MJNewton

It's up to you but you've got to live with yourself and I'd always play with a straight bat when it comes to issues of honesty. What goes around comes around and all that. At least you've got a slight chance of seeking a remedy here, whereas your buyer wouldn't have any (unless they tried to persue you of course!).

I try and remind myself of that whenever I fail to do something perfectly or, worse still, a tradesman I'm paying for does instead! I also try and remember there are a million other houses out there with less-than-perfect aspects to them and they somehow find a way to live a perfectly functional life without losing sleep.. ?

Yes, I was thinking plaster too. The green might be a result of flux on the plumbers hands during installation. If you clean it up and tape a sandwich bag around it you'll soon find out if anything's coming out.

Aree you sure that's a leak? I wasn't sure it necessarily looks like one given where the white stuff is/isn't. Obviously clean it up and see if it comes back.. Automatic air vents can often be sealed closed but your cap looks like it's got a hole so it might not be possible.

Yes, but not usually that deep so could be emptied in the right (wrong) circumstances. The sewer smells would still be contained though (or rather would be blown out of the flue, via the burner!).

I don't think there are building regs related to room vent locations, however I would imagine the manufacturer of the fan unit has design guides that cover the subject and it'd be hard to argue against them. What make is it?

Okay, thanks, will give it a go. I've got some needle files. Gulp.

Okay thanks. Just to confirm, this stuff? I notice it mentions static cracks and doesn't specifically mention flexible which seems necessary in this instance if it's going to keep moving with the seasons? Point noted about opening the crack up. When you said it previously my heart sank as I knew it'd feel wrong when it comes to doing it but deep down I'd know (or at least hope!) it's right.

I never did get round to sorting these cracks out but I've got interested in them again as last week I noticed they were much more visible ('blacker') and assumed they'd got worse... Today however they're practically invisible. The difference I'm sure is down to the -5C of last week and +9C today. If there's temperature-related expansion/contraction going on (noting it's a timber flat roof with a large opening so plenty of potential for movement) then hard filler/plaster is likely to be unsuccessful. @nodyou mentioned 'good quality flexible filler' - is there anything in paeticular you had in mind? It's a minefield out there with too many choices... Edit: I'm not necessarily after 'invisible', there's just something about a black crack that kind of says 'falling down' to me; they just seem particularly unsightly against an otherwise perfectly smooth and bright white ceiling and whilst you can't see it from all angles the sofa just happens to be the prime viewing location...

I only intended it to be a joke..

What's the setting actually a measure of? The reason I ask is that on my unit it can't be adjusted (not even visible) but it's never kicked in despite the outside temperature regularly sitting at -4C. I've put this down to the fact that the exhaust air in those situations has been, say, +6C and so the heat exchanger itself is still sitting above zero hence not at risk of frosting up.

Oh okay - good! I thought I'd come up with an idea that would revolutionise the world of MVHR. Hopefully still time to cancel my patent application...

Our Titon MVHR unit has a 'setback' feature whereby, if you apply 240V to one of its input it'll reduce the flow+extract rate to halfway between minimum and the 'normal' rate. I believe it is intended to be used when away from the property however I was wondering if it could find utility overnight? The system works really well and isn't noisy, however I am mindful that in our less-than-optimum house (in terms of insulation, airtightness) it could be advantageous to reduce operating losses whereever possible and whilst it might be a compromise on performance to do this during the day I figured at night our water-producing activities are much reduced? Sure, we're still breathing but we're not bathing, cooking etc and we'd still be getting some level of ventilation. Just thought I'd share the idea with the panel and see what you think. I already control the unit with a Pi and some 'smart' relays so adding another input wouldn't be too difficult, and I suppose in addition to limiting it to nighttime I could activate the setback only when outside temperatures are particularly low and corresponding heat loss high.

I'm not religious but I must admit I'm tempted to start praying for his return.

Now that I've said this I decided to be brave and go back to page 1 and found that it only actually started in September 2020! The infamous 'Covid-19/All things Coronavirus' thread, started back in January 2020, is now at 353 pages. A quick comparison reveals that Zoot's extension has created over a quarter of the posts in half the time which is really quite remarkable for one of the most significant and contentious global events in modern history (the pandemic, not the extension...). Here's hoping the vaccines continue to work against more than just what they were originally designed for.

I don't dare go back to page 1 to check but given we're on page 79 then, yes, an early-90s start date sounds about right.

If you've lost the plot I'm afraid you'll have to go back to the beginning. Don't worry about missing out though; we'll still all be here.

Could well be, and intended to represent the 'ambient' temperature of the surroundings. 5.9°C sounds reasonable for a cold roof space with an outside temperature of 3.4°C. (Mine is currently 4.1°C in the loft, 1.3°C outside so broadly similar) With a supply:extract ratio of 13.1°C:17.8°C that gives a 74% heat recovery efficiency which whilst on the low side is still within the realms of what might expect, particularly if the flow is on the high side (harder to recover the heat) and the loft is cold. Tweaking the flow down a bit and adding some insulation to the unit might help. Also, make sure any ducting in the loft is insulated too - I imagine your house isn't actually at 17.8°C, particularly at ceiling level, and so there's some heat loss along the way in the extract ducting. All very common for a retrofit in my view. Incidentally, whilst it'd be worth experimenting to see if you can up the efficiency do remind yourself that even 13.1°C is considerably better than the 3.4°C that you'd have coming through window trickle vents that you otherwise should have!

That could well be it - the 'decent standard' may well have resulted in less natural background ventilation in that room. Completely disagree with you their Zoot. Behind that question lies the answer to your problem. There's no magic going on here - it's just scientific laws being followed and whilst you might want to believe they don't apply to your part of the world I'm afraid there's no escaping the fact that they do.

I wasn't suggesting Velux as such, but would be expecting 100% blackout from whoever/wherever I did buy one from.

I haven't personally experienced flat rooflight blackout blinds but for what it's worth I did once have a blackout blind in a Velux window and it never ceased to amaze me how perfect it was. Regularly I would open it in the morning and be really quite shocked going from absolute pitch black to daylight. I'm assuming ones for flat rooflights would be just as effective as it's the side rails required to defeat gravity that is the key to their success.

If you're not quite sure - or just what to keep costs as low as possible - keep en eye on eBay as MVHR units often come up for sale at half retail price or less. Many are brand new or at least 'as new' but might be missing packaging etc and without warranty. There's definitely money to be saved. Mine had been fitted but never used, as part of a development of multiple houses but they hadn't met the spec so they were all ripped out and replaced with the next size up. The bloke doing the reinstall action stuck them all on eBay for just a few hundred each. I reckon I'd still get the manufacturers warranty as the serial plate is date stamped so I could easily claim it was fitted prior to me moving in hence no receipt.

Yes, thanks for this. We've got a Titon MVHR which uses ebm-papst fans and so chances are there are a number of other units that also do.

It gives you a baseline. When the condensation returns you can compare the readings and see what's different - higher RH? Lower internal temp? Lower external temp?

It could fall under the general requirement of: 134.1.1 ERECTION AND INITIAL VERIFICATION OF ELECTRICAL INSTALLATIONS Good workmanship by one or more skilled or instructed persons and proper materials shall be used in the erection of the electrical installation. The installation of electrical equipment shall take account of manufacturers' instructions. If the manufacturers' instructions say that you should fit an isolator then I suppose it's just down to you to justify not taking them into account? The circumstances might dictate the signifance of having to do so eg there might need to be a particularly strong reason if someone broke their neck falling off a stepladder because they were trying to clean/unblock the fan in the dark as their only means of isolation was via the circuit breaker of the lighting circuit it was attached to.