Sat, 02 May 2026 10:21:49 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18054 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18054 Thu, 28 Dec 2023 21:58:03 +0000 Victorianeco
The house we have 'purchased' or in the process of is completely different being a 5 bedroom detached property of cavity wall construction overlooking the Bristol Channel.

We have a few things that will need doing (ie the whole house) and I'd like to pick all your brains before GBF is no more.

Link to some photos of the property:
https://drive.google.com/drive/folders/11RqhhMeBvsiUnyTCB9q9tw3FefxZ9YaP?usp=drive_link

Our queries are as follows in no particular order:

Heating System
https://drive.google.com/drive/folders/11RqhhMeBvsiUnyTCB9q9tw3FefxZ9YaP
Standard gas boiler present - we would like an ASHP again and UFH is a must. The existing Ground floor make up is slab (assumed insulated) with a parquet top floor covering. I don't want to dig up the whole floor and insulate then 3" of screed etc. Does anyone have experience with the 25mm pre made trays that just get self levelled?. We understand the parquet would have to go if we want UFH
- Would you even use UFH or look at air-to-air systems? We're not really fans of air to air from our experience in my wifes 2 shops we much prefer the UFH
- Would electric UFH be a better system again and make use of solar and battery storage?

Single Storey Rear Extension (probably 4m x 10m)
https://drive.google.com/drive/folders/11RqhhMeBvsiUnyTCB9q9tw3FefxZ9YaP
- Would like bifold doors or slide and hide etc - recommended suppliers?
- What build would you go for? Block on flat with EWI and a pitched roof with veluxes?
- Flat roof with a lantern?
- Cavity wall?
- What slab would you go for? Or ground screws?
- Timber frame?

Thermal Envelope
- EPC suggests cavity wall insulation present (but no idea what type or how well installed)
- Assume EWI a good shout after the extension and windows are done? Or Before?

Solar Panels - South facing front elevation with both East and West facing pitches
- What is available as a grant these days if any?
- Worth getting integrated panels and renewing the roof at same time? Roof does appear in good order overall mind

Front Porch - Removal
https://drive.google.com/file/d/1B-VpHGUqUlascnhMbsdKpxQxifg7WSUV/view?usp=sharing
- We're not really a fan of the front porch it just appears to be dead space
- How easy would it be to turn into a flat roof structure and extend to the existing balcony? Assume EPDM
- Or just remove and install one grand front door

Really excited to take this on as these houses don't come up often on the road they are on and is everything we feel we need in a house]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18068 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18068 Tue, 16 Jan 2024 08:40:58 +0000 Victorianeco
It was going to be used in my renovation project but never happened

I can post the link if I am allowed?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18062 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18062 Mon, 08 Jan 2024 13:06:17 +0000 Artiglio
https://www.bpiauctions.com/auctions/?utm_campaign=Solar%20Panels%202526&utm_source=email&utm_medium=EmailRegistrants&utm_term=EmailKatherine&utm_content=Solar%20Panels%202526#/auctions/4ba10ca1-4e48-4928-ac2e-15012b184e9a?lot_status=all]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18060 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18060 Sat, 06 Jan 2024 14:08:39 +0000 minisaurus
We have a Swedish wood-frame & panel house, from 1985, with half the ground floor under ground level and with concrete walls. 115m2 over 2 stories, a 6 year-old Bosch exhaust air heat pump 2kW, 20cm insulation in the loft, maybe 10-12cm in the wall.

I've calculated we use approx 3885 kWh/year for heating, for which we currently pay approx. 11p/kWh flat-rate, so circa £427/year for heating. Our electricity is (almost) 100% fossil free.

I've considered externally insulating the wooden walls, topping up loft insulation, even removing some of the windows, building porches round the three doors. I considered MVHR, but then I'd have to buy both MVHR and a different heat pump, so probably over £25k investment in this part of the world. But my conclusion is that none of these are economically viable, or CO2 helpfull.

Our electricity deal expires in a couple of years, and we almost certainly won't get 11p/kWh flat-rate, but even so I don't see any point in doing any upgrades.

