Mon, 25 May 2026 04:10:10 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18418 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18418 Tue, 31 Mar 2026 18:59:32 +0100 Peter_in_Hungary
The question is - Is a VCL above the plasterboard (i.e. on the warm side of the insulation) required?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18411 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18411 Thu, 05 Mar 2026 16:48:47 +0000 oliviaaa99
Quite a lot of our electrics are in the loft& attached to the current boards. These will be removed for insulating, so we aim to attach the cables to the floor joist sides instead.

Should the order of layers go:
1) membrane > insulation up to joist level > layer of ducting with insulation around it above joists > loft boards

2) insulation up to joist level > membrane across joists > layer of ducting with insulation around it > loft boards

3) ducting with insulation around within and above joists where necessary > membrane above joists and ducting ( > potentially a layer of insulation above joists and ducting so the membrane is on the warm side?) > loft boards

4) something else? We’re open to any alternative ways as we’re not sure which is correct!

We are also not sure if we need an intelligent membrane, VCL or just airtight? For reference, the joist depth is appx 8cm and the roof is ventilated at the eaves. The floor was sealed with VCL over the subfloor but under a plywood base, and the house has been replastered/painted (still some new cracks though!).


Thank you!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18063 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18063 Thu, 11 Jan 2024 10:48:07 +0000 GreenApprentice
Been busy renovating our 1960s bungalow and making the floor and walls airtight as we do it. We’ve now completed nearly half the house in terms of living area and need to consider sorting the roof space so we can get some insulation up there. As we’re aware that the airtight tight membrane is to go on the warm side, we have been waiting to be in a position to install that before insulating, but this will require better weather as we’ll need to be doing some of the work from the outside by removing roof tiles (shallow roof space).

As we will be installing MVHR when we’ve finished all the building work, we’ve decided to install recycled-plastic insulation as the first layer (110mm) as we’ll need to be messing about with it to install vents.

The question is, can we put the airtight barrier over this layer of insulation, across the ceiling joists and then pile on other insulation, probably a deep layer of fibreglass or rockwool, the MVHR ducts will be within this layer - we’re going to create a ‘warm area’ around the loft hatch where the MVHR equipment will be housed.

It’s not the end of the world if we have to move the insulation out of the way to install the membrane if this is a complete no-no, but wanted to get a view if this would be ok as it will save time and it will be easier to install over the joists than around them.

Many thanks in advance for any advice]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14817 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14817 Sun, 08 Jan 2017 19:32:57 +0000 rsk1 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16745 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16745 Mon, 05 Oct 2020 23:22:40 +0100 graham_cbruk
I have a conundrum... we're installing a Geocell/limecrete floor with underfloor heating. I'm planning on laying engineered wood flooring but have found conflicting advice with regard to the best approach to installing it.

Some experts say you should lay the wood on treated battens with an air gap, whilst others say it's fine to float the wood on a breathable underlay. The downside of the batten approach is that the air will diminish the transfer of heat from the UFH, whilst the (possible) downside of the floating approach is that the floorboards will be damaged, over time, by moisture coming up through the breathable limecrete floor. However as the Geocell, is non-capillary, it's also possible that this will manage the moisture effectively below the UFH and leave the limecrete dry.

Has anyone else had to deal with this conundrum - and if so what solution did you settle on? I'm particularly interested in the experiences of people that have had engineered wood floors down over limecrete for some years and so have real world experience of the outcomes over a decent period of time!

Thanks in advance for any thoughts.

Graham]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18386 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18386 Sun, 21 Dec 2025 22:08:00 +0000 reed https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18375 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18375 Wed, 19 Nov 2025 23:10:46 +0000 mattp
The cavity above the window has some sort of membrane on the external side. On the other side of that is pebble dash render. It is supported on a timber frame and it is tied into the external skin of the cavity wall either side and on top of this frame is the bay window of the room above. It is completely open to the void under the floor of the room above, but there is a block wall built on top of the floorboards in the room above, which is tied into the inner skin of the cavity wall either side and supports the window ledge for the room above.

