Mon, 25 May 2026 06:59:48 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18190 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18190 Sun, 08 Sep 2024 22:22:11 +0100 stonecold
How long does Diathonite Evolution need to dry between layers?

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

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

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

Second unrelated question - anyone do Diathonite right down to ground level rather than having an XPS plinth at the bottom? Wondering how that works out long term especially in areas with high rain fall. House has good drainage channels at the base of the walls. No viable DPC.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18174 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18174 Fri, 16 Aug 2024 08:12:39 +0100 Peter_in_Hungary https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18206 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18206 Wed, 02 Oct 2024 21:22:56 +0100 Victorianeco
We are currently renovating the new house and looking at heat pump and cylinder options under the BUS scheme, but we feel it may be better for us to install the new cylinder ourselves and get the grant just for the heat pump.

What is the best style of cylinder to future proof also? Maybe adding in a feed for PV?

THANKS]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18205 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18205 Tue, 01 Oct 2024 22:42:27 +0100 bobso
Trying to internally insulate our old coal shed. (now a study, which has been previously plastered (badly) and has various wires/ cables in the walls.

Trying to do this in natural (read water permeable materials) to help control moisture/ warmth in the shed.

Two options seem to be open to me:

1) Sheep’s wool - So Bricks, Breather membrane, Wool, AVCL, Plasterboard (and held up by battens as thermal bridges) But does let us hang pictures/ shelves to the studs.

2) Woodfibre - So Bricks, Lime coat, Woodfibre, Lime plaster (not too many thermal bridges, but hanging shelves etc difficult),

Which is best from a breathability / insulation perspective? While the coal shed isn’t wet; but it is single skin brick... Likely can do 100mm of either insulation, so both work out at a U of approx. 0.3.

If we go sheep’s wool, which seems easier to install / more like what our builder has experience with (And less lime plaster!), how much prep of the internal wall do we need to do? - i.e. does it have to be smooth etc for the membrane to go on? - Or would an old plaster and paint be ok?

Thanks for any insights!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18204 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18204 Tue, 01 Oct 2024 16:53:34 +0100 revor
"I have got a ????? bought back end of last year.

I have used it sporadically to use in power cuts and a shed with no
power and found it very useful.

However have just started using it for an LED panel to grow cress and
other micro greens and realise I am not getting the full spec.

The LED light is 35 W but getting 11/12 hours from it display shows
12hrs power when unit fully charged and showing 100% when unit is fully
charged.

So effectively 420 w not 768w that is claimed."

This is response I got and do not know what make of it.

"Thank you for contacting Customer Service Centre.
You say the problem is caused by a conversion rate issue. When the power station is powering less powerful appliances, the output conversion rate is lower,
The battery unit provides 35W at about 50-60%, so the usage time will be less. If the appliances used are more powerful, the conversion rate can reach 80%-90%, so the usage time will not be in doubt."

To me it makes no sense it is akin to saying that you can get more mileage out of an EV battery if you drive it hard but actually having a light foot give you more.
Anybody understand the response I got.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18195 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18195 Wed, 18 Sep 2024 18:54:06 +0100 blubb
I am insulating the loft space to convert it into a warm attic. I am thinking what to do with the chimney breast in the loft. It has three flues, of which one is working (wood burner in occasional use, with a steel liner, vermiculate around it). The chimney breast is channeling the cold from the roof bit and from the neighbour's loft, which is cold. Hence it seems natural to insulate the chimney breast. However, the question is:

how to insulate the chimney breast in the loft?

I believe that one could use normal insulation board like e.g. Celotex GX4100, since the flue is insulated inside the chimney breast, but since we are talking about a wood burner, I would like to hear some opinions if this would be a safe thing to do?

Many thanks!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18202 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18202 Fri, 27 Sep 2024 19:27:49 +0100 Victorianeco
So that you have the whole picture 8mm carries 1500W, 15mm-6000W, 22mm-13000W, 28mm-22000W and 35mm-34000W. For an efficient fast acting system microbore feeds should normally be restricted to runs of no more than one metre and the system pipework reduced as the load reduces.

Would you use 10mm pipe for radiators in a new install for the tails only? Looking to embed them in walls behind skirtings]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18201 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18201 Fri, 27 Sep 2024 17:52:28 +0100 tony
These used to be one bedroom = 13, 2 bedrooms 17, and 21 for 3 bedrooms

They now say 19, 25 and 31 respectively and figures are in l/s

My hobby is energy use reduction and this increase represents a 50% increase in energy use regardless of heat recovery or not !!