I'm interested to know if others agree with my thinking, or maybe I've completely missed something?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17808 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17808 Sat, 08 Apr 2023 11:53:01 +0100 Rex
I have a Flexit (Helios?) L4X HVMR unit which I installed when I built my house, around 12 years ago. I change the filters regularly; it runs around 8 hours per day over three different time periods. The last period is the late evening and I press the central button on the control panel for a 30 min high speed boost to remove moist air from the bathroom.

It is connected to the UFH pipework so when the UFH is on, there is a bit of pre-heating of the incoming air.

Recently, too frequently, I seen the panel (image below) with the red warning LED (top) illuminated. According to the instructions, this is an overheating thermostat warning light when the unit starts. The solution is in the loft, (very inconvenient following a both!) press the 'Reset' button. Usually, I also unplug before resetting.

Back at the control panel, sometimes pressing the two temp buttons (left and right buttons) simultaneously is necessary, but the unit then starts and works fine.

There are only two thermostats that I am aware of; one on the supply side, after the unit to measure the air temp and one within the heat exchanger. I have cleaned both.

My problem is that I have no idea what overheating thermostat actually means, where to find it and how to cure the issue.

Grateful for some advice.

Many thanks and toodle pip

The photo show the panel in warning' mode. The left/right -/+ set the temp, which with both red lights on, is 20C as need to reset via this panel. The C light is sometime on and sometime not; don't really know what it is telling me!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18057 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18057 Mon, 01 Jan 2024 16:34:45 +0000 revor https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18050 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18050 Thu, 14 Dec 2023 16:22:36 +0000 greenfinger
I've got a wood burner installed in a builder's opening. Single wall flue into a flexible chimney liner. The thin steel closure plate is higher than the lintel in front - i.e. you can't see it when stood in front of the stove. I therefore often wonder how much heat gets "trapped" in that pocket of space behind the lintel, and subsequently escapes through the closure plate into the chimney void.

So I've been thinking about insulating above the closure plate using mineral wool and wondered what people think to the idea? I've not come across much info of people doing that. Seems sensible to me but perhaps I'm overlooking something.

I did mention it to the chimney sweep when he was last here and he was against the idea. Not sure how much I trusted his opinions though (on that and other things!). One of his concerns was the mineral wool combusting. I told him that in my limited knowledge it's not combustible but he wasn't having any of it!

Any thoughts?

Many thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18056 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18056 Mon, 01 Jan 2024 15:26:38 +0000 Rex
I received regular updates from a web site called Quora; many of the questions and answers are very interesting.

Just come across this one; don't know how true is is but ...

Having read it, I did Google George Franklin and came up with many links and various interesting files.
https://www.newspapers.com/article/el-paso-times-george-c-franklin-nasa-en/132562132/

As more & more counties get more solar farms...here's some truth about solar farms. Note: the largest solar farms in Canada are in Alberta...

From a STEPHENVILLE resident, George Franklin:

I should start by telling you what bonafides I have for writing this. I am a retired aerospace engineer. A literal rocket scientist if you will. I worked on MX (Peacekeeper) Space Shuttle, Hubble, Brilliant Pebbles, PACOSS, Space Station, MMU, B2, the Sultan of Brunei's half billion dollar private 747 with crystal showers, gold sinks and 100 dollar a yard coiffed silk carpets. I designed a satphone installation on prince Jeffry's 757. I did all of the design work for the structure of Mark 1V propulsion module currently flying on at least 3 spacecraft that I know of. Some of the more exciting projects I have worked on are not shareable.
My personal projects include a spin fishing reel with a 4.5 inch spool which is entirely my own designed, machined and assembled. It has 2 features that are patentable. A unique true flat level wind and a unique line pickup mechanism. I am also am FAA certified glider pilot and FAI certified gold glider pilot. I fly both full scale and model sailplanes. I am Microsoft certified and ComTIA A+ certified.
Solar panels are at best about 20% efficient. They convert almost 0% of the UV light that hits them. None of the visible spectrum and only some of the IR spectrum. At the same time as they are absorbing light they are absorbing heat from the sun. This absorbed heat is radiated into the adjacent atmosphere. It should be obvious what happens next.
When air is warmed it rises. Even small differences in ordinary land surfaces are capable of creating powerful forces of weather like thunderstorms and tornadoes. These weather phenomena are initiated and reinforced by land features as they are blown downwind. It is all too obvious to me what will happen with the heat generated by an entire solar farm. Solar farms will become thunderstorm and tornado incubators and magnets.
Solar panels are dark and and they emit energy to the space above them when they are not being radiated. This is known as black-body radiation. Satellites flying in space use this phenomenon to cool internal components. If they didn't do this they would fry themselves.
So solar farms not only produce more heat in summer than the original land that they were installed on, but they also produce more cooling in winter, thus exacerbating weather extremes.
So I conclude with this. There is nothing green about green energy except the dirty money flowing into corrupt pockets.
There is no such thing as green energy. The science doesn't exist. The technology doesn't exist. The engineering doesn't exist. We are being pushed to save the planet with solutions that are worse than the problems.