I am thinking of cutting out squares of plasterboard the right size and foaming them into position, then foaming round all the gaps to close the first floor cavity. There are also a couple of joists that go into the brickwork of the outer layer of bricks, so I was thinking of sealing these too, maybe with the same foam. Is this a good approach?

I am thinking of using one of these two foams:

https://www.toolstation.com/soudal-flexible-expanding-foam/p69089

https://www.toolstation.com/soudal-flexible-expanding-foam/p69089

I will attach 2 or 3 photos so you can see what I am talking about. Thanks.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18383 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18383 Tue, 09 Dec 2025 11:54:43 +0000 Dai Gwynne We knew that such a response was likely, and we actually submitted an alternative application where the roof is insulated from below. This has been granted approval, but particularly now that we have estimates of the cost of dropping ceilings to give us a bit more headroom, we are keen to question this policy through a Planning Appeal. The client was formerly a councillor- Liverpool's first Green Party councillor in fact - so he is not unused to pushing for changes in policy.

We want to argue that placing insulation outside the rafters is inherently safer from a condensation point of view, as well as allowing more headroom inside. We see this as a fight that may be worth taking on for the whole city (and wider?) rather than just one house. It could be useful to have expert opinion to support us in our Appeal. What evidence would be best to show. (We need to get the appeal statement in before Christmas best by say 18th December)]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18203 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18203 Sun, 29 Sep 2024 15:01:01 +0100 Victorianeco
Could I get them in 1900mm width and 1200mm height? If so I'd like 5 of them for the following property:
https://drive.google.com/file/d/1B-VpHGUqUlascnhMbsdKpxQxifg7WSUV/view?usp=drivesdk


The concern we have is that the width of 1900mm means that they'd take up a lot of room opening internally - do people really use them to open inwards or just useful for cleaning? I guess if we were to open them we wouldn't open them fully anyway, I don't think we've ever opened our existing windows fully...

By using one large pane as opposed to the existing 2 per window we feel would give better views and cleaner look from the curb

Thoughts please]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18377 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18377 Mon, 24 Nov 2025 13:54:13 +0000 mattp
I'm getting a small lean-to at the back of the house rebuilt next year, which will make an open plan kitchen / dining area when it's done. The existing floors are all suspended wood and the drawings I've had done add a new suspended floor in the new part (the new floor area is only about 2.5 m x 6 m).

I would quite like to get liquid underfloor heating throughout the dining / kitchen area (total area maybe 6m x 6 m).

I think underfloor heating is generally considered to be much better with a solid floor, but my budget is already a bit stretched so I'm fairly reluctant to get the whole area filled in and concreted.

There are some options for underfloor heating with suspended floor and I have seen examples of people doing it by insulating between the joists then embedding the pipes in a screed that sits flush with the top of the joists. My worry with this is - won't it crack with time? Also it is putting a lot of weight on the joists. The spans between the sleeper walls are small - roughly 4 feet, so I suppose it can take a bit of weight but I've no idea how much.

The other option I've seen is to replace the floorboards with a thick chipboard that has pre-cut grooves for the pipes.

My question is are either of these good options, or am I better off just installing radiators and spending my budget elsewhere?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18345 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18345 Wed, 10 Sep 2025 18:25:22 +0100 Peter_in_Hungary
The wall needs to be vertical, the question is how best to achieve this. There is not enough space to build a false wall in front of it. I am reluctant to batten out and plasterboard the wall as I am afraid that the battens will rot out in a few years and any damp from the wall would be v. detrimental to the plasterboard. Whilst the bottom part could be levelled with increasing thickness of render by the time you are half way up you are looking at about 60 mm of render which is about as much as I would want to put on, I can't help thinking that 100 mm of render at the top would be too much even if built up in layers.

What would be the best way of levelling out this wall?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18351 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18351 Sun, 14 Sep 2025 12:30:02 +0100 Victorianeco
Thinking of aluminium clad windows for all exposed area on the South Wales seafront (150m above sea level)

Any good? Website looks decent but can't find too much information on them, last post on here was 2015

Or any other suppliers? Rationel came in very high from initial costing exercise.

