SimonD

Best practise guidance now recommends against using moisture closed insulation systems on retrofit iwi. Where it is used, a ventilated cavity is recommended. If you're going to below u-value of 0.30 then you have to have a good look at cold bridging, not just interstitial condensation and moisture. If you were to go with a moisture open insulation you can fix this directly to the wall, not worry about your vcl, just air barrier. Government guidance here: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1019707/iwi-guidance.pdf

I've dug out the report @ADLIan refers to above. The link https://www.jhbrandt.net/wp-content/uploads/2014/11/ir761.pdf I'll leave you to nerd out and make your own minds up about the various components as you may see it is not all entirely intuitive.

I posted these up a little while ago giving absorption coefficients for Rockwool and Knauf acoustic insulations: https://forum.buildhub.org.uk/applications/core/interface/file/attachment.php?id=53703&key=6933e2a133c40aea7af458dc3a9054d0 https://forum.buildhub.org.uk/applications/core/interface/file/attachment.php?id=53702&key=0a4d463e77ddae0b111dc91878cb0bbe As you'll see, 50mm isn't great, better to go for 75 or 100mm in your stud wall. Having a small airgap in there is a good idea. And also as per @ADLIan the insulation only plays part of the role, it's the whole buildup that makes it work.

Unless you're on an exempt green tariff which is not capped. We're on such a tariff which is now become incredibly painful abnd way above the capped rate. I've looked at alternative suppliers and it seems to be a case of phoning around and speaking to the companies as they won't quote online.

FWIW I've used 18mm osb on my non-loadbearing stud walls to line my utility room as I'm going to be hanging lots of stuff on the walls. Upstairs I've used a load of 11mm osb to line the stud wall in the study/guestroom again to help with fixing and hanging things. I had it all left over from building the roof and tf so though I may as well use it and it does reinforce the plasterboard nicely for fixing.

Only yesterday was I reading an article in the Guardian about the cost of house renovation and extension and how you can maximise your return on investment. Sadly, there was absolutely no mention of energy performance but singled the biggest benefit being to do the bathrooms and kitchens. I wonder how long it's going to take for the priorities to change in light of this huge bump in prices? I have to say though, I abhor the focus on economic payback associated with energy performance upgrades when they actually add so much value to day to day comfort and pleasure which makes the house a much nicer place to live. I'd much prefer a basic plain kitchen and bathroom and a warm and cosy house. When will the penny drop not just for the population but the government too, I wonder?

Was it one of those place that had to be escaped in youth?

Interesting your experience here. We did our last place up with F & B in its entirety and can't say we were bowled over by the quality or finish. We used what was Ecos paints (I think now Lakeland paints?) for the next redecoration and one of the colours caused us a mega headache due to inconsistent pigmentation - it was so bad that when mixing the different pots, it went a completely different colour which looked really weird. Then when we had our two boys I used the trade Dulux diamond hardwearing whatever stuff that put up no resistance at all to the boys' tendencies to drive their hotwheels along the walls, especially when going up the stairs. This time I'm trying Auro clay paint, the white tester of which I've had on a wall and occasionally rubbed my dirty building hands over it, left it for a while and then wiped off. I've been surprisingly re-assured with this so far I'm going to let the boys loose on a test wall. Pigments are realy nice in these paints too.

The good old history of the building. I found a mixture of newspaper from 1927, the 1960s and the 1980s when pulling our place down. I wondered whether the builders had found the earlier stuff and thought that's how it's done and just copied it down the line.

Gorgeous location, nice place to be! 🙂

That's really helpful, thanks for that.

That looks great @Mr Punter. Neat profile on the hood and simple which is what I'm looking for. Did you have any issues with the internals when you removed the motor, like losing the spigot or other necessary ducting that needed to be fixed?

Good to know. Thanks for the heads up on the TD Silent. I have a Vent Axia unit going spare I thought I'd used so I'll check to compare extract data.

That's excellent, thanks

Yes, it's 29mm deep. I've also found some that's 308mm wide https://www.nationalventilation.co.uk/wp-content/uploads/2020/11/Monsoon-Rectangular-Ducting-308mm-x-29mm-Duct-Accessories.pdf Okay so I haven't completely lost it. That sounds very similar where I'd planned on using the corner in the kitchen base units to house the fan as I've ditched the idea of a corner cabinet to have some services in there instead.