Waddya think?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18000 https://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 :)]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18055 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18055 Sat, 30 Dec 2023 11:53:08 +0000 Warm Jake
Now, on to the subject. Idea's to run past you lot for blocking the airflow up my chimneys safely - I know it's a big no no, but I think there must be some smart ideas that could work.

Some notes:

1. I'm in a top floor 1890s Glasgow tenement with access to the attic space. All rooms have a fire place, mostly covered with a vent. I plane to open out all the fireplaces and insulate the ones which are on external walls.
2. I've got daft plans to make the flat as low-energy as possible while respecting the building and not putting it at risk of decay. The flat has a lot of amazingly crafted victorian features which I'm trying to keep.. extensive cornicing.
3. As part of my "air-tight" plan, I want to use the chimney flues to run fresh air ducting from the MVHR. Core access holes into the flue in the attic space and send a duct down to the sealing plate in the throat of the fireplace. The fireplace is normally the furthest point from the room door, so fresh air coming from here seems like a good idea.
4. I won't have the permission or desire to remove the chimney stack down to the roof level as seems to be often suggested.

1st Idea.

Simple cap on the chimney top to stop rain getting down but still vented. Airtight seal the fireplaces off at the throat with a latched gate on the seal plate. During winter months, seal off the latched gate, then in warmer months, open the gate to allow through flow. Question is, would sealing the flue from the bottom for 4-6months a year cause a serious issue?

2nd idea.

This one is a lot more involved...

Seal off the bottom end at the throat. In the attic, open a hole into the flue as near the roof height as possible. Install a sealed shelf into the flue to create an open section of flue between chimney pot and just below roof height. You then have a open flue section, about 2m deep with a sealed bottom. The issue I see with this is that air can't easily flow down to the bottom of this section and any damp ingres may not dry out. So I'm thinking of making a special chimney cap which covers the pot from rain ingres but remains vented. The top of the cap would have a rotating venturi duct with a hose that drops down to the bottom of the chimney flue void. Wind blowing across the venturi duct would create a vacuum, sucking air up the hose creating an air circulation, drawing air in from the vented chimney cap, down into the void then back up venturi hose and out.

The lower section of the flue would be sealed from elements and essentially be part of the building envelope. I would then run the room fresh air ducting down as mentioned before. The flue could then be filled with EPS balls up to the opening in the attic, especially useful for the flues on external walls.

A lot to get through there and would be better explained with some drawings. Maybe I'll draw something up.

Would be great to hear your inputs and other ideas/methods if you know of any..

Thanks,

Jake]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18052 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18052 Fri, 15 Dec 2023 10:37:24 +0000 Artiglio
As a result of some over enthusiastic estimating by the suppliers , my failure to check their properly and a few changes when it came to actual installation. I have 3 x 50m rolls of

Profi - air classic grey NW 75 radial ductin that is surplus to requirements along with 3 x 2 lengths of 125 mm round duct along with a few bits and pieces. If its of any interest to anyone drop me a line. £100 a roll or £250 for the 3.