Also going to get some prices for aluminium, anything must be better than my 28 year old pvc windows]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18324 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18324 Tue, 29 Jul 2025 10:40:11 +0100 mattp
At the moment we have had some initial plans done by an architect and are about to proceed to get technical drawings done and calculations from a structural engineer. I have been thinking a lot about how to improve the air tightness of the house (I am gradually renovating the rest of the house) and I would like this new work to be as good as possible. My question is what should I reasonably be asking at this stage?

It seems likely that the extension will be rebuilt with a brick cavity wall to match the rest of the house. I have been reading here and in other places about cavity wall insulation and I am wondering what I should ask for. I have read that the common technique of installing PIR boards in the cavity as the wall is built can be less effective than in theory because it is hard to seal the gaps between the boards. Should I ask for the cavity to be left empty and then get it filled from the top with EPS beads after the wall is finished? Or something else?

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18347 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18347 Thu, 11 Sep 2025 14:20:10 +0100 pete-s
The top floor of the house, in the attic, has stud walls separating the rooms and stairwell from the rest of the (unheated) roof space. These walls are original lath and plaster over wooden studs. The roof is clay tiles with a felt underlay.

My plan is to fill the space between the studs with flexible woodfibre insulation and then fix rigid woodfibre over the whole lot to help increase the insulation and hopefully limit any cold bridging.

In this scenario do I need to include a VCL and where would it go in the build-up?

I've attached a top-down plan of the wall in case my description above isn't clear!

Thanks in advance!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18327 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18327 Fri, 01 Aug 2025 16:11:15 +0100 amin
The house currently has a traditional timber suspended floor, which I initially planned to replace with a solid floor using foam glass aggregate. However, upon exposing the structure, I’ve found timber wall plates embedded in both the internal and external solid brick walls, supporting the joists above the slate DPC.

If I go ahead with the solid floor, I’d need to remove these wall plates throughout. Has anyone done this before? Is it practical or more trouble than it’s worth?

Alternatively, I’ve been pointed toward a full-fill EPS solution to insulate beneath the suspended floor. I have 250mm below the 100mm joists. Would this be viable given the embedded wall plates? I’m particularly concerned about the long-term risk of trapping moisture or causing rot at the joist ends or wall plates themselves.

Interested in views from others who’ve dealt with this or have experience with either approach.

Thanks!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18326 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18326 Fri, 01 Aug 2025 12:47:05 +0100 j.neff I think the following is a good method but would like this challenged by others.

Overall plan:
EnerPHit of 1970s end terrace home in Dundee, masonry cavity wall (brick - 70 mm blowing wool insulation - AAC block), suspended timber floor. I live in the house so want to reduce internal disruption where practicable. I also want to avoid using large amounts of concrete so would like to avoid replacing the timber floor.

Air tightness strategy:
Apply (maybe self-adhesive) air tightness membrane to outside of walls (once failing render/harling has been removed) to avoid considerable disruption indoors where first floor floor would have to be lifted to seal unfinished AAC blocks and seal around joist ends.

This strategy requires making the crawl space unvented. The plan for this is:
- lift floor boards (yes, I know, it will be a pain but there is no way to work from below)
- fill bottom of crawl space with hardcore and/or dry render/harling rubble
- install DPM and tape to existing DPC in walls
- fill remaining space below and between timber joists with wood-fibre insulation
- install ProClima SolitexPlus membrane over joists
- re-install floor boards.

The ground in the crawl space is sealed with tar/bitumen and there is no obvious source of moisture through it.
A little moisture comes from the brick footings but these would end up behind the proposed DPM. Not being able to release moisture into the crawl space will likely increase the moisture content of the footings but I don't expect this to be much. Also, they will be slightly warmer than previously due to the EWI that I intend to extend to below ground level (still need to do some THERM modelling to see what effect this will have).

Does anyone see a problem with this plan or got any better ideas ?

EDIT: See my posts of 11 Aug 2025 below to correct a mistake above. SolitexPlus is the wrong type of membrane here, it should be IntelloPlus. I left the above text as I first wrote it so that the rest of this thread makes sense.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18291 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18291 Wed, 30 Apr 2025 18:16:08 +0100 DannySheffield
Stepping back, I realised the relative humidity in there is too high, and that seems to be the first thing to solve. It's 80% today (the ground floor is around 40%, first floor 20-30%).

