Tue, 19 Dec 2023 03:42:48 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18034 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18034 Wed, 22 Nov 2023 16:16:02 +0000 lineweight
The worry of course is always about moisture and the big question is how important it is for the insulation to be vapour permeable to some extent.

I've spent today trying to have a close look at what current advice/best practice seems to be. There's a bit more advice out there than there was, but there's still no conclusive answer on the importance of the buildup being moisture open. Certainly, the moisture open option seems to be considered the lower risk one.

Anyway, my main question: can anyone give me a broad idea, of what the cost implications are, now? Compared to, say, going with 60mm PIR backed insulated plasterboard on dabs (which I'd consider the "bog standard" option) - does going for something like wood fibre mean adding a lot to the cost?

I'm looking at cost of installation as well as materials here. Installation by a commercial contractor, rather than a DIY project.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18047 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18047 Tue, 12 Dec 2023 21:39:53 +0000 Peter_in_Hungary
The problem is noise transmission between the flats.

The stud wall in the attic was put in as a precursor to giving one of the flats a loft conversion. Putting in the stud wall made no difference to the sound transmission so the assumption is that the sound transmission is through the dividing wall on the ground floor rather than up through the ceiling across the attic and down to the next flat. The floors of both flats are concrete on earth and the external walls are 500mm stone / rubble walls.

What would be the best way to sound insulate the dividing wall without losing too much space and without needing a second mortgage. Preferably with any work being done from one side only.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18039 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18039 Thu, 30 Nov 2023 20:45:51 +0000 Renovationnoob
As per the name, I am a beginner when it comes to renovations. We have bought a 200sq metre victorian house with brick (uninsulated) walls, uninsulated floors, and some loft insulation. Currently there are two (relatively new) gas boilers. All the windows are relatively new uPvc double glazing.

We have around 40k (excluding VAT) to spend on improvements from an energy efficiency point of view. We are willing to do what we can ourselves (i.e. fit insulation between the joists etc.

We are considering the following steps:

1. external wall insulation - the current finish is a pebbledash (painted white) - does anyone have any view on insulated render? I have seen (some) good things about Diathonite, Cork etc. but has anyone had any success with these approaches? If we go for traditional EWI it seems as though it will eat up 20k of the budget.

2. Insulation between joists

3. Top-up of loft insulation

4. Solar PV with batteries

5. Potentially replacing one boiler with an air source heat pump?

Any tips (on any of the above) welcome.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18031 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18031 Tue, 21 Nov 2023 14:54:06 +0000 SarahLW
Hoping you wonderfully knowledgeable people can make sure I can repair holes in my eps, with silicon render.

I recently changed my internet provider and to cut a long story short I have just realised that I now have two holes in my external wall insulation through to the brick where a m8 screw has been stuck in (wiggled around a lot) and removed.

Should I just use expanding foam and cut off any that expands out the hole?


Also any recommendations for new fixings in future, on research I can see two options.

Heavy duty, drill a hole through insulation and into the brick behind insert some sort of tube to protect the insulation and then a normal fixing into the brick behind. I found the following products

tube only by swifix at the ewi store
https://ewistore.co.uk/shop/external-wall-insulation/swifix-single-tube-fitting-pack-of-10/?attribute_colour=White&mh_matchtype=&mh_keyword=&mh_adgroupid=&mh_network=x&gad_source=1&gclid=CjwKCAiAx_GqBhBQEiwAlDNAZpLww1VdfaqRNOE1fxY1w6Ga0Hh4aUwqlZcLFtxPBmXToj6uQfOXihoCoTYQAvD_BwE
Or
complete solution by Fischer Thermax
https://www.fischer.co.uk/en-gb/products/fixation-on-etics-insulation/fixing-in-substrate/thermax-8-and-10/stand-off-installation-thermax-8/45682-thermax-8-120-m6-2

They both also do a screw-in plastic grip for things like cable ties that only goes into the eps.

Has anyone used either system and got any feedback?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18030 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18030 Tue, 21 Nov 2023 14:33:24 +0000 darthgarth
We live in a 60s semi in north oxfordshire and are soon to be removing the (dreaded) finlock gutters on the property due to ingress of water the junction with the adjoining house (which had the gutters removed 7 years ago or so). A couple of things have come up in my research.

Firstly, I have only just realised that there is possibly a vent from concrete gutter block into the cavity (this would be in the section within the roof area i.e. not the water-carrying-gutter section). Would it be sensible to get the contractor to squirt in a bit of expanding foam into any cavity vents that are revealed? The cavity was filled in 2012 with what I think is knauf supafil (I have seen the certificate somewhere but not recently!).

Secondly, what would be the best strategy to insulate the eaves area? I am not sure of the final clearance to the eaves support trays that will be installed in the works, so my idea would be to buy some 20mm sheets of PIR and sequentially slide these into the eaves area to form a sandwiched wedge of insulation that closely conforms to the eaves trays but maintains airflow into the roof (with little wastage of material since no diagonal slices need to be made into thicker sheets). In effect I would end up with a boundary wedge of PIR that spans 50cm to 1m(?) of the eaves zone before loft roll takes over where the headroom to the rafters opens up. This approach would be similar to the Roof Insulation to Eaves detail as described in the Retroft Pattern Book (https://retrofit.support/detail/50/).

