Dreadnaught

What purpose does the timber inside the stud serve at a door frame? Is it just to give something to screw in to, as I had assumed? Or is it to add rigidity, to allow for a heavy door on the hinge side? And/or to stop vibration as a door slams?

That's an interesting approach. Another way to make a box could be to use another section of track as a cloak for the stud, as is used with wider spans.

Thanks @nod. What dimension timbers should I buy for 70mm C-studs?

Thanks @Conor. The fact that they are treated and you are using them inside your dwelling isn't a concern?

I am currently doing my MF internal walls, GYPROC Metal C.Stud 70S50 (70mm). What have people used as the timber piece in the uprights. I tried Travis Perkin's C16 38mm x 63mm x 2.4m but it doesn't quite fit. Otherwise I can only find online treated battens of 50 x 25mm (i.e. roofing battens) or expensive PSE at 44 x 22.5 mm. What timber have others used in their doorways? @nod?

Good point. MVHR ventilation gaps under doors can undo a lot of good work. For the study/TV-room, I am going to move the ventilation gap from underneath the door to a new grill-vent through a cupboard in to a quiet neighbouring corridor. The door will be a snug fit.

@Moonshine, I am using MF internal walls rather than timber stud. Is there still a sufficient impedance mismatch between concrete and steel/MF to make the use of acoustic-isolation strip largely redundant? (Mine is new-build bungalow and the reason I ask is that I am just now starting on my internal wall installation and wondering whether to order some acoustic-isolation strip.) Sorry to resurrect an old thread.

It's unlikely to be a problem I would guess for that thickness. Many insulation companies will do an interstitial condensation assessment free-of-charge. I had one done for the roof build up when I decided to add another layer of insulation underneath. I added an extra 100mm of woodfibre insulation beneath a warm roof of 200mm of PIR. It wasn't a problem. Good airtightness will help of course as the main source of interstitial condensation is warm moist air migrating in to the fabric from within the building.

More tuppence. If you go the timber-frame route, make friends with your frame designer. He will have a wealth of knowledge about what's buildable and how to make the frame simpler. Don't fall for the mistake of letting the frame designer deal only with your builder or frame manufacturing company. Your builder may sign the contract with the designer and may well pay his bill at the end of the day, but you should have long discussions with the designer yourself both so that you can learn and that your priorities will end up being incorporated in the frame design. This is what I did. If I build another house (and I may), I will change the process. I will first choose and retain a frame designer myself (probably the same one as I used this time as we got on well) and design the dwelling with him (plus an architect for the aesthetic input). And then take the design to a timber frame manufacturer to make and install it all on site.

My tuppence worth. I agree with @kommando. I have restricted access, albeit only 80 metres worth. And could not have a crane on site too. My frame builder, which I chose to be local, simply had the frame designer design smaller panels, which were made in the factory and brought to site on a smaller lorry and then handballed in to position with dollies and few burly lads. It went up easily.

Are you aware that you can contact Vaillant directly and they will provide a custom system design for your particular setup. That's what I have done. They ask for the name of your Vaillant adviser and I just used the name of the local area rep without having ever spoke to him. They did not seem to mind. (In my case, I have my heat pump and UniTower on site. I have done the physical installation of the heat pump only so far. I have not installed the UniTower yet. Nor have I made the hydraulic and electrical connections for the heat pump, although I have bought the parts for the hydraulic connection.)

By joining to the neighbour's garage, is there any risk that your house might change its "estate-agent" description from "detached" to "linked detached" and thus affect its perceived attractiveness to a future buyer? Such things shouldn't of course make any difference but sometimes do. Or did I get the wrong end of the stick and your house will be unaffected.

Yes. In the event of freezing weather and the realistic prospect of a power cut lasting 24-hours or more, I'd probably just turn the isolation valves and disconnect the pipes to the heat pump and let it drain. I have a ground-mounted installation which isn't up against a wall so simple to do with easy access. I will have a short length of 28mm Hep2O pipe (suitably well insulated and protected from UV) connecting the heat pump to the duo insulated pipe that emerges from the ground so won't even need a spanner, just a Hep2O key.

Haha, no comment but we each choose our own level of risk according to our own comfort levels 😄 Ah yes, I was just now buying the 28mm connection bits for mine (and have 32mm duo insulated pipe under my raft foundation).

Oh, no I don't. No idea at all. In reality, the probability of a power cut lasting 24h-duration is remote at any time. And I am a natural risk taker

Yes, I am in the south (Cambridge) and, after reading this very helpful thread and some of the links presented, especially that from Graham Hendra, I have decided to do without both when I commission my own heat pump. Then I shall pray that there isn't a power cut that lasts for more than 24h which coincides with freezing weather.

Yes, had my electrician on site a few days ago on this precise issue. He said the same. Either 450mm down or surface mounted (even just above the soil level) but not in between.

I found this YouTube video informative on the subject:

In case anyone is interested, I just received one of these, plumbed it in, and it really does work. Impressed! I ordered it as a test and have installed it on my temporary site toilet. Will probably now use it on the finished ones when I get to that stage. The model I bought is Samodra Minimalist Bidet, dual nozzle. I paid under £20 for it. Happy to answer questions if there are any.

I have purchased rails for automatic curtains from Somfy, which I will install flush to the ceiling (I am still at First Fix so they are not installed yet). I am holding off buying the motors that fit the tracks until the company releases ones that use the Matter Standard.

I bought my nine rooflights from: https://roof-maker.co.uk in Leicester. It wasn't entirely plain sailing but I am content with the result. Happy to provide more of my story if you like.

Good to hear. Not tempted by one yourself?

Buy a normal toilet and add one of these? https://www.samodrahome.com/collections/bidet-attachment/products/samodra-minimalist-bidet?variant=40198313509062 They are available on AliExpress, Wish, eBay, etc. If you search, you can find lefthanded ones too. I don't have one but its a solution I am considering.

I am puzzling over biocides for my central heating system. My system will be UFH and a ASHP, brand-new plastic pipes and with no radiators. Its a low temperature-system and so might be prone to bacterial growth and biofilm formation. But on the other hand, tap water contains chlorine. Reading the Vaillant manual for my UniTower (an all-in-one UVC) it says: "Do not use any unsuitable antifreeze and corrosion inhibitors, biocides or sealants". And then does not list any biocides on its approved list. So should a biocide be added to an UFH system or not I wonder? What have others done?

@ProDave, did you ever get to the bottom of this? I am currently mulling what additives I will need to add to my heating circuit, if any, when I set it all up.