Because of my kitchen design I've been looking for a kitchen extractor/cooker hood design that is similar to commercial designs in that I've got a canopy with grease/carbon filters and then ducting (29mm that goes in my service void) to a remote fan unit, that I can box in and isolate acoustically (I've even got a dedicated space available for this in my kitchen). Other than to have a commercial canopy company make a bespoke one, I've been unable to find anything like what I'm looking for. Otherwise, every other extractor seems incredibly noisy (all our previous ones have been too), and unfortunately most, if not all, are imposing on my attempted clean space and drawer/cabinet design. Even the downdraft ones seem to have fundamental flaws, like I've got to reach over my cooker to operate the controls and the motor unit ends up taking up all my under counttertop space which is designed for drawers to store all my pots and pans. If I can't find what I'm looking for above, at a push I'm thinking of a subtle cantilevered recirculating unit (that provides a low profile) - we're not having any wall hung cabinets in our kitchen. My other desperate thought is not to have a hood at all and maybe just install a single room mvhr that has a boost function for local ventilation for the kitchen. Or maybe I can gut a hood by just removing the motor & fan assembly? I've been looking for months on and off and feeling rather downheartened that I haven't found an adequate solution yet. I've left it a bit late because I'm making the kitchen right now and cutting the plywood for my drawers as I start this thread. Can any one help with some creativity here please as mine's deplete? Desperate for some ideas.

I think that was the same for Didcot, coming over the hill on the A34, or walking up on the ridgeway, the view was just something that was there.

I don't feel so sure about that. I think behind the scenes he's able to muster undue organisational influence because what he's saying plays into the hands of those who have much to gain and lose in the coming energy shift and they currently wield power. Just consider the self-inflicted damage he and the ERG helped to inflict socially, economically and politically and for what real ends?

Yes, this is the dilema. Wind generation needs to be where the wind is and this often clashes with peoples' view. Vattenfall has come under some criticism in Sweden for this. Large windfarms are being developed in non-ideal places because the ideal places are more heavily populated and develoment is resisted, not that they're anywhere near as heavily populated as here though. I've really tried, but I personally find it difficult to accept the position of those who oppose the development of onshore renewable energy because it might be an eye sore, yet want the energy on tap and to be able to consume it cheaply.

That's a good point. Interestingly I've been consuming the recent book by Helen Thompson, Disorder: Hard Times in the 21st Century which takes a fascinating and very worthwile look at energy and geopolitics and puts quite a lot of current issues into perspective.

That would certainly be a big improvement.

My concern with that would be the absorption co-efficient of the insulation. Knauf and Rockwool kindly sent me their test data a while ago and if you look at the performance of 50mm versus 75mm it's pretty significant, especially at lower frequencies (obvious caveat that the acoustic performance depends on total buildup of course). Files uploaded for reference below. Knauf Insulation Acoustic Roll - Absorption Co-efficients .pdf Absorption Coefficients of ROCKWOOL Slabs - v2 2019.pdf

Yes, it would be fine.

I'm going to be annoying here and not entirely answer your question, but instead pick up on something slightly different 😉 I notice you have acoustic insulation shown in your drawing. If you're looking for decent sound insulation within this staggered wall, I'd recommend you use a continuous roll of insulation which zig-zags behind the staggered studs. 25mm acoustic insulation isn't going to do much and with the current design you only have 8mm between staggered stud and plasterboard so too narrow to do anything. In that sense, depending on the noise levels you want to achieve, you might be better using 38 x 89 studs which are installed on 38 x 140 studs at top and bottom. You can of course go for 38 x 63 and increase the gap behind each stud using 50mm insulation but I'm not sure how quiet the wall will be. Remember though that your stud spacing will be 600c/c at each side of the staggered wall so in effect 300c/c (Just noticed PeterW already said this) Most places will supply C16 cls in my experience.

I can't seem to find actual dates. When was the microcement done? How many days has it been now? General rule of thumb for my microcement was allow to dry for 48 hours with no use. Light use only for 7 days. Do not cover and wet for 14 days. Fully cured in 28 days. Recommended Minimum application temp 11 C. Drying times are based on certain humidity/temps only. HTH