Thirdly, since we are not in a position to EWI the property (which I would love to do but have a forced hand due to the leaking issue), is there any value in asking the contractor to fix a thin sheet of insulation beneath the soffits? I imagine the cut edge to be pretty rough would question the insulative properties of ill-fitting 25mm PIR (for example) on such a surface.

Any advice is gratefully received...I am long time "listener" (like 13 years!), first time caller and just a home owner with an interest in retrofit and no serious DIY skills.

Cheers,
DarthGarth]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18026 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18026 Fri, 17 Nov 2023 22:22:56 +0000 blubb
Related question: I was thinking of installing another 70mm PIR board on top of the rafters. Is that a good idea in terms of ventilation/condensation/dew point?

Many thanks!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18020 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18020 Tue, 14 Nov 2023 12:51:18 +0000 sgt_woulds
Given that our parent company is located in Germany, a lot of the information we provide is translated from the original German documents and then edited to suit the UK.

One thing that has slipped through on our internal wall insulation manual is the mention of insulated back boxes for electrical installation. Unfortunately, as far as I can find, there is no equivalent product available in the UK and we should have removed this.

Que an E-mail in ALL_CAPS from an angry architect who is 'DISGUSTED that we sell natural insulation without 'THINKING ABOUT THESE THINGS'.

Explaining gently that we are a woodfibre insulation manufacturer, not an electrical factor seems to be falling on deaf ears...!

My question is, how is this normally dealt with for IWI in the UK?

Does anyone know of a product similar to this:

https://www.kaiser-elektro.de/en_DE/products/electrical-installation/flush-mounting/installation-systems-for-insulated-interior-walls/106/interior-insulation-box-for-insulation-thicknesses-30-100-mm]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18022 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18022 Wed, 15 Nov 2023 19:28:33 +0000 finnian
I'm hoping if I get underfloor heating in the new extension (about 15m2) I might be able to avoid having a buffer tank in the house, but I'm wondering what else I should be thinking of. i.e. if I should, for example, specify a large-diameter flow and return pipe to the back of the house where an external heat pump unit might go. Or maybe just put in a big conduit allowing access to the stairwell where most of the existing plumbing goes. I'm planning on at least having a 30A socket fitted at the rear to make it easy to provide power to an external unit.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18000 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18000 Wed, 18 Oct 2023 21:39:20 +0100 Warm Jake
My building is:

Top floor, 1890s enormous tenement flat in the Southside of Glasgow
Blonde limestone solid walls (around 600-800mm deep)
Lath and plaster inner walls
Drafty but pretty original floorboards throughout
U=1.0 mechanically sealed wooden sliding sash windows throughout (fitted by me a few years ago)
Well insulated roof space - in comparison to no insulation anyway
Fairly enormous rooms and huge headroom - around 3.2m
Ornate cornicing in most rooms which is in pretty good condition.
Standard gas and radiators heating.

I have aspirations to drastically but safely (for the building) reduce our energy consumption. There's some things that I just can't find almost any information on and I hope you lot might be able to give me some guidance. Some things I am planning:

- internal wall insulation (EWI out of the question, at least on the front of the building and real complicated, becasue of neighbours, on the back). Chats on that for another day.
- drastically improving airtightness and implimenting mechanical ventilation. For another day.
- installing wet UFH throughout. Initially fed from gas but future plans for alternative heat sources.

Let's pause at this.

What I am thinking to do for UFH is to build on top of my suspended timber floor. I have a huge amount of headroom and raising the floor 60mm or so would not make much of a noticeable difference. I would have to be careful with my skirting woodwork and door frames but I believe it would be a better option than destroying the floorboards pulling them all up. I've not found much information on WUFH over the top of suspended timber floor, maybe because it's mad, maybe because most buildings don't have so much headroom to play with?

Lay up I'm imagining:

Original Timber floor
Waterproof layer - line of defence from flooding downstairs neighbours if there were ever a disaster/failure.
Woodfibre insulation 30-40mm or so with 18mm UFH pipework inlayed
~18mm layer of screedboard to act as a thermal mass as well as disperse heat
Finishing layer - depending on the room...

Has anyone got any pointers on this? Is it mad?

Things I know:

- It's going to be hard to do
- I need to be very careful about insulating regarding interstisial condensation build up etc.
- It would be easier to move to a building that uses less energy (false arguement if you ask me. This building isn't going anywhere for another 100 years at least and other people would likely use a lot more energy in it).

Thanks for any support or good informaiton :)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10610 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10610 Mon, 29 Apr 2013 22:05:22 +0100 Shevek
Any good ideas for doing this in a cost-effective way? Should we just use a normal wall starter kit and then fill gap with PU foam instead of mortar?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17954 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17954 Fri, 15 Sep 2023 19:20:01 +0100 DannySheffield
My current thought is recycled plastic battens, PIR insulation, green plasterboard, plaster, and tiles or plastic panels in the splash areas (I prefer the look of tiles, but in practice we rarely clean the grout and it gets manky). But open to other options.

My main concern is minimising damp and mould, but cost and looks are also factors.

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17887 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17887 Tue, 04 Jul 2023 19:59:57 +0100 number_thirty_three
Have read a lot of different threads on here and elsewhere and if money was no object I'd be going for a limecrete/glasscrete floor, we have to be a bit leaner on the spend here so looking now at XPS, topped with underfloor heating and a thin concrete slab.