Nothing about occupancy

The good bit is that PIV and PSV are no longer allowed (except in Scotland) - I always felt PIV in particular was immoral (too expensive for the bill payer)

Thanks AECB - I will update my lecture notes now.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18199 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18199 Tue, 24 Sep 2024 22:56:49 +0100 big_mike https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18192 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18192 Wed, 11 Sep 2024 20:03:24 +0100 Victorianeco
Primarily because we want to renew the facade anyway, the existing render is traditional roughcast.

What is the best EWI system in terms of overall cost per r-value? From what I've seen all of the K-rend jobs in my area look awful with staining, algae and so on. What is the best finish for a seafront property that will be low maintenance?

We may look to DIY the cladding and pay to have it rendered. Can it go on existing roughcast??

And if we do install ne wiwndows in teh outer insulation layer - can the EWI be added next year or is this just asking for leaks?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18183 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18183 Thu, 29 Aug 2024 15:30:08 +0100 big_mike I’m seeking recommendations on how to effectively monitor moisture levels in joists during a long-term renovation project.

Background:

I’m in the process of planning underfloor insulation for a 1970s bungalow situated on a hillside. Alongside the insulation, I intend to install underfloor heating. Due to the hillside location, I have good access to the floor from both sides: the concrete base is approximately 1 meter from the underside of the floor at the roadside end of the house and drops to around 2.5 meters at the garden end.

Long term the goal is to approach Enerphit/Passivhaus levels where it is cost effective/sensible to do so. I have no intention of getting the place certified just want to make my home retirement ready i.e. minimise bills and maximise comfort (timeline is another 20 years till I retire)

The floor is supported by 100mm joists, and according to the "Guide to Best Practice Retrofit Floor Insulation – Suspended Timber Floors," these joists are considered a cold bridge, meaning they won't meet current building regulations. Specifically, a 4-inch joist is likely to have a U-value exceeding 0.7W/m²K, which does not satisfy the regulations.

To address this, I plan to insulate underneath the joists as well. My current approach involves extending the damp proof course (DPC) using a liquid DPC, both above and below the existing DPC. I’m considering constructing a sub-floor using thermal boards and backfilling with wood fibre batts (such as SteicoFlex) with a vapor control layer (VCL) on top of the joists. Since the thermal boards are breathable, I believe a breathable membrane underneath isn’t necessary.

One challenge I’ve identified is that the ends of the joists rest in a cavity, which seems like a potential area where moisture could accumulate and cause rot, even with breathable insulation this is an obvious cold junction.

I consulted with a RIBA retrofit architect who suggested limiting insulation to the depth of the joists and persuading building control that this is the only viable option. However, I’m hesitant about this for two reasons:

It doesn’t meet building regulations, particularly concerning cold bridging.
I aim to achieve a well-insulated floor with sufficient thermal mass to optimize the benefits of underfloor heating.
Alternative options I’m considering include:

Shortening the joists, filling the cavity holes, and retrofitting blockwork hangers.
Shortening the joists, filling cavity holes, installing a wall plate, and hanging the joists from it.
In all scenarios, the insulation strategy would remain the same.

The Question:

Given that this renovation project will likely take over 10 years and the floor will be completed in stages, I want to pursue maximum insulation and the most reliable method of supporting the joists whilst minimising the risk of rotting the joists. Any advice on installing a system to monitor moisture levels in the joists over time would be very much appreciated. As an engineer, I’m comfortable with the technical aspects of installation and monitoring but need advice on suitable equipment for this purpose and would happily learn from others mistakes!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18185 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18185 Sun, 01 Sep 2024 20:27:36 +0100 Peter_in_Hungary
The walls are 500 mm thick and are limestone/rubble construction.

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

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

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

Should any battens be timber or would galvanised steel battens be a better option. Timber treated against insect attack is available but other treatments are not.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18196 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18196 Thu, 19 Sep 2024 09:51:42 +0100 Rex
I posted some months ago regarding a 4" pipe kitchen waste blockage. I figured the 'fatball' was inside the ceramic U bend in the ground.

My tenant has cleared the blockage with a jet washer but I am going to do it again as I have a right angle fitting for car arches that will blast water directly into the U bend.