Location is east kent, but i can strap it to a pallet for collection.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17697 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17697 Mon, 16 Jan 2023 11:20:44 +0000 tony
Any views

https://www.dropbox.com/s/a95krzr4hkhntrf/IMG_2769.jpg?dl=0]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18017 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18017 Thu, 09 Nov 2023 22:02:15 +0000 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18053 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18053 Wed, 20 Dec 2023 18:38:21 +0000 Osprey
I took up a 1920s suspended wood floor last spring, added insulation, and laid 22mm chipboard to finish. All was squeak free until the central heating (rads) came on, when one area, over the hot pipes started to squeak.

I look up the subject online, and I get the following

a) leave expansion gap of 10mm around room edge
b) glue board t&G AND glue to joists AND use many screws (including every 150mm around the edge)
c) have water/vapor proof membrane over joists, below chipboard, minimising penetrations

These are mutually exclusive. Why have and expansion gap if everything is glued and screwed so much? But I suspect expansion may be the cause of my squeak! And you cant glue to joists if you have the vapour barrier between, which would be full of screw holes anyway!

I do wonder if a fully floating floor, no screws, but T&G only glued, might be a better solution.

Anybody got any practical advice and experience, please?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18048 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18048 Wed, 13 Dec 2023 21:37:06 +0000 huwrugby
Could I simply fill the interior end of the duct with insulation or better, seal over with cement mix?

On the exterior I would be able to access the vent but only able to seal the external block & not the inner without major excavation within the room. Am I better leaving the duct & vent externally open or somehow insulating the ducting without ending up with the ducting being open to the cavity.

I hope this forum may be able to offer some advice & suggestions.

Huw]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18031 https://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?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18035 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18035 Thu, 23 Nov 2023 07:17:25 +0000 Victorianeco
I have a few people interested and recent quotes from local MCS installers are quoting ~£13000 for supply and fit... leaving £5500 for the individuals to pay themselves....

I have my own VAT registered building maintenance company but just wondering if this is worth it?

What steps one would need to take? And I assume one would need to go on a supplier course or similar?

I could install heat pumps to my wife's 2 retail premises and my own commercial unit, and I have my own house to renovate once the purchase goes through]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18045 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18045 Fri, 08 Dec 2023 15:56:08 +0000 Rex
Have a 12v 5W halogen in the garage door opening motor that has given up the ghost. Would like to replace with a wider beam angle bulb and LED seems to be the way to go.

But seems that it is not so easy to just plug one in (balanced transformer / flickering) or am I missing something?

Will any of China's finest 12V 5W LED bulbs be plug and go or do I need to fiddle with things?

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18041 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18041 Fri, 01 Dec 2023 11:52:56 +0000 JulesS The building is cut into a hillside with a narrow void between the rear wall and the hill, over the years this void has filled in with earth. Directly behind the building is a road (single track).

Our problem is there is a lot of water finding its way into the building. In an ideal world we'd dig out the void down to below final floor level and install a drain to move the water away before it gets to the building. However because the road is so close to the back of the building if we dig it out we'd be worried about undermining it. In the long term we want to insulate externally (wood fibreboard), so getting down to this level would be awesome.

From an inspection pit we can see that the original depth of the void is about 60cms higher than the final floor level so if we did dig down we'd be going lower than they originally did. There is some evidence of a retaining stone wall holding the bank back, but it's in very bad condition and has been pushed about by trees.

Digging out the void will be difficult as there's no real access for machinery, so probably would have to be done by hand.

Our current thoughts are: dig it out section by section to below eventual floor level installing a drain, put a porous membrane in and backfill with gabions filled with FGA to the original void level... I've no idea if this is a good idea or feasible, we've come to this by chatting it over with our architect and an SE. I've attached an indicative section of this.

I would love folks' opinions on this, and am open to any ideas on how to tackle it. We'd also be really grateful if folks could suggest a professional with specialism across old buildings, civil engineering (?) and drainage we could get advice from, as we're really struggling to get specific help with this.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18044 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18044 Wed, 06 Dec 2023 13:43:42 +0000 Rex
We own a first floor maisonette, built around 1960 ish, which we rent out.