Some questions I'm looking for guidance on are:

1) The main part of the house has a suspended floor, which I've already insulated - I need to make sure it's ventilated to the rear - at the moment there are vents under the existing slab so we'll need to lay some new very long pipes to provide ventilation through the slab, which I am conscious will be thermal bridges through the insulation layer. Any suggestions on how this should be achieved? Is it best for the pipe to be as low down as possible in the insulation layer?

2) We're going to have quite a few pipes running around the place to the WC under the stairs, the new HW cylinder to the heat pump, and obvs the usual plumbing as well - all of which I guess presents a bit of a thermal bridge to the insulation layer. Other than making sure these penetrations are well sealed is there anything else to consider?

3) Do we put the XPS under the concrete slab or slab first, then XPS, then screed? Seen advocates for both options with no obvious winner...

4) What would you do for UFH in this context?


For further context, the finished floor is going to be marmoleum (Forbo's lino).

Thanks in advance :)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18002 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18002 Fri, 20 Oct 2023 13:12:28 +0100 wookey There is currently a pantry under the upper end, which we'd like to get rid of in order to have a more sensible kitchen layout.

The question is - can we take away the wall under the upper newel post (because it's actually hanging from the beam under the landing bannister) or does this type of staircase need a post down to the ground?

I did do this in a previous house and it was fine, but I'm just wondering exactly how you tell. Are all staircases self-supporting so long as the top and bottom are attached?

Here's a pic of how the newel post is currently embedded in a doorway wall:

http://wookware.org/pics/online/greenbldg/staircasesupport.jpeg

I guess it won't fall down, but it might start to creak as the newel post becomes allowed to 'swing' slightly in use?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17989 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17989 Sun, 08 Oct 2023 10:39:21 +0100 greenfinger
(Background first - the room has a vaulted ceiling (so no loft), is not currently heated, and is only used by one person. There's no kitchen.)

I've stripped some slates off my roof over the weekend to do a repair. Most of the slates are quite damp on the underside (a few are even wet, I'd say). They are also a bit flaky - still sound, but with a thin-ish layer flaking off the surface. This is both on the underside and on the top where the slate was covered by the slate above.

First and foremost, is this normal and to be expected? If it is, then great :) I'll replace the bad ones and get on with it. If it's a sign of a problem, what's the most likely cause and - dare I ask - remedy?

If it is a potential problem, there are a few factors which might be contributing and which might also solve the problem once put right. The trouble is, with the slates back on I'm not going to know in the future whether there's been an improvement. Here's those factors:

- There is currently no ventilation. The make up from inside is: plasterboard, rockwool/glassfibre, no air gap, sarking boards, felt (1f), battens, slates. I'll be putting in ventilated soffits and vented ridge, a 50mm airgap between the sarking and top of insulation, and replacing the insulation with PIR. But will adding ventilation beneath the sarking boards and felt do anything to help ventilate above the sarking boards and felt?

- Only horizontal battens were used. No vertical counterbattens beneath. So any water that makes it passed the slates has no path down to the gutters. That being said, the felt was pretty much all dry and and the battens look fine. But I didn't know if this was significant from a ventilation point of view (or whether there even needs to be ventilation between the sarking boards and slates?).

- There has been a section of plasterboard ceiling (10 foot wide 3 foot long) missing for the last year or two, along with 10" a hole in the sarking and felt. So from inside you can see the underside of the slates through that hole (the hole is from a removed flue). Given that the hole is only 10" and the removed plasterboard 10x3, could this contribute to the much larger area outside where the slates are damp/wet underneath?

Sorry for the length of the post. Any thoughts - as ever - would be most welcomed and appreciated.

Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17991 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17991 Fri, 13 Oct 2023 14:30:05 +0100 blubb
did anyone on the forum use the Great British Insulation Scheme?
(https://www.ofgem.gov.uk/environmental-and-social-schemes/great-british-insulation-scheme)
I am particularly keen to hear if anyone succeeded in getting an external wall insulation project (at least partially) funded under this scheme?

I heard about it from a colleague today; it almost sounds too good to be true. My feeling is that it should be straightforward to get funding for "simple" insulation jobs like rolling out mineral wool in the loft or cavity wall insulation (as was the case with my colleague), but probably very challenging to get more expensive projects like retrofitting external wall insulation funded under this scheme.

Looking forward to learn more about this scheme -- many thanks for sharing your experience!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17990 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17990 Sun, 08 Oct 2023 20:41:06 +0100 Victorianeco
Just trying to see if there is anything available for my new purchase or any loopholes to get funding?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17987 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17987 Fri, 06 Oct 2023 13:44:18 +0100 greenfinger
I was under the impression hot dipped galvanised is far superior, and best for any outdoor use...

I need to do some roof repairs and bought a pack of round wire nails made by Samac, for fixing sarking boards and battens to rafters. The Samac nails are sold in several roofing stores so I presumed they were exactly what I need. But it turns out they are zinc coated. And one reviewer on Amazon says he used them outdoors and they rusted quickly.

Hoping to get started on that part of the roof tomorrow. Do I need to go and buy some different nails (if I can find some locally)? Or go ahead with what I've got?

There doesn't seem to be a price difference between the two, so if hot dipped are better, I'm confused as to why so many roofing stores only sell zinc coated round wire nails? Is there a downside to hot dipped?

Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17986 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17986 Thu, 05 Oct 2023 09:28:59 +0100 blubb
looking at the cat flap designs I shudder at their poor energy efficiency.

Has anybody found any cat flaps that work well with an insulated airtight house with an MVHR?

Or maybe someone managed to find a good workaround?

I'd love to hear your experience with cats and insulation!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17968 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17968 Fri, 22 Sep 2023 10:29:03 +0100 blubb
for EWI insulation, what are the pros and cons of
a) insulating over the externally running gas pipe after protecting it by a larger diameter steel pipe rather than
b) extending the gas pipe to run on top of the insulation?

My kneejerk reaction is that b) is a poor choice because the copper pipe will act as a cold bridge and because due to thermal expansion outside of the insulated envelope it is more likely to develop a leak.

Opinions?

Many thanks!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17981 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17981 Tue, 03 Oct 2023 19:45:20 +0100 greenfinger
Apologies as this isn't really a "green" building question... But you've been a great help in my other queries, and I'm not having much luck finding an answer on this one.

I've got a repair to do to my roof. The roof has sarking boards, with 1f felt on top, battens, then slates. I'm repairing a hole in the sarking and felt from where a flue was removed. The whole area to be repaired amounts to approx. 1.2m x 1m.

I was kindly given some felt to use for the repair. I was told it was 1f but I've collected it and it's actually torch on. In fact, I was given two different rolls. One is this stuff:

https://www.jtatkinson.co.uk/iko-glass-torch-on-app-universal-underlay-16m-61020216

The other felt is thicker and I'm guessing is used for the top layer in a torch on system? Photo below of that one....

My question is whether either of these can be used instead of 1f for the repair? I'm only looking to nail it, as you would with 1f. Or do I need to make a trip to the BM and fork out for a roll of 1f?

Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17609 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17609 Mon, 17 Oct 2022 12:18:16 +0100 Davycrocket
I have a 1 storey extension built in 2005 using dense concrete blocks with a 50mm cavity insulation board installed.


There are zero exit points that are open to the elements.

Can somebody explain why when it's windy does it feel draughty as hell ?

I've sprayed foam where the plasterboard meets the ceiling in the hope it was just a case of the plasterboard not being sealed off, yet I'm still getting noticeable amounts of air coming through electric outlets and below kitchen cupboards etc ?


Do I need to take off roof tiles and check the cavity is closed or ?

Thanks in advance

Dave]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17956 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17956 Sun, 17 Sep 2023 11:55:06 +0100 Beau
When we converted our barn 15+ years ago I built some French doors. I have had problems with air tightness and weathering of the finish. I used larch which has been rot-resistant but still moves seasonally leaving poor sealing around the edges and especially where the doors meet each other. We were pressed for money so never considered expensive/high-spec doors nor had the time to build engineered wood doors. Now I really would like to have better doors. We are on an exposed site with the doors facing east. They get cooked in the summer and soaked for months on end in our Dartmoor winters. What would you recommend? I can build to a high standard but obviously, aly cladding of woodwork is beyond me. Thanks, Beau]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17919 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17919 Sun, 06 Aug 2023 17:15:22 +0100 Osprey
I am goint to have the cavity walls filled, and the roof replaced, and am thinking the latter would be a good time to fill the flues, as I should be able to access them from scaffolding outside.

So, would this be a good idea? Using EPS beads from eBay? Has anybody done this and have a ballpark figure for the amount of beads needed (I will do my own calc. but would like a sanity check! First guess is about 550liters for one full height flue)? Other comments welcomed.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17958 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17958 Mon, 18 Sep 2023 18:52:57 +0100 greenfinger
We had the roughcast render hacked off the stone wall of our house, and the pointing replaced with lime mortar. There are no foundations. At the time, I pulled back the gravel at the footings of the wall, creating a bit of a trench. There's hard compacted soil beneath the bottom stones. But in some places, there's quite a deep void until you get to the soil (a horizontal void). In the "worse" places, I can get my hand and wrist in there to around halfway along my forearm.

Should I look to fill these horizontal voids before all the gravel gets pushed back into place? Or is it enough to just let the gravel fill them? If I do fill them, what would be best to use? I was thinking NHL lime (3.5?) but also using stones under there to help bind the mortar and to prevent having to use too much of it. But that's a total guess and I'm all ears on what I should use, if indeed anything.

Aside from doing what's right for the building, it does seem that mice are quite keen to scurry their way into the wall (and house) through these deep voids. I've got them blocked with plastic at the moment to stop that. I'd want to make sure whatever I do stops mice getting in.

Pics below, showing the deepest and shallowest sections. And just to be clear, when the gravel is put back to how it was, these voids would be below ground level.

Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17966 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17966 Thu, 21 Sep 2023 17:06:22 +0100 blubb
I am looking to retrofit EWI to a 1927 solid wall brick house. I am a little bit puzzled:

- One company is suggesting to use Kingspan K5 boards [1], which are rated for outside he claims. The downside here is that K5 only comes in thicknesses up to 70 mm.

- Another company is planning to use Kingspan K103 boards [2], which are rated "water-repellent" but classed as floor boards. The upside here is that these boards come in larger thickness.

The first company with a better overall package is refusing to install K103 and insist on K5.

I should add that the insulation will go under Weber silicone-based render.

Opinions?

Many thanks!