It's a suspended timber floor, and the base of the crawlspace is old concrete (1930s house) - no damp proofing. Two external walls are cavity walls, one is solid brick and stone. There are two good air vents on the back, a good one on the side, a good enough one and a weak one on the front (the higher ground where the Apr brick is squashed up against the joists and at external ground level, so just a single air brick with reduced flow on the inside).

The air bricks were improved in February, and a few cubic metres of problematic damp soil two weeks ago

I'd appreciate thoughts on 1. the acceptable level of humidity in this context
2. Whether I might need to just wait a few months for the work to have it's full effect (and if it's worth trying to speed it up with a fan or dehumidifier)
3. Once it's settled to its new normal, how do I work out whether to focus on further ventilation or a VCL layer on the ground as my next step?

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18322 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18322 Sat, 26 Jul 2025 19:02:52 +0100 big_mike
I'm retrofitting a plastic telescopic underfloor vent (periscope type) through a cavity wall with suspended timber floor. The outer leaf has a standard airbrick opening, but the inner leaf (regular blockwork) has a much larger opening, roughly double the airbrick size.

The cavity contains what looks like shredded fibre or textile insulation, possibly recycled fabric. A surveyor reckons it was installed in the 1980s or 1990s, judging by the drill pattern in the external brickwork. It’s soft, compacted, and definitely not mineral wool or foam.

I'm also installing underfloor insulation beneath the joists, so I’m using the vent duct to drop air below that layer into the floor void.

What I need to do:
Fit a cavity closer of some sort to seal around the duct and reinstate the cavity detail

Avoid disturbing too much of the insulation if possible

Maintain air path for ventilation and prevent cold bridging or damp

Seal around the duct on the inner face of the blockwork

Questions:
Best method for fitting a cavity closer in this kind of retrofit situation?

Any recommended closers that can be easily notched to fit around the vent duct?

Should I trim back or compress the insulation around the opening, or just leave it in place?

What's the preferred method for sealing the vent where it passes through the inner blockwork? (e.g. expanding foam, fire-rated mastic, etc.)

Do I need to reinstate a DPC layer over or behind the closer?

it doesn’t need to look great, just needs to be functional, airtight, and compliant. Any tips, product suggestions, or photos from similar jobs would be much appreciated.

Cheers!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18302 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18302 Sat, 14 Jun 2025 14:39:23 +0100 Victorianeco
Standard 60s build, no insulation currently in cavity.

Windows will be going in (within proposed EWI layer) in the next 2 months, then it will be, CWI (graphite beads).

Thinking of EWI using EPS... Limited by space on the side walls of the house so EPS rather than fibre.

150mm sound okay?

Just then need to consider how to get a good 'stone sill' detail for the windows...]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18300 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18300 Sat, 07 Jun 2025 14:48:33 +0100 Dominic Cooney It’s a long story but after a power floated concrete slab fail (our friend assured us that he knew what he was doing)
And several weeks with diamond concrete grinding equipment
There is damage in a few places around the edges.
It’s unlikely to ever actually get wet because it’s all on top of EPS
It’s acting as more of an airtightness layer, so it would be a good idea to fix before progressing on to the internal timber frame.
Any suggestions welcome!
Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18295 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18295 Tue, 13 May 2025 15:13:25 +0100 enkidu
Thanks!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18288 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18288 Sat, 26 Apr 2025 20:19:34 +0100 DannySheffield
We had rockwool and netting fitted under an ECO scheme, but it got damp in multiple areas and was making timbers damp. Two different damp specialists said I should remove it, so I did. I have since cleaned out the wall cavities and improved ventilation in there. Both specialists recommended PIR board rather than rockwool, but it seems to me that the best way to avoid mould risk would be to keep it breathable e.g. with mineral wool and a breathable membrane? But I'm unsure as that is pretty close to what I ripped out last year!

Any advice/experience on a method that has the lowest risk for damp and mould, and is manageable to do well for a moderately skilled DIYer would be welcome.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18281 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18281 Sun, 06 Apr 2025 18:44:13 +0100 Peter_in_Hungary
For the walls the first thought is
Remove the tile hanging, battens and membrane then fix EPS to the 2x4s and treat as normal EWI (EPS, adhesive with mesh then thin film render to finish)
No breather membrane between the 2x4s and the EPS as the EPS will serve this function (correct ??)
For fixing the EPS to the 2x4s I would plan foam and mechanical fixings.