However, the owner of the g/f property where the issue occurs is quite adamant that I should get a 'professional' to investigate and clean / replace it properly, 'once and for all.' That is not going to happen unless he pays for the work, which would involve digging up a few meters of his patio!

My question is, what do 'professionals' use to clean a below ground 4" U bend? My drain shake kinda refuses to negotiated the bends, as does my 10m long sewer cleaning hose for the pressure washer.

Thanks and toodle pip]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18193 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18193 Sun, 15 Sep 2024 12:46:03 +0100 minisaurus
I'm considering getting a monobloc, and decoupling the radiator system from the EAHP. So the EAHP is only for hot water & ventilation.

3 questions about monoblocs:

Do they have to stand on concrete? Suitable places at our house are all wooden deck affairs.

Must I have glycol in the radiator pipes in case of stoppages (it can go down to -20 here ...)?

Would it be feasible to just turn the whole thing off in the summer? It's a noise/vibe thing - our outdoor seating area is often completely still & quiet in summer apart from the occasional rustle of Aspen leaves]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18194 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18194 Mon, 16 Sep 2024 09:26:21 +0100 RosieB https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18189 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18189 Sun, 08 Sep 2024 16:21:20 +0100 richy
I'm wondering if they will help though, I'm adding insulated plasterboard but space is an issue, it's a tiny house, but I'd like to work out final u values.

Any thoughts anyone? I can't see them mentioned on the online u value calculators.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18034 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18034 Wed, 22 Nov 2023 16:16:02 +0000 lineweight
The worry of course is always about moisture and the big question is how important it is for the insulation to be vapour permeable to some extent.

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

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

I'm looking at cost of installation as well as materials here. Installation by a commercial contractor, rather than a DIY project.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18191 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18191 Wed, 11 Sep 2024 18:54:19 +0100 oliviaaa99
We are hoping to make the socket and switch back boxes as airtight as possible (sealing the knockout holes, screw holes etc), but they are already installed so will need to retrofit. Is it safe to use Tescon vana to do this?

My current thought is using a strip of tape across the back/sides of the inside box to cover all the holes in one go, then to seal the hole around the wires using sealant. I've only seen posts online of people using sealant to cover every single hole, but to me it seems more efficient to use tape? So I wanted to see if anyone else has done it or if it's not recommended as we absolutely want to make sure it’s 100% safe.

I'm also not sure what exactly to use for sealant around the wires as I see some people call it fire caulk and others heat resistant silicone? This is what I'm thinking at the moment but want to make sure we get the right product: https://www.everbuild.co.uk/products/sealants/specialist-sealants/everflex-heat-mate-heat-resistant-sealant/


Thank you so much!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18186 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18186 Tue, 03 Sep 2024 12:17:05 +0100 nbishara https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18187 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18187 Thu, 05 Sep 2024 18:41:03 +0100 homdogs https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15130 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15130 Wed, 14 Jun 2017 08:17:01 +0100 Silky
apparently the cladding went up like a match stick.. I wonder what type of insulation was under there, if it was Polystyrene then surely this is a major FU!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17977 https://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?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18182 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18182 Thu, 29 Aug 2024 11:46:10 +0100 finny
Just posting to see what comes up..

Have discovered from OFGEM that our proposed heat pump installation would not attact the £7.5k grant as it would be replacing a pellet boiler that received the RHI..

Any thoughts?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18184 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18184 Sun, 01 Sep 2024 19:58:17 +0100 Peter_in_Hungary
I would like to tile the shower room but I am concerned about putting an impervious layer over the walls that will result in problems a few years down the line. Does the team think that tiles over lime plaster will work or are there better alternatives?

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

FWIW The water table is low and the ground free draining.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=464 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=464 Wed, 11 Jul 2007 21:28:11 +0100 a.bijl
I am stuck on the question of a suitable green treatment for moth-proofing the fleeces. Anybody got some experience or ideas about what and how to do this?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18119 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18119 Mon, 15 Apr 2024 17:56:06 +0100 djh
Getting an EV at last this week. Been looking at Octopus Intelligent Go and the way I read it you can get your cheap electricity at night as well as exporting during the day at fixed 15p per Kwh. Last time I looked into it you could not have both when you had outgoing tariff.
.
Seems win win if I read correctly. I would instinctively charge during the day using solar that would normally go to export but looks like best to export for 15p and buy back at 7.5p at night during the 6 hour slot. Seems to be to good to be true.