The drainage from the kitchen (sink and washing machine) exit in a 4" ceramic trap on the ground near the g/f neighbour's kitchen door. Although I have asked the tenants to limit their use of oil/fat in cooking and please use liquid detergent in the washing machine, about every six months, the outlet in the 4" sump gets clogged with something (fatball?)

It is inconvenient for the g/f neighbour who expects me as the DIY (ie. cheapskate) flat maintenance expert, to clear it. Never once has he even offered a bottle of 'thank you' wine. Unfortunately, the drainage pipe extends about 2" into the 4" sump, making in impossible to get ones hand in to clear the blockage. Jet wash generally is what I use.

However, my question, is there any liquid that I can squirt into the sump that will 'dislodge/dissolve' the fatball?

Thanks and toodle pip]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18049 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18049 Thu, 14 Dec 2023 11:15:43 +0000 Doubting_Thomas
For context, we’ve identified a thermal bridge at the corners of a proposed office building. The envelope subcontractor is proposing to change the psi-value test criteria to -2° rather than -5° to scrape a pass, on the grounds that it doesn’t get that cold very often.

I’d like to demonstrate the amount of water vapour that is likely to be produced by the occupants, as a ball park figure, to illustrate why we’d be better off eliminating the thermal bridge or using a VCL than relying on balmy winters.

I scraped the following figures from the web:

• normal respiratory rate for an adult at rest is ~15 breaths per minute.
• 0.5 litres per breath, so 7.5 litres/minute or 450 litres exhaled/hour
• when you exhale, you release up to 17.5 milliliters of water/hour (assuming exhaled air is 37°C @100% RH)

The highest occupancy room is around 120 persons in a room that is 350m² and 3.5m high. So the volume is 1225m³ or 1,225,000 litres.

Average ventilation rate from AHUs is 12 l/s/person.

Internal temperature 20°, RH assumed at 50%, Dewpoint is 9.3°

So each hour, the 120 people are generating 2.1 litres of extra water vapour (120 * 17.5ml). But that is going into a space that receives (12*120*3600) 5.2M litres (?!) of fresh air in the same time period.

Does that mean I’m worrying about nothing? Or will there be other factors that I haven’t considered? Bear in mind this is just a ‘back-of-the-envelope’ assessment.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18043 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18043 Tue, 05 Dec 2023 20:16:36 +0000 greenfinger
Got plenty of caulking and filling coming up... I'd not heard of backer rod until recently, and having read up a bit on it it seems there's many others who are unaware of it. The big name stores don't seem to sell it either, which made me wonder how commonly it's used...

So, any fans of backer rod here for use in channels, chases, etc prior to caulking?

On a more technical note, there's a fair bit of online chat RE open vs closed cell. Apparently, open cell is more pliable/flexible and better for squeezing into gaps but not good if it gets wet. Also, they say closed sell off gases when cut or torn which can cause problems and even cause the caulk to bubble. But that's mainly from US sites/forums. Here in the UK, there's not much talk of it and the shops that do sell it seem to just sell "standard" stuff (which is closed cell). Does anyone know anything about this open/closed cell business?

Cheers]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18047 https://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.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18046 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18046 Mon, 11 Dec 2023 19:39:44 +0000 chrisinbrighton The roof angle is 115 degrees.
Do the experts here think the copper nails will be sufficient?