[1] https://ewistore.co.uk/shop/external-wall-insulation/k5-kingspan-external-wall-insulation-board-0-72m%C2%B2/?attribute_pa_size=60mm&mh_matchtype=&mh_keyword=&mh_adgroupid=&mh_network=x

[2] https://www.insulationexpress.co.uk/k103-100mm]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17965 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17965 Thu, 21 Sep 2023 12:42:50 +0100 greenfinger
I bought some 24x14 slates for a repair. They mostly already have four holes. Are they still ok to re-use? I know I have to make new holes when fitting them.

Just to add, the new holes will be lower as they're going on a roof with 20x12s. I'm just using these at the abutment, where I'll cut them down to 20" in length, but needed the 2 extra inches to reach the wall. They are a bit thicker mind, but being at the end I'm hoping they'll be ok (unless anyone thinks otherwise?).

There's also one slate with a diagonal crack/line visible on both sides. It rings ok when tapped and seems sound. Is it ok to use?

Speaking of ringing, one clearly rattles when tapped, so won't use that. The rest do ring and reverberate in the hand, but it's quite a low ring. I've got other slates from another yard that ring higher and longer. Is that normal?

A link to some photos:

https://drive.google.com/drive/folders/1dKah_oULvamtboKW9kKQ4Bcr-sDWaoMF?usp=sharing

Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17964 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17964 Wed, 20 Sep 2023 14:04:03 +0100 DannySheffield
Will the limewash stay on alright if it doesn't dry out fully, or is it worth pursuing drying it fully once, before it inevitably gets damp again through the winter?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17949 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17949 Tue, 12 Sep 2023 21:01:00 +0100 greenfinger
I've finished installed soakers to my slate roof at a wall abutment, and I've cut the chase above ready for the flashing. The chase isn't mega straight, especially the bottom line This is mostly due to bits of stone and mortar falling away. And partly lack of skill ;) On top of that, the vertical bit of wall that will be behind the flashing undulates and is anything but flat.

I've dressed the soaker upstands tight to the wall. Should I do the same with the flashing or does it not need to be dressed so tightly?

Also, I was planning to keep the bottom of the flashing about 10mm above the slates. The upstand would then be around 115mm, with 35mm tucked into the chase. Where the chase is lower than 115mm, does it matter? IE - with the lead at 115mm upstand, but the bottom line of the chase only 100mm, there will be a small void behind the lead. Is that ok as is? Or should I look to pack it somehow?

I hope this all makes sense! It's been a long day. I'll try and add some photos shortly.

Any advice much appreciated.



Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17957 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17957 Sun, 17 Sep 2023 14:28:04 +0100 DannySheffield
I know asbestos is a possibility, so I'll send a sample off to make sure. Assuming it's asbestos-free - any advice on removing the insulation please? I can't see how I'll get rid of the mouldy plywood without getting rid of the insulation.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17940 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17940 Sun, 03 Sep 2023 16:40:24 +0100 greenfinger
I'm going to be stripping slates and putting in new lead soakers with a flashing next week. It's a stone wall, so the flashing will be a straight diagonal line, parallel to the top of the roof.

At the bottom, the roof extends beyond the wall by a few inches. What's the normal way to detail that? I've had a look online but not been able to find anything....

Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17578 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17578 Sun, 25 Sep 2022 10:20:45 +0100 kaicasswell
thank you in advance.
Kai]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17923 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17923 Mon, 14 Aug 2023 21:41:12 +0100 greenfinger
I’m hoping to install a ventilated ridge soon and after reading up there’s a few things I’m unsure about. I wondered if anyone could help please?

The roof is Welsh slate and has stone/concrete ridge tiles (not sure which m but they are the old type). There is ventilation already at the soffits. In case it’s relevant, the roof has sarking boards, and the felt is the old style black stuff (1f?) laid directly onto the boards.

1. Should slates be cut flush to or proud of the top battens? Strangely, at the moment the slates are cut flush on one side, but on the other they overshoot the batten by around 75mm.

2. What is a good size gap to have between the top battens at the ridge? Currently they are 105mm apart. Does that sound ok?

3. How much do ridge tiles need to overlap the slates by? The current overlap is 97mm on one side (where the slates are cut flush) and 155mm on the other (where the slates overshoot).

4. The existing felt fully crosses over at the ridge. I’m presuming this would need to be cut to create an air gap, but am I right? If so, how much to cut and remove?

5. And finally, any recommendations for a good ventilated ridge system? I want something that is effective but also that won’t look too out of place on an old house with Welsh slate. Obviously it will need to fit/overlap the slates sufficiently, given the above dimensions. And also, because we live in a very rural area, it would need to keep vermin and insects out!

Happy to upload photos and get any more details that might help with the answers.

Thanks a million for reading. I’ve been trying to answer these questions as best I can but not having much luck, so any help would be fantastic.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17827 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17827 Mon, 01 May 2023 21:45:27 +0100 mzthomps http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17935 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17935 Tue, 29 Aug 2023 09:35:56 +0100 GreenPaddy
I need to convince a client to do as much EWI as possible, and want to show examples where the front facade is left as stone, but the sides are EWI'd. The images don't have to be EWI sides, just showing the side rendered would give the idea, and that it's not unusual.