Anyone on here that can comment on it.?"]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18181 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18181 Wed, 28 Aug 2024 03:20:11 +0100 wookey
Is it to do with slumping over time because it's relatively heavy?

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

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

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

I couldn't find a supplier of glassfibre 'bits' fill at all. I could find EPS balls but I'm not a huge fan of those as they tend to escape. And there was plenty of mica, but that's quite poor insulation.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18138 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18138 Mon, 03 Jun 2024 21:19:33 +0100 Mike1
- a tiled pitched roof attic that's subdivided into storage units used by various residents
- terracotta floor tiles in lime mortar
- thick timber planks
- joists at close centres that span between beams.

to which I'm adding insulation and a dense plasterboard ceiling.

Being rather tricky, I thought I'd better commission a WUFI analysis, and being optimistic I thought I'd kick off seeing what the results would look like with 300mm of hemp insulation batts. The results are now back and don't look pretty. With luck, the images will be below.

I'm now considering how far to change the spec for another run of WUFI. I know that some of you - Tom, maybe Tony, maybe others? - have played with WUFI in the past, so am hoping that you may have some thoughts on this.

An obvious track would be to cut the insulation. 200mm would be my ideal minimum (U = 0.21 W/m²K). In view of the results for 300mm, any opinions on this or an alternative thickness?

No doubt adding a smart VCL would make WUFI results look better, but in reality the stud partitions would pass through and bypass it (they're fixed to the structure). That's leaving aside the advisability of using VCLs in retrofit anyway (I think my scepticism is shared with Tom too?).

So, as I don't have endless funds to spend on WUFI models, what to try next?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18172 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18172 Fri, 09 Aug 2024 13:11:52 +0100 Victorianeco
I have been quoted £2010 for 109m2 (£18.44m2) which I thought seems reasonable and they are going to see if we can qualify under Eco4 or similar which would be great

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

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

Questions:

- Is this a must before we even consider EWI?
- Is this suitable for a seafront property (installer said yes)
- Should we do this before or after we install new windows? We may adjust a few openings but imagine as it will be bonded there won't be fallout like the old loose fill material
- Price okay? I think it is decent and not something we could set up ourselves (compressor, spray, materials, labour)]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18179 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18179 Sat, 24 Aug 2024 19:40:41 +0100 Artiglio
I may well be late to this party ,but just in case.

A Nest has been my heating thermostat for about 3 years. Over that time i’d noticed that the boiler would fire at times for no reason. Lots of checking of wiring etc, never solved it and as it was seemingly intermittent ( and over heating season went unnoticed) however last few weeks i seemed to notice it most days.
A bit of online enquiry, throws up that nest has a built in Legionella feature, it will fire the boiler and run the hot water circuit if water hasn’t been heated for an uninterrupted 2hour period in the last 48 hours.
Plus my boiler is unable to have seperate flow temps for hot water priority or heating and so i set it at 55 , unless it’s below zero when it gets increased. ( despite being opentherm compatible, i’ve never managed to get it to work with the nest) Boilers a Baxi system.
Absurd when my tank needs less than an hour to recharge and i’ve got the water programme set accordingly. Plus the Nest can’t read either the boiler flow temp or tank temp, so relies on the boiler being set high enough along with the tank to achieve its aim.
So out of heating season it would seem i’ve had the boiler running most days for 2 hours for no reason.
The Bacteria control setting can’t be accessed in the App only through the stat itself.
Seems a rather pointless feature and one which should be flagged more prominently.
Remains to be seen how much effect it has on my gas use.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18156 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18156 Mon, 08 Jul 2024 11:41:41 +0100 Victorianeco
What would you replace with? 18mm OSB? 18MM P5 boards?

Also a good option to perhaps fit underfloor heating spreader plates?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18169 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18169 Sun, 04 Aug 2024 21:39:55 +0100 Victorianeco
Would you insulate between joists also while the boards are up or not bother as the whole house will work as one anyway?

We have decided against underfloor heating and will opt for a radiator instead]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18177 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18177 Thu, 22 Aug 2024 12:23:37 +0100 Victorianeco
Is there a preference in type? Are thermally efficient lintels actually worth it?

Finally - any recommended supplier? The largest lintel would need to be ~4.5lm including bearing As it is a ground floor am I right in just saying the suppliers would just have standard specs?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18176 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18176 Tue, 20 Aug 2024 21:33:50 +0100 Victorianeco
We have a very good view of the sea from this elevation so need to weigh up views against energy efficiency but there's more to a building than U-Values after all..