Would this work?

Would the sides need to be sheathed in OSB first?

If the above won't work what does the team recommend?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18277 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18277 Sun, 23 Mar 2025 12:11:15 +0000 tony
https://docs.google.com/document/d/1Qxf4WhZ0Vx68Lrk_QMv2LXBr_br7iEJ82Fd0OwdhDp8/edit

Recently following a poor surveyors report a damp specialist found high damp meter readings in the porch, bay window, loft room and under a chimney back gutter. I drilled holes in all four places collected the dust, weighed it, dried it in an oven at 120 C and re weighed it, results showed house was ‘bone dry’ % between 1.17 ams 1.78%. Damp company lost a job, sale went through and surveyor went in my bad books.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18271 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18271 Tue, 04 Mar 2025 23:36:49 +0000 mattp
I had the floorboards up for a new water supply pipe to be laid under the suspended floor and bought all the materials to insulate between the joists with wood fibre batts and make it airtight. There was also a bit of damp at skirting board level in the bay and when I checked inside the cavity there was very damp insulation (shredded fibreglass) that seemed to have soaked up moisture from below the DPC. I ended up removing all the insulation from the cavity in front of the window (but nowhere else) and also rebuilding most of the wall because it was all loose. While I was there I also fitted telescopic vents to connect the external air bricks to the internal holes. I think I am ready now to insulate between the joists and seal to the edges of the room, but I haven't done it yet because I want to know how I will finish the job in case this affects how I should do it in some way.

For the bay window originally I was thinking about leaving the cavity empty and putting some sort of IWI because a few tradesmen have told me how bad CWI is, but from reading, it seems it might not be advisable to use IWI to the sides of the bay where I still have insulation in the cavity because of potential condensation. The CWI might not be great, but I'm reluctant to get it removed everywhere, so now I am thinking of maybe just filling with EPS beads in front of the window (and leaving the existing insulation in place). I would then just need to get the wall re-rendered. Is this a good plan?

The second problem I'm scratching my head over is in the corner of the room where I have now placed a vertical radiator. This is a single 4.5" brick wall, but the last 40 cm or so into the corner has an uninsulated porch on the other side. There is a small amount of mould at the bottom of the wall in that area which I suspect is due to condensation. How can I insulate in this area? I could possibly put some external insulation on the other side, but it would have to be thin because there is a door in the porch that I don't want to replace, so I have only got maybe 40 mm to play with, including any render. Is insulating internally possible / advisable? I could move the radiator, but I'd rather not.

I will attach a few photos so you can see what I'm talking about. Thank you.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15826 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15826 Thu, 02 Aug 2018 15:51:38 +0100 andylebalcon Would appreciate input from all.
We are renovating an old farmhouse that predominantly has no insulation or heating.
So far we have insulated between ceiling joists in various rooms where we can take up loft boards and stuff sheepswool between.
Over our dining room however it is difficult to do this.
i attach a detail cross section of ceiling construction.
Above is a very large windy, unventilated loft, which we would like to use in spring and autumn (unheated/uninsulated) for yoga/spare bunkroom and the like.
In the dining room we wish to keep the feel/look of the room with the white soffit between dark chestnut beams.
So I'm looking for a insulating board that can be cut specifically to each gap fixed to underside of deck and then lined with heavy duty lining paper and painted.
At 40mm thick (or so) it will improve a great deal the insulation and we can retain the very nice cherry boards above intact.
I have considered at length taking these up, but after various thoughts and investigations and experience am unlikely to be persuaded otherwise!
Any and all suggestions very welcome
Cheers
Andy
bty I have considered aerogel but after gaining a quote I'm looking for something much cheaper.
-]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17986 https://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!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18237 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18237 Tue, 19 Nov 2024 19:36:20 +0000 DannySheffield
Has anyone else come across this? And could it be serving a purpose (e.g. stabilising walls?), or is it more likely just soil and rubble that's been dumped and would be better removed?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18250 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18250 Fri, 13 Dec 2024 14:54:03 +0000 Osprey
As I am now planning the building schedule in detail, is this approach still appropriate? The exterior walls will be rendered.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18251 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18251 Sun, 15 Dec 2024 16:54:49 +0000 Osprey
What is the best render make to avoid this staining?