Thanks,
Chris]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18016 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18016 Thu, 09 Nov 2023 11:25:22 +0000 revor whereas the energy "certificate" says it is 111 w. The label on the back of the TV says 347W bit puzzling but maybe that may be to cover other stuff one may plug in and take power off the TV.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18037 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18037 Sat, 25 Nov 2023 12:56:37 +0000 Artiglio
In my never ending project , i’ve got to a bit of a conundrum, the building is an 1800’s 3 bay threshing barn, previously much messed with, slowly working toward converting it to a modernish home. All gone pretty well so far, I’ve now got to what will be the lounge, this incorporates 2 dwarf walls that project about 2m into the room perpendicular to the external walls on which parts of the timber frame sit. Whilst I’ve not gone overboard with the insulation on the external walls ( 60mm wood fibre) these dwarf walls need to be left as they are, but obviously represent huge thermal bridges from both the external wall and ground/foundations.
They soon discolour with condensation when it is cold outside, my plan is to have a inlet from the mvhr in the ceiling adjacent to each of them and an extract on the opposite side of the room ( which is 8m x 5m ), along with a radiator next to each of them, ( room has 4 rads, and designed to be sufficient for the room with flow rates of 50 degrees with external temps of 0) eventually there’ll be a wood stove to deal with the really cold days or the boiler will just get turned up via the weather comp on the boiler.
In my head I’m seeing a continual flow fresh air drawing any condensation that may form away from the walls , but ideally the input of generally drier external air and the heat from the radiators ( keeping the walls above dew point ) will mean humidity and temps are such that no problem has a chance to arise.

Whilst a long way from an ideal construction - planning restrictions , listed building consent and budget constraints , would this be seen as a sensible approach?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18039 https://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.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18042 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18042 Mon, 04 Dec 2023 11:42:42 +0000 rsk1
There are plenty airtight breather membranes available, but how do they actually work? Can't visualise how moisture can get through but not air

I've read on here that you shouldn't have fluff insulation in contact with ext walls as it can wick moisture onto timbers. Is that right? given that timber is already in contact with ext walls, isn't that already a risk?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16105 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16105 Sat, 20 Apr 2019 21:32:13 +0100 philedge https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18024 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18024 Fri, 17 Nov 2023 10:57:11 +0000 CJCurry
I'm in the process of renovating my house. It's a stone built, C16th, long, thin, detached off-gas house in the Yorkshire Dales National Park. It's been our family home for several hundred years and I've just taken it on, so it's a bit of a labour of love. It's getting sympathetically double glazed, insulated and generally made as energy-efficient as possible. I'm a tree surgeon and forester by profession, so have almost unlimited amounts of free firewood, which is a resource I'd like to use as my primary heat source. I've removed the very old oil-fired central heating system and designed a new system which I'd like to run by you for comment. Constructive criticism welcome. I've asked my usual plumber but because my needs are a bit non-standard they didn't really get what I'm trying to achieve.

Essentially, I have a massive 30kw water-jacketed woodburning stove in the big kitchen in the middle of the house. The hope is to burn this fully opened-up for an hour or two on a morning and evening, and keep it ticking over shut down during the day. There are also two smaller stoves with back boilers in the living room and dining room which will be lit in winter. This should fill the 2000l thermal store enough to keep the hot water and underfloor heating topped up constantly - see diagram. If I go away and don't light the stoves, the immersion heaters should kick in, or I'll set them up to be turned on remotely a day before I get back. Equally if the system can't cope with demand, the immersions will take up the slack.

To anticipate a few queries...
-All pipe runs will be in 28mm
-The thermal store is on the first floor and all stoves are on the ground floor, with pipework on a continuous gradient so it should be gravity-fed
-By the time I've finished all the renovations, there'll be seven bedrooms and five bathrooms, with potentially up to 15 people having hot showers when the house is full, hence the wish for a big unvented DHW cylinder rather than a conventional heat-transfer plate from the thermal store.


I'd appreciate it if the with experience of similar systems could sense-check this design for me. Thanks!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18036 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18036 Thu, 23 Nov 2023 23:25:24 +0000 Jeff B https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18030 https://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]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18023 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18023 Thu, 16 Nov 2023 16:37:04 +0000 enerk My house is late 80s build, no cavity insulation and renovation upstairs is almost completed. I've recently decided (based on cold bathroom in winter and growing kids closing doors in small bedrooms) that I would want to install MVHR in my house. I like the idea of not needing to open windows during window, I also lack of fresh air quite often but don't like the noise from outside.