My understanding is try to limit windows to no more than 25% of wall area on South facing elevations?

Is there any best practice on how high the head of windows should be? Our ceiling height is a standard 2400mm and the existing windows are 400mm below ceiling level. We will be installing a larger cavity lintel to have one larger window compared to the 2 windows in each room. We can raise the height to maximise daylight - is there a preferred standard/height?

We are also undecided if we are going to EWI or just go with cavity bead fill so that will determine where we mount the frames.

And age old question so we can get some prices together - 2G or 3G...]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18153 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18153 Mon, 01 Jul 2024 15:12:18 +0100 fostertom http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18146&page=1#Item_26 .

I also found the WUFI 5.1.exe, which loaded and opened, where previously it had been time-limited to 6wks following the WUFI course. So, back in business! tho am sure to pay to legit-upgrade to current WUFI 6, which I think has changed a lot.

In that thread, the construction discussed was:

--------------

Rafters (or studwork), plasterboard, skim and vapour-breatheable paint internally, which can be punctured at will for electrics etc; 12 ply sheathing (or 11 OSB3) gapfilling (polyurethane) glued and screwed/nailed externally, as air barrier, blown full of Warmcel insulation.

EPS (or wood fibre) insulation; if 95 rafters then 150 EPS; if 145 rafters then 100 EPS, glued external to the sheathing EWI-style, with highly gappy glue application, to allow unimpeded water vapour passage. Board-edge joints filled with expanding foam, by long nozzle pushed in full depth, so filled full depth from inside outward. Bead-board EPS is by far least environmentally offensive, compared to any foam-board insulation such as PIR, and is sufficiently vapour-breatheable.

Breather underslating felt, downslope battens, crosswise tiling battens, tiling.

This design, fully breatheable without any vapour barrier (VCL), results from my one opportunity, years ago, to play with WUFI. I tried many use-cases, and for this type of construction, found it performed much better without any VCL. Note, there is a (vapour permeable) air barrier layer and a (vapour permeable) external wind barrier layer. I put this superior performance down to its maximisation of re-drying potential, unimpeded both outward and inward. With or without VCL, there is, at some times of the year, interstitial condensation in the outermost centimetre(s) of the EPS, but this is harmless as there's no embedded timber in that zone. Neither EPS or woodfibre mind such intermittent wetness, as long as fully re-dried soon enough, whether diunal (winter sunny day) or seasonal (after a long cold winter).

--------------

I find the case studies neatly arranged and hopefully useable to convince Bldg Insps. We shall see. Screenshots attached:

WUFI 1 OSB shows the water content in the mid-sandwich OSB layer, with no VCL.
WUFI 1 EPS shows ditto in the outboard EPS layer;
WUFI 5 ditto ditto are with standard inboard VCL.
WUFI 6 ditto ditto are with Intello variable VCL.

Intello works better than standard VCL. But no VCL at all works much better than both!
What do we make of that?

Note that vertical scales differ, so need to look at the numbers, not just graph shape. Print em out - hard to compare otherwise.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18178 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18178 Thu, 22 Aug 2024 13:19:53 +0100 djh
https://www.coatingsworld.com/contents/view_breaking-news/2024-08-19/solar-energy-breakthrough-could-reduce-need-for-solar-farms/

e.g.

"This ultra-thin material, using this so-called multi-junction approach, has now been independently certified to deliver over 27% energy efficiency"

"At just over one micron thick, it is almost 150 times thinner than a silicon wafer. Unlike existing photovoltaics, generally applied to silicon panels, this can be applied to almost any surface."

I've no idea what the implications are.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18175 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18175 Sat, 17 Aug 2024 22:22:38 +0100 wookey I heard about them on the Zero Ambition podcast and they seem a very sound outfit. We've been very short of UK manufacture of natural insulation so it's good to see some happening.

I need to top up my loft and do some insulating around the eaves and some slightly-flexible woodfibre or hemp batts seems like a good material to use (move any moisture away from the joists and a bit of squishiness helps with the awkward shapes). But it does matter how easy it is to cut as I need to make diagonal 160mm cuts to make a wedge-shaped base piece.

I know sheepswool (Thermafleece) is extremely difficult to cut. Fluffy woodfibre is easy - solid woodfibre is more or less like timber. Semi-rigid rockwool batts are easy. I have no idea where hemp batts fall on this scale.
Looks like they have loft batts (IndiLoft) and flexible wall batts (IndiTherm) available now with semi-rigid boards coming any day now. The IndiTherm appears to be reasonably widely available already (e.g. from ecomerchant).