Any assistance with locating these type of photo's would be greatly appreciated.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17926 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17926 Sun, 20 Aug 2023 19:33:53 +0100 mzthomps http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17928 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17928 Mon, 21 Aug 2023 17:19:24 +0100 GreenApprentice
Following a little research, this is our current approach:

- fit the celotex or similar wall-to-wall
- Put an airtight membrane on top of the insulation - will heavy duty polythene sheet be ok, or is there a recommended better alternative
- fold it up the old plastered wall / plaster boarded walls (we have split a large room with stud walls) then tape it before plastering over it
- float the chipboard floor panels on top of the polythene leaving a small gap for expansion

I see the stud work as a thermal bridge through the insulation and also compromising air tightness, should we insulate inside the bottom of the stud wall?

We will airtight tape any electrical wire that comes up through the floor into the wall.

Is there anything else sensible that we can do to mitigate air coming up from the floor into the stud wall between the wood frame and plasterboard? I guess we could put some kind of double sided tape on the wood frame before fixing the plasterboard.

Anyone done something similar and have any product suggestions?

Thanks in advance]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17850 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17850 Fri, 26 May 2023 23:51:04 +0100 wookey
This job (floor insulation) has now reached the top of the pile so its design time.

I am trying to quantify the pros/cons of various flooring retrofits and whether to put in UFH despite limited height and thus insulation. Sums are much harder for floors than for other building elements because simple area calcs are just wrong. Has anyone come across any tools other than PHPP to help with this?
Someone must have worked out a way to do some FEM analysis with a FreeCAD model by now?

So what I have is a rectangular 1960s detached house which is all close to enerPHit grade now apart from my original concrete slab floor. I also have perimeter insulation (100mm XPS) on 3 sides down about 700mm below ground to the top of the foundation. The 4th side has a modern (2014) PH-grade extension with 170mm XPS below 150mm slab with UFH-in 50mm screed on top. Some more details at http://wookware.org/house/retrofit/

The combination of very low heat-load due to good airtightness and 3G plus U=0.15 walls all round, and perimeter insulation is one reason why I think it might still make sense to put wet UFH in the floor despite the fact that there will only be 30-50mm insulation under the pipe which various rules of thumb say is 'not enough'.
What I need is some quantification of how this all works in practice.

It seems to me that if the flooring is designed with high conductivity so most of the heat does up not down, and low flow temps so losses are minimised, this might be reasonably efficient. But maybe, in fact, it will still be worse/no better than than radiators? How to do the sums is my question.

Current flooring is 20mm parquet on 2mm bitumen. And there is ~20mm screed which comes up fairly easily in the one place I have checked so far (but one can presume that that may be quite variable across the whole ground floor. I have 60mm above the parquet to the back door threshold and 70mm above to the front door. So means we have 80mm to play with comfortably - maybe 90-100 if the screed removal works out well.

The current plan is something like:
5mm LVT (0.4 W/mK)
18mm cellecta hideck gypsum cement board (0.45 W/mK)
ali spreaders
50mm XPS or PIR containing 16mm pipe. (0.033 W/mK)

I can't find anyone selling pre-routed PUR or PIR sheets. They are all EPS or XPS. Seems to me they would be useful for the 'limited height' retrofit case.

There are plenty of suppliers that will sell you a 20mm EPS/XPS sheet along with 16 or 12mm UFH pipe to retrofit a concrete floor, but that's obviously pretty crummy (4-8mm of actual insulation below pipe - i.e. bugger-all, and thinner pipe adds to pumping loses). We can clearly do much better than that.

There are thinner floor-coverings that can work. I used 12mm multipro (calcium silicate, 0.26W/mK)) in my workshop (over XPS) and it's fine, but it's not T&G so you have add joint-pieces to stop differential movement. T&G floors are a lot less faff.

PHPP says my current overall heating demand is 52kWh/m2.a, and with the floor done as above it reduces to 35kWh/m2a, so 33% improvement. Digging up the whole floor to put 170mm XPS underneath would get it down to 28 - a 46% improvement.

But PHPP isn't allowing for the large thermal bridge of the central chimney or other internal walls on the slab which won't get insulated (maybe it has an approximation for that)? Nor that the perimeter insulation is different on one side, so those numbers are somewhat approximate.

It does show that this is the difference between enerPHit or not. (in previous iterations I did get the heat loss down to 28kWh/m2.a without the floor-digging, but I think there were mistakes. All my refinements since have made the headline number slightly worse so I'm not as close to enerPHit as I thought I was).

Hmm, I'm sidetracking myself here! What I was hoping to get feedback on was best floor-buildup options given 80mm on top of slab, how to evaluate this UFH vs radiators only (vs both), and any other useful analysis tools for how much heat goes up and how much down, and how sensitive this is to detailed material choice/thickness.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17910 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17910 Sun, 30 Jul 2023 09:28:37 +0100 jamesingram First impressions it seems a potentially good way to solve airtightness in refurb projects, especially EWI work
Here's an example
https://www.intelligentmembranes.com/c/building-solutions/air-tightness-membrane/passive-purple-brush]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17913 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17913 Tue, 01 Aug 2023 13:47:24 +0100 jamesingram I know we've been over this one a few times.
Tell me again why I can't block up the vents to a cold uninsulated suspended wooden floor when I've dropped EWI and cavity wall insulation down below dpc.
I know I'm not suppose to due to condensation, but if I don't the ventilation will just undermine the rest of the insulation.
It's nice a dry under there. If its made airtight , would it really be a major issue? :smile:]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17899 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17899 Thu, 13 Jul 2023 19:12:20 +0100 GreenApprentice
W’ve now removed the boiler and I’m repairing the botched wall that was glued back together with expanding foam. All the loose fibre insulation in the area has left the building when they knocked the more than foot square hole through to fit the tiny flue.

