Jason213

I thought I would update this thread. So, after the cold spell the condensation on the felt did disappear. I'm not changing to rigid board insulation, maybe that was a mad plan! I have also installed 50 felt vents, which should help! The other thing I didn't mention was mould on the ceilings in the rooms against the external walls (only those being slept in and not the gable ends). I believe this is because the vapour barrier behind the walls is folded to be above the ceiling. That happens to be where the least insulation is too! Seeing the attached pics, you can see how wet it is under the green plastic (even with the warm winter weather). Is this just lazy builders doing that? Either way, I've cut back the plastic as per the second pic.

Hi, yes they were left dangling and there were unused roof vents so connected to those. Our en-suite isn't being used at the moment, due to it being re-tiled, so we're only using the main bathroom. In terms of the diagram above, the outer wall is the same height as the inner. I think I'll not put rigid board insulation in due to your advice.

Like these? https://www.ebay.co.uk/itm/191857131873? I can't find them on screwfix, but they seem a great idea!

Thanks for the replies. I've attached a pic how the insulation was before I pulled it back. I don't really think it was blocking the vents at the eves anyway. If I did use rigid insulation, should there be a plastic membrane underneath against the plasterboard? My thinking was it would give better insulation at the edges to stop cold bridging to the rooms below. Also, I think the extractors connecting to the loft haven't helped, so I might connect them to the soffits again. I'm not sure how a 100mm pipe will fit into a cut in the soffits, as I'm sure it's not even 100mm wide. Or is leaving this loose in the soffits ok? Also to add, in the pic you can see where the wood is stained. I'm guessing this isn't the first time this has happened:

Hi All, after getting the xmas decs down the other week I noticed the loft has a huge amount of condensation on the felt. The house is a 2017 new build, and I installed loft zone flooring in the centre two years ago with adequate ventilation under the floor. Slightly worried, I decided to pull back the insulation at the eves to ensure adequate ventilation (it wasn't bad in the first place). I did check the soffits, and they are the vented type with a grille along the entire length. Is this common, or shouldn't there be any condensation at all? The other thing I did at the start of the year, is connect the bathroom and ensuite fans to the roof vents (rather than going into the soffits - it was just left loose a blowing in there). This was because of a failed extractor, so installed inline fans which are brilliant at getting rid of steam from showers! However, on noticing the condensation I've disconnected one of the pipes, so it is sucking air out of the loft to try and dry it. Which is helping a bit, but still wet after a week. I have asked around, and quite a few people I know (not on our estate) have wet lofts due to the very cold, and non-windy conditions. I'm really just after your opinion if this is a problem? Secondly, I think I've decided to strip out some of the loose insulation and put rigid board insulation (80mm or 100mm) at the eves to stop cold-bridging to the rooms below (as we've had some mould at the edges in the bedrooms that are slept in). Is this a good idea? Thanks!

Hi Thanks for the replies. @ Marvin. Thanks for the data, so 10kw array would have produced approx just under 11kwh in Dec2020. So that, with adequate 3 day storage, would cover my current electrical needs. @Benguela. Sorry I meant SEG For an EV, I can't justify the huge price tags at the moment, whereas my car still has lots of life left in it. So, in summary I need to decide: Go for a maximum array, with many DC batteries but an inverter limited to the max export rate (3.86 kw? i think). Downsides: No power outage cover, and won't supply peak power Upsides: No DNO application, theoretically cheaper, Conclusion: excess power can still be put into heating/hot water (SunAmp) or cooling if required, and then export at the limited rate. However in the summer months I'm sure lots of energy will be lost (without an EV). Go for AC batteries, Downsides: A DNO application, higher cost, larger inverter Upsides: Power outage option, export what I don't need and cant' store. I think I need to look at the DNO application, as I prefer the later option (until I find out the cost). So it's the G99 form for SSEN, although this is very confusing to fill out.

Hi everyone I’ve been thinking and reading about solar panels for some time, and to be honest I’ve found it a bit of a minefield of information. I haven’t started contacting suppliers/installers yet as I want to know what I want to achieve before getting quotes in, although I have registered with solartogether.co.uk. My family: 2 adults, and 2 young children (1 and 3). No EV yet.. just two diesel cars and will probably change to one EV in 3-5 years time. Mrs and kids are home by 4pm 3 days per week and home the rest of the time (apart from me working FT). Current house: New build house built 2017 (120 sq mtr) in the South East (GU32 post code). Combi boiler (gas 35 kw) for hot water and heating. EPC rating B (84) - Air permeability 4.4 m³/h.m² (as tested) Well insulated with additional loft insulation which I have done. Air con installed, which can also heat as well as cool. The house roof is 8.5mtrs wide with no shading and faces SSSW as below (this could hold 7x2 rows). We also have a double garage facing the same orientation, which could hold a second array. That is 6.5 mtrs wide – I’m not sure if it could fit 5x2 rows, but definitely could fit 5 panels. Current Energy Usage Elec usage daily: Average 8.46 kwh per day, (max 18 kwh) (5% of the time 12 kwh or more since we’ve lived here) (5% of the time 4.5 kwh or less) Gas usage daily: Average 20.6 kwh per day (average over the year) (38 kwh in all the December’s) (Max 67 kwh) (5% of the time 45 kwh or more) Based on a 540watt panels, the house could hold 14 panels totalling 7.5kw array The garage could hold 2.7kw array I would also like it to work in a power cut. Now, where do I start? My budget would be £15-20k tops for panels and batteries. Ultimately, I want the biggest array possible when the scaffolding is up hence the 500+ watt panels, and ultimately be as off grid as possible. I would probably want to register for feed in tariff payments, just so that is set up. Looking at our usage, and (https://re.jrc.ec.europa.eu/pvg_tools/en/) a 7.5kw array could produce 9.3 kwh in December, rising to 31.5kwh in June. So almost cover all of our current electricity use for the majority of the year on average. If we got a 10kw array (using the garage aswell), that would be 12 kwh in December, rising to 42kwh in June. The surplus, I would look into storing hot water, Elec heating/cooling for the house and a future EV. I’m not sure if it’s possible to install a hot water tank due to the weight, although do have the space upstairs. So I like the idea of something like SunAmp. But I accept this is the next step after panels and batteries. I also like the idea of topping up on a cheaper night time tariff if required (but may not be required with such a large array). What systems do people recommend? I liked the idea of a Tesla Power Wall, but I don’t think I can have more than one due to needing a 3 phase? Secondly, they are completely unavailable now. I’ve read Solar Edge only works with their own components, so you’re tied to them if you go that route. I don’t have a clue what the best panels or inverter are. What size batteries do you think I would require? Obviously the larger the better, but something like 25 kwh (i.e. 3 days average usage)? I’m aware some people say do it in stages (panels, then batteries), but I would rather it all installed and working in one hit. I would also want to give me as much power as possible during winter when top up from the grid is inevitable. Thanks!

Hi all, I've joined to learn a bit more about self build. Although still a dream for me, our local council is releasing 'affordable' plots of land for 12 self builders with a local connection. I'm just trying to research if it's even possible. Jason