There is a youtube vid here showing cutting with a 'wavy edge' insulation saw: https://www.youtube.com/watch?v=AoiPd8VM3bQ
I'm not familiar with those. That makes it look to me like it's harder to cut than soft woodfibre but easier than thermofleece, but it's quite hard to tell.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18167 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18167 Fri, 26 Jul 2024 12:32:06 +0100 sluggy https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17079 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17079 Tue, 01 Jun 2021 08:24:52 +0100 jms452
It's also nearing the end of its life so I'm wondering if microwave standby has improved in line with other items but looking around the usual sites I can't see standby power mentioned anywhere.

To avoid me being 'that guy' with an energy eye plug arguing with the assistant in Currys:

Is there a data base for microwave standby power anywhere I'm missing?
Has anyone on GBF measured the standby of any current models?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18160 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18160 Fri, 12 Jul 2024 10:50:19 +0100 maxsm1
After a long period of planning we are (hopefully!) a few months away from building work beginning on our eco retrofit project. There will be 300mm insulation in the roof, 200mm on the walls and 50mm overlaid on top of the existing concrete floors. This is expected to achieve around 30kwh/pa heating demand and we are aiming for airtightness to be somewhere in between enerphit and aecb.

We would like to switch from our gas boiler to an ASHP but are right up against it budget wise and can't afford to dig up the floors for ufh.

I have a couple of questions I'm hoping you can help with:

Given that our house will have relatively low heating demands is combining an ASHP with radiators a viable option?

If we do go down the ASHP/rad route, how can I calculate radiator sizing for individual rooms?

And how can I calculate an appropriately sized ASHP?

Also interested in any opinions on the merits (and cost!) of steel vs aluminium radiators.

Thanks in advance for any help]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10758 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10758 Sat, 08 Jun 2013 09:57:25 +0100 PeterW
Following a couple of discussions, here is a simple Excel based heat loss calculator and domestic heating sizing method.

Based on the Energy Saving Trust paper fact sheet and calculator, you will need to download both as the instructions are in the PDF

http://www.energysavingtrust.org.uk/Publications2/Housing-professionals/Heating-systems/Domestic-heating-sizing-method-2010-edition

https://docs.google.com/file/d/0B4rLWre5MvQQWm5CMVJ2VTdUcUE/edit?usp=sharing

If you do spot any errors in it please let me know and I will update it

Thanks

Peter:bigsmile:]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17811 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17811 Sat, 15 Apr 2023 19:07:28 +0100 Victorianeco
It's a 2 bedroom bungalow with hipped roof, looking at adding a dormer and possibly double extension if possible.

Something I've always been interested in (architecture design) but never really persued it

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18147 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18147 Wed, 19 Jun 2024 10:18:49 +0100 Huwblut
The ceilings are down on my little bungalow renovation and I’m thinking hard about how to re insulate them. I think the electrician would appreciate it if we’re all gone while he’s working from underneath.


Previous posts recommended a fluffy product of some description. I’ve seen this advertised on marketplace local to me for £30 per roll : Rockwool Therma insulation roll 100/200. Any opinions please?

Question is there something similar / less expensive & possibly less itchy out there?

I’m keen to reuse the existing stuff despite it being a horrible job to remove, store and re install. Seems a shame to send it landfill.

Suggestions greatly appreciated

Huw]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17141 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17141 Thu, 05 Aug 2021 12:37:18 +0100 Shevek
We're thinking to exchange the gas boiler for a hot water cylinder with integrated air source heat pump (e.g Dimplex Edel, Energie Aquapura Monobloc etc. that can vent directly through the external wall) and fit a few electric infrared or convection panel heaters. (there is EU funding available here up to €2500 to fit new heat pumps, solar thermal, PV etc.)

But if we're going to the trouble of fitting such a unit and we really want to lower our heating bills then would we be better to fit a heat pump that can also provide central heating?

Problem is I can't find hot water cylinders with integrated heat pumps that can provide this level of output.

We're on the first floor of a 4 storey block of flats and while it might be feasible to fit something on the roof I'd rather avoid that option if we can. First we'd need to get permission, then we need to find a route, it would need to be close enough, and then we'd need to be sure we're not create a noise nuisance for the top floor (the building performs very badly acoustically).