I’ve bricked up the outside and now wondering how best to insulate the cavity - we are doing EWI, but with what I’ve read, feel we should fill the cavity.

The complication is that the adjacent wall looks to also have lost its insulation above this level. It has a window that will be blocked up at some point in the near future and that will also need the same consideration, so using loose stuff now will probably be pointless.

Also, we have some windows and a door to block up and our wall builder guy has said to use thermalite blocks on the inside of cavity and solid blocks for the outside skin with ‘wall log’ in between. Is this ok or can we better it and could I use this ‘wall log’ or alternative in the boiler hole repair?

Thanks in advance,
Denys]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17901 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17901 Fri, 14 Jul 2023 02:14:20 +0100 alexeix
We’re extending our 1953-ish semi and the majority of the external walls will be new.
The existing walls are 260mm thick and supposedly cavity wall, however, the cavity must be tiny.
We’ll check that when the build commences.

In terms of the finished building, 3/4 of the front of the building will be the original walls, but the rest of the external walls in this be house will be new.

We’re building new cavity walls and all the external walls (new and old), will also have internal wall insulation panels fitted (37mm).
The panels will include a damp proof membrane and will be taped, and we plan to fit an MVHR system, to take care of moisture in the air inside the house.

Our concern is what will happen to the external brickwork during the winter?
If it gets particularly water logged and then we have a spell of subzero temperatures, the brickwork may get damaged.

Is there anything we can do to prevent this or should we not be concerned?

We’re in the south of England.
Thanks in advance!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17908 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17908 Wed, 26 Jul 2023 12:24:34 +0100 Davycrocket
I've finally got round to chipping off the cement render on my 1800s terraced gable end.
When the property was renovated 15 plus years ago the internal chimney breasts were removed which at the time seemed to be a good idea.

I'm now regretting that as now while chipping off I'm following a crack in the render which is revealing some dubious looking stonework and missing stov
ne pieces.


Before I go any further would it be wise to fill in the void with a cement or similar slurry type material to bind this void and outer stonework together ?

Any other ideas would be gratefully received.

Thank you in advance]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17881 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17881 Wed, 28 Jun 2023 16:12:50 +0100 Arf measures I'm trying to decide between insulating between and above the ceiling joists (to give a total of ~300mm mineral wool insulation) and insulating between and below the rafters (giving a total of 150mm foam board insulation).
There is clearly a difference in material costs (£800 for the ceiling joist option including plastic legs to support the new boards vs ~£2,500 for rigid foam insulation boards to the rafters).
However, pretty much everything else seems favour insulating the roof (more usable space, boarding out first will make it easier installing the insulation, don't have to worry about insulating the loft hatch, and ventilation perhaps less critical?).
Are there other considerations I should be aware of? I saw a previous post about roof insulation boards shrinking over time - is that a significant risk?
Many thanks in advance]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17902 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17902 Fri, 14 Jul 2023 15:30:48 +0100 Dur
Some while since I have been here which is an indication of how slow our project is taking.

We have an Edwardian dormer bungalow semi and are soon to be starting on the ground floor by removing the suspended floors and fitting UFH from an ASHP. The floor make up will be sand blinding, DPM, 150mm Jabfloor 70, 50mm PIR then 150mm reinforced concrete slab.

We are thinking on two options for positioning the UFH pipes.
First is to put them onto the PIR using clip rail (which we have) then 70mm chairs to support the reinforcing for the concrete pour. This puts the pipes at the bottom of the 150 slab.
Option 2 is is to put the mesh on the chairs and cable tie the pipe to the mesh.
(Option 1 makes the fitting of the pipes at the correct spacings etc very eay compared with option 2)


I have seen a number of discussions on both methods but they mostly seem to be in houses which are very well insulated. Our situation
is that we are aiming to get the solid walls insulated up to BC renovation standard and very well air sealed (ultimately!). Wall insulation will extend down to the bottom of the floor insulation.
The upstairs has 75mm pir between and 75 under the rafters and well taped and sealed.
So while our insulation will be massively better than it was, it is not "well" insulated by this forum's standards.

My question - will the difference in height of the ufh pipes in the slab have much of an impact in reaction times and could that be a problem? It seems to be a balance between thermal mass which would allow us to run the ASHP at lower temps but for longer for efficiency versus the reaction time if the temperature drops. But does the pipe at the bottom v the pipe in the middle of the slab make much difference?

We do have a wood burning stove for a top up on winter evenings.

Grateful for your thoughts!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17888 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17888 Wed, 05 Jul 2023 16:05:53 +0100 Osprey
However, one roofer asked if I had thought of changing to a warm roof, where no ventilation is needed.I have no plans to put a living space in the loft.

I want to do the roof replacement right: which way should I go?
Thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17897 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17897 Wed, 12 Jul 2023 19:34:14 +0100 HookHouseResto
This is my first post but I have been lurking threads ever since we moved into our new old home back in May 2022.

I've done a lot of decorating in the rooms that just needed updating and a bit of loft work on airtightness and insulation so far but I have now started the first major renovation works in our house.