I will be having a new extension smooth rendered, as well as part of the old (pebble-dashed) house: PD removal TBD. At some time in the future, I plan to have EWI applied to the rest of the house, and so ideally use the same render.

Thanks

Any thoughts or suggestions?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18243 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18243 Mon, 25 Nov 2024 18:28:41 +0000 stonecold
We are getting re-roofing and a breathable felt put in fairly soon. Obviously loft insulation will be on loft floor, with some rafter insulation only where there are sloped bedroom or bathroom ceilings below (room in roof).

Will we be able to block eaves ventilation then? What about soffit intake? Are ventilated roof tiles / slates a possible alternative?

We want to avoid attic condensation. What do EnerPHit standard houses do?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18236 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18236 Tue, 19 Nov 2024 19:27:45 +0000 DannySheffield https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18158 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18158 Tue, 09 Jul 2024 20:20:40 +0100 Victorianeco
Here is a picture:
https://drive.google.com/file/d/1jxpTRm2d6wZrf4xsZZ0Pg8Q_faVWeM_v/view?usp=drivesdk

I'd imagine they need denailing and planing/sanding/machining. Does anyone have some quick methods?

The timber is MADE IN CANADA AURENTIDE, I think it is a maple?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18231 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18231 Thu, 07 Nov 2024 12:54:36 +0000 Magpie
Yes - I know they are not the best environmentally, but I have chemical sensitivities and although I prefer natural products, I have to be able to carry out the work myself, and cannot take on cutting wood planks. Plus 3 rooms need to be done within a day or 2 of moving house.

I want to put a vapour barrier or foil over old vinyl tiles (possibility of asbestos) - and then insulation under the LVT

The issue seems to be that the insulation has to be dust free (like toxic foam) or sealed with a floor sealer (which I can’t use).

I wanted to put a non slip underlay, but apparently it is not reccommended under loose lay.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18229 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18229 Sat, 02 Nov 2024 14:56:26 +0000 Victorianeco
They do a 90mm frame which seems to be PH certified also

There's a local supplier of their windows in going to pop into and have a chat with.

Seems plenty of options available and service (initial phone call) seems promising unlike other window suppliers we have touched base with.

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18227 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18227 Thu, 31 Oct 2024 22:36:07 +0000 tony
And https://www.dropbox.com/scl/fi/5xcfndfeh8uznk2nnogns/IMG-WC-the-other-half.jpg?rlkey=7dhe4paifduwdf5n9jkapgyp9&st=0a31f8na&dl=0

An innovative WC cistern!

If anyone who can could post the two pics properly I would appreciate that, I can’t post pics]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18215 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18215 Sat, 12 Oct 2024 19:18:31 +0100 bobso
I have an old Victorian house… I’ve got an alcove that’s about 120mm deep, and 1.2m wide, looks to be a design feature! I’d like to fill this in , so was hoping that I could insulate just the alcove, the rest is solid brick, (double thickness). What’s the best way to do this? Just batten and insulate it in wood fibre, or something a bit more special? Does a gap at the bottom help with any condensation? Aware this is a partial wall, etc, and won’t be insulating the whole wall… (just the alcove). Is this worth the effort? Or is it just better to plaster board over the alcove and leave it?

Thanks
Bob]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18211 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18211 Mon, 07 Oct 2024 21:22:57 +0100 Victorianeco
In the new house the suspended timber floor is covered with 18mm T&G planks which I really don't want to remove and refit. How can I insulate the space below? I could take away the first and last route but not sure how I could pump beads in to ensure even distribution....]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18212 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18212 Tue, 08 Oct 2024 07:35:31 +0100 Victorianeco
I'm thinking of insulating the ground floor ceilings at this point for both sound and thermal (any point?)

Can I use regular 100mm isover ceiling insulation for this? As I have 12 rolls spare? Do I really need specific sound insulation? Or will this have enough benefit anyway? This is for my own home, not a flat or shared house etc.