Are there any integrated units on the market that can provide central heating?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18168 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18168 Mon, 29 Jul 2024 10:54:40 +0100 Rex
Here is a tale of woe, fortunately, not mine.

When I built towards the end of a private cul-de-sac, three other houses where lined up for the go-ahead.

As an aside, mine is a TF house with Warmcell insulation. Two of the others are standard brick/block builds, the third is a very modern design on a triangular plot with a tight footprint. They increased the floor area with a basement and built with SIPs.

It has all mod-cons; Cat 6 throughout (apparently not used as wi-fi is now the choice), MVHR, UFH, triple glazing, air source heating, solar panel on the roof, etc. Also balconies front and back, below which are the lounge and kitchen. The balconies are not particularly deep with low walls and the frameless glazing inserted into channels, embedded into the walls.

Similar to this but the channel set into the top of the wall so the ali was not visible. Whatever the actual structure was, it seems the project manager did not follow all the specified guidelines.

About one year ago, they had water dripping from a kitchen downlight. Could only be from the balcony as there are no potable water pipes in the vicinity. Could be from the UFH but the specific light has the balcony above.

X amount of research and experts with boroscopes and it was decided that rainwater was entering via the top of the dwarf wall where the glazing is, and not being drained where it should, so finding the easiest path, which was through the downlight. The temporary solution for the past year, was a sheet of plastic over the glazing and the top of the wall to prevent water entering.

The longer term solution is very expensive. Fortunately, they are just within the 10 year NHBC warranty. Extensive research for a builder and not surprisingly, no-one wants to do the job at a fixed price because, until the panels are removed, no-ones knows the extent of any damage. However, they managed to arrange an open-ended solution with the insurance company and as I write, the repair is proceeding.

Having removed the render board, it was found that many of the external SIP osb panels had totally rotted at the lowest edge.

The rear was not a problem as such, but since the construction was the same, it is also being repaired. The balcony and insulation was removed, a waterproof membrane laid, new insulation installed, wbpover the insutlation, then a resin waterproof layer onto which, the tiles are laid. Also, a very substantial steel angle beam fitted, providing a drip edge which previously did not exist, and into which, the fittings to support the new glass balustrade. Then new render board and re-rendered.

The front is similar, but different as the entire kitchen wall has three narrow windows. Those have been removed as have the badly rotten SIPS. New SIPS installed and windows replaced, the balcony will receive the same treatment as the rear, new render board and steels to support the glazing, which will no longer be attached directly to the walls.

But he woes do not end there!!! Part of the roof is zinc and part is flat with a 1m up stand. All the walls have a zinc capping, but no-one checked if there was cavity ventilation. Of course, there was not. So ventilation ducts are being added to the bottom of the walls and new capping will be fitted with ventilation gaps and a standoff to the wall to provide a drip edge, missing from the original.

Additionally, they have a small damp issue in the basement plant room, where water is seeping via the external emergency exit stairwell. Seems the original drainage ducting did not have any rodding points so has blocked with ten years of accumulated stuff.

And all of these problems are down to lack of oversight by the on-site project manager during the build.

When I last chatted with them. apparently, the current estimate is in excess of £150k. Lucky the insurance is paying.

Toodle pip]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18173 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18173 Mon, 12 Aug 2024 12:10:24 +0100 john.connett
It would probably be possible to produce something using a https://thepihut.com/products/adafruit-pt1000-rtd-temperature-sensor-amplifier-max31865-ada3648" >PT1000 RTD Temperature Sensor Amplifier, https://thepihut.com/products/adafruit-ds3502-i2c-digital-10k-potentiometer-breakout-ada4286" >DS3502 I2C Digital 10K Potentiometer and a Raspberry Pi Peco or similar if I possessed the necessary making skills.

However, I would prefer a ready made device that wouldn’t frighten a heating installer!

Any suggestions?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18146 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18146 Sun, 16 Jun 2024 08:17:32 +0100 blubb
I am planning the insulation of the roof for a retrofit 1927 house. The idea is to use 75 mm PIR insulation between rafters (100 mm) leaving a 25 mm gap for ventilation, and another 75 mm on top of the rafters. The printout of the structures from Ubakus are attached.

Three questions:

- where to put the vapour barrier? On the inside before the first PIR layer (probably the right thing to do), or between the two PIR layers (much easier to install)?