MVHR unit will be installed in cold loft
Ideally inlet and outlet through the roof
Needs to be very quiet!
Option to install better filters
Due to long process of renovation it may for at least a year or two be used upstairs only (2 bathrooms, 3 bedrooms, 1 office, so 3inlets 4 outlets).
As mentioned before the house has poor insulation and we are not planning to add anything apart from dealing with some bigger leaks (windows etc).

My main issues questions are:
1) Can I use a large unit (suitable for 120m2 house) use partially or would that cause some issues?
2) Does providing exhaust through the roof make sense? Im worried about positioning ducting upwards.
3) What unit to choose?
4) Ideally I would want a unit I can control over wifi but do I actually need it?
5) Either the unit would be supplied with good filters or have an option to upgrade it depending on needs.
6) Noise - needs to be quiet!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18029 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18029 Mon, 20 Nov 2023 14:42:10 +0000 Rex
In the greater scheme of building questions, a question about clearing the kitchen sink rates rather low.

But I have just done it and not surprisingly, found it somewhat blocked with black algae and gunk. I have searched with Dr. Google on how to keep it clear but I really do not understand.

Pouring bicarb of soda and vinegar will probably do the job, but that mixture will not get into the trap nor will it get further along the outlet pipes to clear them, which is where my blockage was.

Other than dismantling and manually clearing the pipes, is there a 'best way' to do it?

Should point out that the gunk is not really fat/oil based at all as we use virtually no oil for cooking.

Thanks and toodle pip]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18032 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18032 Wed, 22 Nov 2023 06:27:36 +0000 Charenteman
Is a non return valve an essential component to the return leg from the pump station to the collector?
My previous install had a NRV in the pump station itself but have just noticed that this is not a feature to the pump station spec to my latest install.
There is little sunshine here at the moment, but is the lack of a NRV going to cause a significant future syphonnage problem when the sun comes out?
Thinking of modifying if I have made a significant omission here ??.
Thoughts anyone?

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18028 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18028 Sat, 18 Nov 2023 14:19:38 +0000 Simon Still
They offered the option of G4+M5 (pollen filter) filters rather than the usual G4/G4 which I went for.

I fitted a set today and (somewhat obviously) the denser filter means you need to increase the fan speed to compensate. given mine is already a little high I don't want to do that.

So
1) a warning for anyone thinking of using higher filtration filters in their MVHRs. You'll need to adjust the unit if you set it up with something else
2) does anyone want to buy these at a good discount?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18026 https://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!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18018 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18018 Fri, 10 Nov 2023 11:58:08 +0000 lineweight
We can raise the floor level by a bit - doors and so on will be replaced anyway - but not by too much, because then we will run into headroom problems.

It's an existing (damp) ground bearing concrete slab. Digging it out is not feasible. We are looking at an engineered timber floor finish. No underfloor heating. As far as I can make out the basic options are:

1) An insulated underlay straight onto the slab on top of the dpm, and the most insulative option seems to be those which are 5 or 6mm polystyrene. Of course this is not going to provide any kind of substantial insulation but hopefully "better than nothing".

2) A minimal layer of XPS70 or XPS100 insulation (say 25mm) but then you need a layer of board on top of that, then an underlay, then the flooring board itself. To bump up the insulation layer from 5 to 25mm you have to add an extra 40mm or so of buildup, because of the extra layer of board.

My question: are there any other effective options that I've not thought about?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18025 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18025 Fri, 17 Nov 2023 17:33:02 +0000 Charenteman
Can anyone advise on a set up problem with this controller ModvSol S ?
It should be a very basic S1 S2 temperature difference pumped operation between the panels sensor and solar pocket sensor.
The instruction Manual only illustrates various S1 S2 scenarios.
However when I turn the system on it illustrates S1 S2 and S3.
S1 shows nothing
The expected S1 reading is shown as S2 (48 degrees when I put the tubes in late this afternoon)
The expected S2 reading is shown as S3 (16 degrees at the solar coil area at the base of the cylinder)

The system is not running/pumping at all and I am very worried that the collectors are going to overheat if the sun returns tomorrow.

The pre wired box seems to be wired correctly.

Do these symptoms mean anything to anyone?!!

