jayc89

We have a wide south-facing window, which I'm having to keep the curtains closed on most of the day to avoid the sun being directly in my eyes whilst working. Got me thinking, must be a pretty good aspect for a PV array...

We're installing MVHR in our renovation. We've managed to find a couple of areas quite centrally that can be used as service voids to drop ducting down from the loft, where the unit will be, to the ground floor rooms. Our joist directions are also helpful to allow us to run that ducting between rather than over. On one side, we're able to drop down through an airing cupboard and the other side we're just going to make a stud wall between a bedroom and ensuite slightly wider to accommodate the ducts. If you're seriously considering insulation and airtightness, service voids will likely have been thought of anyway, to avoid penetrating your airtightness layer, so perhaps this could be an option for you too?

Apparently the unit is end of life, and has been replaced by the IFOS system which won't work on my boiler. Managed to find a plumbers merchant that had some old stock, will get it fitted this weekend - happy days. Fingers crossed it never fails!

Had a quote for Warmcel, 350mm deep which is coming out at approx double the cost of buying new insulation rolls. Is there any major benefit to Warmcel (or any other blown cellulose) over mineral wool, other than ease of application?

It did cross my mind, is that allowed? I'll be getting our sparky back in to connect everything up, I'm just doing the legwork.

That's what I'm thinking, but I probably screwed up by only allowing myself a 25mm service void. I don't have the space to put OSB behind the backboxes and them not protrude beyond the PB. Perhaps I just need to bite the bullet and go for drywall boxes in this room and chalk it off as experience...

I have some double-sided butyl tape so that would work! It'd be screwed into PIR though, so unlikely to grip for long? Directly behind is brick so I could use pretty long concrete screws, but they'd act as cold bridges.

I really don't like the feel on PB backboxes, was hoping to stick with the metal ones.

I have a 25mm service void, which will be finished with 12.5mm plasterboard so I plan on using 35mm backboxes, which will be secured through the sides and bottom to studs/nogs. Can't secure through the back as that's my airtight layer. I plan on getting these - https://www.screwfix.com/p/lap-2-gang-galvanised-steel-installation-boxes-35mm-10-pack/88287 - but the top/bottom/side holes look quite close to the edge of the box so I'm worried they'll be proud of the stud work around them (where the PB will sit). Am I missing a trick? That's generally the case!

In theory, taping over the PIR joints should be fine. I've done both, just out of paranoia, it also allows for a better join at junctions, IMO.

SWMBO and I both work from home, we have a relatively small room (3.5m x 2.5m) that we're turning into a shared office area, don't need loads in there, just a couple of desks as a minimum. It's in the North/West corner of the house, and the window is shaded by other parts of the house to the South so it struggles with light until the evening in the Summer and it's pretty dull the rest of the year, so we expect to have the lights on in there most of the time. We like the idea of plaster-in LED downlights (room is downstairs, so no airtightness concerns using downlights), the majority of electrical equipment has been LAP (Screwfix's own-brand) and we're relatively happy with it, they down an "anti-glare" downlight which might be an option - https://www.screwfix.com/p/lap-eclipse-fixed-fire-rated-plaster-in-downlight-white/923kj - given the space, I'm guessing we're going to need 6x. Is £13 each reasonable? Would you recommend any other type of lighting for a home office?

I have one of these - https://www.toolstation.com/dewalt-dw088k-xj-laser-level/p98428, that, a tripod and an old bit of timber to use as a measuring staff is all I've needed for internal work. Including laying a new floor slab. I'd only consider anything larger for outside groundwork etc.

Can an individual buy direct from them? Do I just sign up to their eShop?

I'm about to order my first roll of ducting, along with a couple of plenums, I guess you could consider it the start of my 1st fix - woohoo. I'm going for 50m 90mm antibacterial semi-rigid ducting, but there seems to be a vast price difference across different sites; - Paul Heat Recovery - £302.40 - BPC Ventilation - £186.16 - Plumbavent - £193.59 I'm assuming the latter two are more reasonable, is there something I've missed which explains why the first one is significantly more expensive? Is there anywhere else I should consider ordering from?