- which vapour barrier membrane to use? I was thinking Riwega USB Micro 100/20, but open to suggestions

- any general problems with this setup?

Many thanks in advance!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18171 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18171 Fri, 09 Aug 2024 12:14:27 +0100 Cliff Pope We are now awaiting a site visit from the installation company, who will do a flow test, take samples for basic testing of water quality, and install the well-head apparatus and pop the pump and cable down the hole attached to about 100 metres of pipe.

Standard procedure in open fields is now to dig a trench, but our route has to go down a wood , quite close to a lot of fairly mature trees. I'm a bit concerned about the possible damage to tree roots - apparently the formula is don't cut roots closer than 5 X Diameter of trunk at the base, which would necessitate hand excavation around every tree the pipe passes, and feeding the pipe under all the roots it crosses.
Chatting to the engineer who visited, he suggested instead just taking the pipe down the middle of an old and thick hedge and burying it in the dead leaves and humus at the bottom, which runs virtually all the way. He says that will easily be free from any risk of freezing.

Our grown-up children say that is risky, and it should be trenched regardless of cost, which of course they will not be paying for.

Any thoughts, observations, experience anyone?

(I've also discovered that the Earth is pretty uniformly at about 12 degrees C 70 metres down, regardless of season because the heat comes from the Core, not the Sun. So the water being pumped down the pipe will surely be at about 10 degrees to start with?)]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18170 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18170 Mon, 05 Aug 2024 08:09:10 +0100 do_discimus The party wall is on the left. Rear elevation faces east.
Our bathroom is above the new toilet. Obviously, the new toilet has to be ventilated but I'd like to improve the ventilation to the bathroom as well. Currently, we have the window almost permanently open and even doing that we get some mould on the artex ceiling each winter. Bathroom window is new. Bathroom is small, without much external wall available, see photos ->https://drive.google.com/drive/folders/1GAp-K4Xne4EMYHQX0LMeMWi7KSlujqBG?usp=drive_link
I have several thoughts and would appreciate any advice.
1. Simplest option is basic extraction fans for both rooms, through the wall. I understand single room MVHR isn't very effective at HR, and can produce a cold draught, so have dismissed that. For extraction, I've seen iCON 15 recommended for the iris shutter design. Anything else to recommend?
1a. Issue is finding enough wall to fit it in the bathroom. Any thoughts on how much wall is needed to put the hole through without tangling with the window frame? We've got 245 mm to the reveal edge on the right and 260 mm on the left next to the shower. Also, outside is currently tile hung on the right but we have planning permission to replace that with insulated weatherboard above the extension roof. Left side is brick cavity wall. Could possibly go through the ceiling and out the soffit. Very tight loft access, though.
1b. I think the new toilet extraction will need to go through the current rear elevation into either the extension, or the cavity in the extension wall, turn 90 degrees left, and out the extension side elevation. Are tight bends in very short duct runs okay? This will be right on our neighbours fence - bit concerned about ponging them!
2. Alternative is ducting both rooms out via a MVHR unit. The rooms are linked by the SVP. Issues are:
Cost is £1000s rather than £100s. Will save a bit of heating but is it anywhere near worth it? House is not draughty, but won't be anywhere near airtight, and is not that well insulated.
Are there MVHR units designed for this type of application. Would want extremely low background volume but decent boost triggered by bathroom humidity and toilet light switch.
Does it need sophisticated calculations or can you just have two extraction points from wet rooms and 1/2 inlets in other upstairs rooms (ducted through the loft)?
3. Are there other options. I've read about dMVHR with ducted extraction, like BluMartin, but I don't think our layout works well and, again, it's £££.
Thanks for any thoughts.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18164 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18164 Fri, 19 Jul 2024 14:05:36 +0100 Rex
I have a Ideal Standard Ceraplan B7892AA mixer tap on the bath (https://www.cityplumbing.co.uk/p/ideal-standard-ceraplan-dual-control-2-tap-hole-bath-shower-mixer-with-shower-kit-b7892aa/p/386326)

Even with softened water, the taps are becoming more and more difficult to turn. I have removed the tap and quite easily dismantled the hot side, cleaned and lube and it works fine.

The cold side is really difficult to turn but removal is proving to be a challenge. I have managed to round out the brass female Allen socket inside the lever so now, am unable to remove it.

Any suggestions on how to remove the Allen key and subsequently, the lever.

Thanks and toodle pip

Rex]]>