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17942 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17942 Tue, 05 Sep 2023 18:05:05 +0100 jon
Not a lot to the certification side (DNO, Build Regs, Elec certs and so on). I doubt we'll recover the cost (£250) as next stage is the battery. But signed up anyway as being non-MCS but paid export might make a second 'winter array' a worthwhile thing to do (too unique/niche to interest most installers).]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18020 https://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]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18022 https://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.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18021 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18021 Wed, 15 Nov 2023 12:22:33 +0000 owlman Prices vary massively £12- £150. My CUs are Hager and no prizes for guessing who's timers cost £150. Does anyone have any experience, good or bad, of cheaper modules.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18019 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18019 Mon, 13 Nov 2023 09:27:37 +0000 fostertom https://www.newscientist.com/article/2334240-floating-artificial-leaf-converts-energy-from-sunlight-into-fuel

But no one spells it out - where's the carbon coming from, presumably from atmosphere, or maybe from the pond water?!
Seems, at best it's capturing then pretty soon re-emitting carbon already in the cycle, rather than releasing 'new' carbon from fossil sequestration - as well as partially substituting 'harmless' green hydrogen for carbon, in this 'future' fuel mix.

“The crucial point is that we are not decarbonising the economy through techniques like these,” Reisner said. “Carbon is still a key component. What we are doing is to ‘defossilise’ the economy. We will no longer be burning ancient sources of carbon – coal, oil and gas – and adding greenhouse gases to the atmosphere".

What does the team think? What about the embodied energy/carbon, rare elements etc, in making/maintaining the 'machinery' and collecting/distributing the product?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17993 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17993 Tue, 17 Oct 2023 10:50:32 +0100 WillInAberdeen
1) has anyone had EWI applied onto an existing roughcast surface, or does it have to be chipped off first? How is it glued on without voids?

2) can a roughcast surface be applied onto EWI? Most of the systems seem to use a thin smooth top coat with much smaller aggregate in it, 3mm?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17800 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17800 Wed, 29 Mar 2023 11:26:35 +0100 Diarmid https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18015 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18015 Wed, 08 Nov 2023 22:24:51 +0000 djh https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18012 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18012 Fri, 03 Nov 2023 12:42:03 +0000 tony
The washers seem to have expanded a few mm in diameter and .3mm in thickness, see pics , what in water could cause silicone to blister yet not be harmful to us?

See below for link to photo]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18014 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18014 Mon, 06 Nov 2023 16:34:14 +0000 tony
Many of us have heard of ‘sick building syndrome’. I am going to talk in this short article about something I’m going to call ‘sick chimney syndrome’. This problem occurs when a chimney is subject to cold conditions at the same time as it gets wet either from saturation or from moisture rising from the house and condensing in the cold part of the chimney above the roof. The upshot of this is that we get a cold tropical rainforest scenario developing in the flue caused by moisture in the house being drawn up the flue by a process of diffusion without the necessity of any air movement. Moisture diffuses through the air and condenses in the brickwork of the chimney or on the capping, add my, on occasions, drip down the flue. Once this process is started, it’s almost impossible to stop it as the evaporation that will occur from the brickwork of the chimney, causes it to be colder than other places nearby, and then that in turn causes further condensation. I call this ‘pumping’ and it is where moisture from the house is literally pumped through structure and into the flue and it then condenses in the brickwork. Moisture moves through the air in a similar way to water in a pipe but no air movement is necessary for the process I am describing.

The result is that the chimney is perpetually wet and doesn’t ever dry out. My recommended solution to this problem is to ventilate the chimney immediately below the capping with two air bricks for each flue on opposite sides of the chimney, so there is a through-draft immediately underneath the chimney capping. Then it is also necessary to ventilate lower down the chimney either in the loft by removing a brick from each flue or immediately above the roofline, one brick per flue should be sufficient.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18008 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18008 Tue, 31 Oct 2023 08:49:15 +0000 borpin
https://www.bbc.co.uk/news/uk-wales-66987799

https://www.bbc.co.uk/news/uk-england-leeds-67267093]]>