Tue, 19 Dec 2023 03:20:53 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18040 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18040 Fri, 01 Dec 2023 10:47:01 +0000 GBP-Keith http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=289 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=289 Tue, 15 May 2007 18:00:44 +0100 GBP-Keith http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18045 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18051 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18051 Fri, 15 Dec 2023 09:32:39 +0000 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17808 http://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!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18044 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18041 http://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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18049 http://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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18048 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18052 http://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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18034 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18034 Wed, 22 Nov 2023 16:16:02 +0000 lineweight
The worry of course is always about moisture and the big question is how important it is for the insulation to be vapour permeable to some extent.

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

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

I'm looking at cost of installation as well as materials here. Installation by a commercial contractor, rather than a DIY project.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18050 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17977 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17977 Mon, 02 Oct 2023 22:29:26 +0100 an02ew
i am designing and building a small 2 bed detatched bungalow (in total 58m2 int floor) it follows our usual building fabric design:

-insulated raft foundation conncted to EWI connected to EPS loft insulation (totally unbroken insulation element and lots of thermal mass)
-ATness below 0.6 m3/m2
-MVHR (90%)
- 3g window and doors
- 3kW slimjim direct to UFH
-direct cylinder with twin immersion or instant water heaters(budget dependant)

i had this run through the new SAP10 (pre design) and it failed, not due to the fabric efficiency but becuase of the fuel price calc, it seems the only way to get a new building through the new SAP10 is with bolt on PV or ASHP (good news again for installers) In this particular build the budget is very tight and both are costly the ASHP has to low return due to the the low kW/m2/yr and the single occupant has low daytime electrical usage and no EV resulting in a low return value.

IMO SAP10 sends the wrong message, should'nt we be rewarding liftime energy efficient construction methods not short term panels and pumps?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18043 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18047 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18047 Tue, 12 Dec 2023 21:39:53 +0000 Peter_in_Hungary
The problem is noise transmission between the flats.

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

What would be the best way to sound insulate the dividing wall without losing too much space and without needing a second mortgage. Preferably with any work being done from one side only.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18046 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18016 http://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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18037 http://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?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18039 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18039 Thu, 30 Nov 2023 20:45:51 +0000 Renovationnoob
As per the name, I am a beginner when it comes to renovations. We have bought a 200sq metre victorian house with brick (uninsulated) walls, uninsulated floors, and some loft insulation. Currently there are two (relatively new) gas boilers. All the windows are relatively new uPvc double glazing.

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

We are considering the following steps:

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

2. Insulation between joists

3. Top-up of loft insulation

4. Solar PV with batteries

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

Any tips (on any of the above) welcome.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18038 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18038 Sun, 26 Nov 2023 13:02:49 +0000 Victorianeco
Also any brands preferred? I'm looking to put a few of my team on a flat roofing course but as with most things they are 'product specific' to ensure warranties are met.

Would you also try to eliminate flat roofs where possible or do they serve a purpose?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18042 http://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?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16105 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16105 Sat, 20 Apr 2019 21:32:13 +0100 philedge http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18031 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18031 Tue, 21 Nov 2023 14:54:06 +0000 SarahLW
Hoping you wonderfully knowledgeable people can make sure I can repair holes in my eps, with silicon render.

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

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


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

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

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

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

Has anyone used either system and got any feedback?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18035 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18024 http://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!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18036 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18036 Thu, 23 Nov 2023 23:25:24 +0000 Jeff B http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18033 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18033 Wed, 22 Nov 2023 13:48:17 +0000 Rex
The land for my house has a fall of around3-4 meters, front to back over about 50 m. Rainwater from the roundabout in front tends to drain onto my land a prior to building, sort of 'flooded' the front garden.

During the build, I installed a sump on the verge and took a underground drainage to the woodland at the rear of the garden. Unfortunately, I did not take photographs. Although buried on my land, the actual outlet was on the surface in the woods so that water could drain out. But 1,2, 3, or 4 meters from my boundary? Beats me?

Nowadays, the water does drain away, and then the flooding starts again. I think the outlet in the woodland has become blocked with leaves, twigs and perhaps 'someone' has made a home there. I would like to find the outlet but uncertain where it is, and it is certainly now covered with brambles, fallen branches, etc.

My question is, what would be the best way to find the outlet without actually clearing everything and digging where I 'think' it may be?

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

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

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

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

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

Cheers,
DarthGarth]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18023 http://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!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18029 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18032 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18028 http://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?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18027 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18027 Fri, 17 Nov 2023 22:36:42 +0000 blubb - One company offers to do a thorough job at reducing thermal bridges: going up to the rafters with the EWI which means redoing the soffit, insulating the 50mm wall bit around the window perimeter with 15mm thick PIR, insulating below the DPC.
- Another company is reluctant to do any of the above (it does not fit their standard programme). Their offer is however 7k cheaper.
I would appreciate some help with understanding how much "doing a proper job" at eliminating thermal bridges would really benefit the house insulation overall...
Opinions?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18026 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18026 Fri, 17 Nov 2023 22:22:56 +0000 blubb
Related question: I was thinking of installing another 70mm PIR board on top of the rafters. Is that a good idea in terms of ventilation/condensation/dew point?

Many thanks!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18018 http://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?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18025 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17942 http://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).]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18020 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18020 Tue, 14 Nov 2023 12:51:18 +0000 sgt_woulds
Given that our parent company is located in Germany, a lot of the information we provide is translated from the original German documents and then edited to suit the UK.

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

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

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

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

Does anyone know of a product similar to this:

https://www.kaiser-elektro.de/en_DE/products/electrical-installation/flush-mounting/installation-systems-for-insulated-interior-walls/106/interior-insulation-box-for-insulation-thicknesses-30-100-mm]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18022 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18022 Wed, 15 Nov 2023 19:28:33 +0000 finnian
I'm hoping if I get underfloor heating in the new extension (about 15m2) I might be able to avoid having a buffer tank in the house, but I'm wondering what else I should be thinking of. i.e. if I should, for example, specify a large-diameter flow and return pipe to the back of the house where an external heat pump unit might go. Or maybe just put in a big conduit allowing access to the stairwell where most of the existing plumbing goes. I'm planning on at least having a 30A socket fitted at the rear to make it easy to provide power to an external unit.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18021 http://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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18019 http://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?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17993 http://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?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17800 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17800 Wed, 29 Mar 2023 11:26:35 +0100 Diarmid http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18015 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18015 Wed, 08 Nov 2023 22:24:51 +0000 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18017 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18017 Thu, 09 Nov 2023 22:02:15 +0000 tony http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18012 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18014 http://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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18008 http://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]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18000 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18000 Wed, 18 Oct 2023 21:39:20 +0100 Warm Jake
My building is:

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

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

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

Let's pause at this.

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

Lay up I'm imagining:

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

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

Things I know:

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

Thanks for any support or good informaiton :)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17997 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17997 Wed, 18 Oct 2023 18:39:48 +0100 Nick Parsons
Thanks. Nick

P.S: I got this:

"The information you’re about to submit is not secure
Because this form is being submitted using a connection that’s not secure, your information will be visible to others.' and it would not send. Trying again.]]>