I'm putting up a suspended ceiling, which will be covered in PB. Ceiling is 3.5m x 2.5m. I have a load of 2x1 battens left over, would they be strong enough to use or would they have too much flex to support PB and skim? Or should I go the whole hog using mini joist hangers and 3x2 instead?

Anyone any suggests on what the junction between a floor void and a service void should look like? I assume having the service void continuous would allow sound to travel. I also assume there are some fire regs to consider, or is the plasterboard across the service void enough?

PV gear is a good shout too. What's the best way to keep a room in a cold loft cool during the summer months?

I have an old house, our mortar beds are actually smaller than that, probably only 5-8mm. We're also changing the windows after they were bastardised in the 70s and were advised "not to break the bond" or fix the bond where it already has been broken, so our new window openings will be in multiples half a brick's length + 8mm mortar joint. I think there are different types of brickies. Those that only know "that's how it's always done" and those who are willing to adapt and go the extra mile, so if you want to go off piste, you're best finding one of the latter.

If it's on the rental, which I agree is crazy high, why haven't the per unit prices come down in line with wholesale prices? I know there should be a few month's lag due to when it was placed in storage, but I'm talking about the last 3-4 months now.

One of my mates has been working on something similar for a good few years now - https://www.legalandgeneral.com/modular-homes/ - think they already have 4/5 developments on the go.

The bailouts shouldn't be factored into OVO's variable tariff rate though, should they? Or are they being baked into the wholesale prices by the govt. prior to reaching the suppliers?

Isn't the price per therm now lower than it was at the start of '22 and large chunks of '21 (and has been for the most of '23 so far)?

Given we're now seeing a, fairly substantial, drop in wholesale gas prices, why isn't this being reflected in household bills? I'm on OVO's variable rate tariff now and for the past 3 months I've been paying the same 9.75p/kwh of gas usage. Electricity unit price only changed once during the same period and in the wrong direction from 31.43 to 31.45p/kwh! It's like fuel prices all over again...

Perhaps a crazy idea... We have a cold loft space, hipped roof, plenty of room centrally, but drops off quite a bit towards the eaves. I plan to reinsulate it with blown cellulose and board it out. Our MVHR will also go up there, so I need to think about insulated ducting where it's not buried beneath the insulation. We currently have a 200L unvented cylinder which we occasionally run low, predominantly on Sunday's after we've washed the roast pots and everyone wants a shower (we could change our schedule but...) my suspicion is that this problem will only get worse as the kids get older, so will eventually look into a larger capacity cylinder, which wouldn't fit in its existing location. (airing cupboard). Would it be possible to make a room up there, using some stud walls, insulating them to effectively give me a plant room. All pipes etc would be ran from beneath buried in the insulation, coming up through this new room's floor. Which would avoid the need for me to think about insulated ducting etc for my MVHR, it also means I can mount my MVHR manifolds somewhere accessible opposed to beneath the insulation. I'd also have somewhere to relocate the hot water tank too, and potentially even the boiler if I wanted to. By my calcs the room would be approx 4m x 4m and the ceiling height would be around 3m, so plenty of space, whilst still allowing for ventilation across the roof timbers. Cold/freezing conditions aren't a problem as everything would either be beneath the loft insulation, or within the insulated room. What I'm not sure on is summer conditions, the slates turn the loft into an absolute oven, last year being fiercely hot, is there a risk of the services in this box room overheat, specifically the MVHR, and gas boiler, if I was to move it up there? Would the room itself need some sort of cooling/ventilation?

In an ideal world I'd get rid of the mixer and let the WC do its thing, however the WC has an override which sets the boiler flow temp to max whenever there's a call for heat from the hot water cylinder, so the mixer needs to stay in place as a safe guard, unfortunately.