Quick bit of background
A neighbour informs us that the house is of 1902 heritage, so right on the Victorian/Edwardian period border. It's a semi-detached 5br 2bath with a facade typical of the era. Mostly the walls are 2 brick solid but we do have a cavity wall on the side of the rear projection. At some point I'll share a post with the overall long term plans to renovate, including EWI, IWI, MVHR and more.

Before all that I'd like to hear input on my most pressing issue.

I've ripped out our family bathroom of 1980s vintage, unfortunately the internal plaster and lath work was not sound and didn't survive the removal of tiles and plasterboard and the external wall interior plaster suffered a similar fate. With everything stripped back the sins of the external wall have been exposed. There are small holes, cracks and great big gaping chasms in the internal leaf. Whilst I've been removing the debris I've been contemplating the best steps to improve the thermal performance of the room.

This was my original plan for the wall and I think the safest approach

1. Expose as much of the wall as I can - i.e. Remove ceiling and take up floor (done)
2. Repair brick work, removing broken bricks and replacing them with better condition imperial bricks that the previous house owner has stored in our garden. Use lime mortar (fortunately the Traditional Lime Co is a short drive from us)
3. Plumbing first fix - the waste pipe is moving to the corner of the room but apart from that major penetration nothing else should be changing.
4. Airtightness work around penetrations old and new, is foam enough or do I need to employ tapes etc.
5. Parge coat of lime product (just plain lime and sand or a thermally efficient one, please share opinions!) to improve airtightness and provide a level surface for the next steps
6. Airtightness tape applied to joist ends
7. Attach ~80mm wood fibre boards with buttered on lime product and plastic non-bridging fasteners
8. Work on the detail around the window, considering using more synthetic products here, I think that, due to the way the reveals have been constructed, I don't need to use aerogel but I still don't want this being a major thermal bridge.
9. Final plaster finish - now I'm a bit stuck at what to do here, I'm trying to use vapour open products but I also want to tile the bottom half of the wall as this is where the bath is going.
10. Tile
11. Paint upper half of wall - how well do clay paints fare in a bathroom?

Is there any problems with that?

Since its a cavity wall, is this a safer place to use something like a phenolic board (I have a pile of Kooltherm 70mm from over-ordering to insulate my sloping ceilings)? As its a bathroom it is probably a source of moisture input into the walls a lot of the time, so perhaps being vapour open wouldn't be an advantage here?

I've seen in other posts people struggling with posting photos but I shall do my best to follow up with images of the wall and problem areas. I'll also try and share a picture of the layout as the external wall is not actually a significant portion of this room.

Cheers,
Shaun]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17868 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17868 Mon, 12 Jun 2023 21:02:53 +0100 greenfinger
I've got some repair work to do soon on a single storey roof that abuts a gable end wall. The leadwork was pretty shoddy before and needs replacing with proper lead soakers and flashing. As such, a couple or rows of slates will be coming off.

I've heard it's best to use slate and a halfs where possible, rather than thin width sections of slates. But upon enquiring it seems you don't really get slate and a halves in reclaimed Welsh slates. So that leaves me two options...

1. Forget about slate and a halves, use thinner width slates as needed, and carry on.

2. Use larger format but thicker slates. One rec yard has 30" x 20" slates which could be cut down to almost slate and a half (24" x 20"). The existing slates are 24"x 14". The trouble is that these slates are quite thick compared to the existing. I've never done and am no expert on roofing so am not sure whether the slates being thicker would cause more problems than I'm trying to solve?!

Any thoughts gratefully received!

Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17876 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17876 Fri, 23 Jun 2023 18:14:22 +0100 Osprey
Is there any reason NOT to go with the work using the grant (arranged via local council, then intermediate company, then the work being done by a company called Evolve www.evolvehes.co.uk)?

I am thinking quality of work etc]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17885 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17885 Sat, 01 Jul 2023 07:25:41 +0100 Greenlady How should we prepare the floor before getting a professional tiler in ?

Owing to the cost we are having to do all the labouring jobs ourself before getting a professional tiler in to re-tile .]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17883 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17883 Wed, 28 Jun 2023 16:39:27 +0100 ballen
Having sat in a puddle of water for a number of years, the floor was completely rotten, the walls on one side are starting to go - the whole thing has dropped on the left hand side, causing the front wall to bow.

I'd like to try and save it, if possible - my idea was to jack up the wall that's failing, cut a foot or so off from the bottom and build a dwarf wall from engineering brick to sit it back down on. I plan on replacing the floor with a floating floor i.e. glued tongue and grove chipboard over celotex.

We're not entirely sure what we'll be using the space for - perhaps purely a summer house/games room or possibly as a home office. This got me thinking about insulating the structure, such that it might be useable all year round.

Given that its looking a little tired externally, the idea of installing EPS EWI and rendering is appealing, I wondered if anyone had any thoughts on this given the structure. The manufactures suggest things should not be fixed to the walls without allowing for seasonal movement of the 'logs' - I don't know how much this would be reduced by the installation of EWI. I'm also wondering if its a terrible idea as far as fire rating goes.

It seems most manufactures insulated by battening internally (on slotted brackets), filling with mineral wool and adding a VCL before cladding with wood (although I suspect this could be plasterboard if desired) and i suspect this might be a more sensible route.

Either way I would appreciate any thoughts]]>