd need to add a layer of higher performance rigid foam insulation either over the rafters or under them.  If the latter, then you can possibly use a foil-coated board and tape the joints to also give you the necessary VCL internally.

[Declan52]

One of the high density earth wool type products. Very easy to fit as it springs out and fills the rafter. Not as bad to work with itch wise as it was years ago. cuts with a hand saw. Mine was from knauf but there are others available. If you cross batten the roof on the outside and use a breather tile membrane you don't need to leave an air gap so you get the full depth. 200mm of this type of product will get you a u value near 0.16 so you could get away with 50mm pir under the rafters. Then your vcl and a service cavity if you want then your plasterboard. And as has been mentioned before the insulation underneath and the plasterboard buy it separately will be much cheaper.

[janedevon]

Many thanks, I think we are getting somewhere now so membrane, 200mm mineral wool then is the rigid foam something like celotex? What sort of thickness are we talking and will this provide a vcl if fitted correctly?  Then add standard plaster board afterwards.?  

 

[ADLIan]

+1 JSH & Declan52

200mm dense mineral wool (0.035 W/mK) underdrawn with 25mm PUR should give approx U=0.16 W/m2K (rafters at 600mm c/c). Use 30mm PUR if rafters at 400mm c/c.

Ian

[Declan52]

2 hours ago, janedevon said:

Many thanks, i think we are getting somewhere now so membrane, 200mm mineral wool then is the rigid foam something like celotex? What sort of thickness are we talking and will this provide a vcl if fitted correctly?  Then add standard plaster board afterwards.?  

 

Yep pretty much that. It has to be the higher density roll not just your standard loft type stuff. It's specific for this application. 

The thickness of the pir( Kingspan,celotex all the same) will depend on your budget. The thicker you go the better it will be but will cost more. If you tape all the joints it can act as a vcl. I taped mine and put a separate vcl in as well. Jeremy used to have a spreadsheet on Ebuild where you could play about with figures and see the difference in 50,60,70,80,100mm of pir and then weigh up with what your budget allows. Not sure it has made it over here yet.

After the pir then if you are going for a service cavity then it's done if not then plasterboard screwed through to the truss.