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18190 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18190 Sun, 08 Sep 2024 22:22:11 +0100 stonecold
How long does Diathonite Evolution need to dry between layers?

What about for the final layer (before a colored lime based render goes over)?
And how long for drying any extra built-up needed to level walls in certain areas?

If it makes a difference it's going on stone with bits of slate and rubble, externally, 2 layers.

A small area is also being done internally where existing plaster will be removed first, with lime plaster finish over the top.

Second unrelated question - anyone do Diathonite right down to ground level rather than having an XPS plinth at the bottom? Wondering how that works out long term especially in areas with high rain fall. House has good drainage channels at the base of the walls. No viable DPC.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18174 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18174 Fri, 16 Aug 2024 08:12:39 +0100 Peter_in_Hungary https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18185 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18185 Sun, 01 Sep 2024 20:27:36 +0100 Peter_in_Hungary
The walls are 500 mm thick and are limestone/rubble construction.

Where possible EWI will be used, unfortunately due to boundary issues one side will have to be IWI. The plan would be to have a parge coat of lime plaster, then what would be the safe makeup for the IWI ?

The IWI should be the minimum thickness reasonable as internal space is at a premium. There are no U values that have to be achieved to satisfy regulations, I am just looking for a good option that will avoid condensation and consequential mould. The flat will be rented so proper control of ventilation (and therefore RH) will be difficult.

Insulated plasterboard is not a real option as it is not readily available here.

Should any battens be timber or would galvanised steel battens be a better option. Timber treated against insect attack is available but other treatments are not.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18194 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18194 Mon, 16 Sep 2024 09:26:21 +0100 RosieB https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18189 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18189 Sun, 08 Sep 2024 16:21:20 +0100 richy
I'm wondering if they will help though, I'm adding insulated plasterboard but space is an issue, it's a tiny house, but I'd like to work out final u values.

Any thoughts anyone? I can't see them mentioned on the online u value calculators.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18034 https://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.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18186 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18186 Tue, 03 Sep 2024 12:17:05 +0100 nbishara https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18184 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18184 Sun, 01 Sep 2024 19:58:17 +0100 Peter_in_Hungary
I would like to tile the shower room but I am concerned about putting an impervious layer over the walls that will result in problems a few years down the line. Does the team think that tiles over lime plaster will work or are there better alternatives?

The flat will be rented out so any solution needs to be robust and 'tenant proof'.

FWIW The water table is low and the ground free draining.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18181 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18181 Wed, 28 Aug 2024 03:20:11 +0100 wookey
Is it to do with slumping over time because it's relatively heavy?

I recall that for filling timber cassettes they wet it to make it 'stick' in place (even when dried out again - papier-mache style).

The bag also says it is not suitable for blowing, which also seems odd. This stuff is routinely blown into timber cassettes isn't it?

I do like the way it comes as a compact and quite solid block which you have to break up in a box with a paint-stirrer.

I couldn't find a supplier of glassfibre 'bits' fill at all. I could find EPS balls but I'm not a huge fan of those as they tend to escape. And there was plenty of mica, but that's quite poor insulation.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18172 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18172 Fri, 09 Aug 2024 13:11:52 +0100 Victorianeco
I have been quoted £2010 for 109m2 (£18.44m2) which I thought seems reasonable and they are going to see if we can qualify under Eco4 or similar which would be great

The product they propose is Superbead Graphite which appears to have a lambda of 0.032

The cavity is 80mm - what sort of U values would this product yield? Standard brick internal and external skin with render external and render/skim internal?

Questions:

- Is this a must before we even consider EWI?
- Is this suitable for a seafront property (installer said yes)
- Should we do this before or after we install new windows? We may adjust a few openings but imagine as it will be bonded there won't be fallout like the old loose fill material
- Price okay? I think it is decent and not something we could set up ourselves (compressor, spray, materials, labour)]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18156 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18156 Mon, 08 Jul 2024 11:41:41 +0100 Victorianeco
What would you replace with? 18mm OSB? 18MM P5 boards?

Also a good option to perhaps fit underfloor heating spreader plates?]]>