Annker

Ah, good to hear. You have the very same set up as myself.

Yeah I'm not 100% sure. Both my AI's reckon fitting a male tapered into to female parallel is commonly done and acceptable practice, below may be nonsense but this is what it spat out when asked: "The R-into-Rp arrangement is genuinely standard — that part is correct. A tapered male (BSPT/R) screwing into a parallel female (BSPP/Rp), sealed with PTFE or a thread sealant, is explicitly permitted under BS 21 / ISO 7-1 and is honestly the most common pressure-tight joint in UK domestic plumbing — most valves, boilers, and radiator tails are connected exactly this way. So mechanically, there's nothing wrong with that combination in general." Admittably the instructions for the valve specifically said not to use tapered threads, however it also made a few contradictory statements. In the end I could thread male tapered fittings entirely into the female parallel ports without any friction or stress; with the addition of Lock tight 55 these joints have passed 5.5 Bar wet pressure test and current not weeping. and will hopefully remain that way. I always have in my head that the leak risk will be less where fewer joints are used, so yes these Hep2o couplers are tapered, but they get made straight onto Hep2o pipework so it's six of one......

Below is my piping arrangement. All bathrooms systems have been wet pressure tested and seems dry and holding pressure.

Thanks @Nickfromwales and @SimonD for your replies. So I had done a bit of research before you replied and what I gathered is that there are no hard and fast rules when it comes to mixing thread types, and valve manufacturers don't seem to follow any strict protocol either! Basically the only certainly I could find was that fitting that you find on flexi type fittings, female 1/2" BSPP with rubber washer, shouldn't need any thread sealer, as Nicks says just watch that you don't over tighten and strip the washer. What I found useful is that the best thing to do firstly, is dry thread fittings together to see what works. I found that the tapered fittings I wanted to use, threaded into the female BSPP ports on the valve just fine, and certainly were not going to stress the port. In that instance wrapping them in Locktight 55 made a great seal. My supply pipework is Hep2o so I wanted to adapt to that from the valve ports with as few fittings as possible. These male and female couplers facilitated that so were my choice of fitting. It was an effort to confirm the thread type on these fittings, I couldn't find it published anywhere by Hep2o, so I had to determine it myself in hand. The males are BSPT but the female are BSSP, apparently that is typical of these type of fittings.

I have been driven up the wall trying to figure out how to connect pipework to a Crosswater Fusion concealed shower valve. To my mind the installation instructions contradict themselves and I'd appreciate to hear a more qualified interpretation than my own (I'm a Carpenter not a Engineer of any description) The valve has: G 3/4" (BSPP) female shower head port. There is no seat for a rubber seal to sit in this port (and none show on the diagram) G 3/4" (BSPP) male H&C inlet ports. Rubber edged gauze washer/filter are required to be installed on the ports The instruction specifically state: Make all pipe connections using a proprietary thread sealer Do not use tapered threaded adaptors My understanding is that a female port (where a rubber seal and seat for that seal is absent) requires the mating male to be tapered thread (BSPT) and wrapped with thread sealer to make the joint; and where the male ports have a rubber edge filter provides the seal then using thread sealer (Locktight 55 cord for example) may hinder making the joint. If that understanding is correct then the instruction are surely contradictory?

So the time has arrived to overcome this problematic detail. The solution below while not ideal aims to at least compartmentalise any shortcomings and keep the wall stud buildups safe from condensation risk: Detail is as follows below and as per attached photos of the mock up : Staple a ~200mm wide perimeter strip of intello AVCL along the top plate of the studded walls Install overboard insulation (60mm PIR board) Install main intello AVCL sheet over PIR board and tape it to intello perimeter strip. Apply air tight paint to junctions/corners within joist voids and pockets Install Rockwool batt within joist voids and pockets Appreciate any critique of my detail. Its a bit of a work around but should be easy to implement and perform reasonably well.

Will do and thanks again for all your input. Received great advice from yourself and other here, and confident I have a good understanding of the principles at work.

Thought I'd do a photo dump of some the onsite installation of the details discussed and generously advised on by some of the member here. Just some notes of interest if you are doing a similar job: Lime parge coat. Absolutely brilliant base before doing anything. Fast to apply, inexpensive and It has sealed up the walls greatly. What I have also noticed is the complete lack of any insects, mold or any living organism on the walls, I'm assumed this is due to the dryness and alkaline nature of lime. Pro clima Tescon tape. Not convinced how well this tape will stay adhere to masonry over decades, stick better to timber and best to membranes so assemble it around joist ends accordingly. And get the primer as it greatly increases the bond. Airtightness of studded walls units: I build the wall studs in situ, and before I installed the individual studs I ensured that the floor/ceiling to sole/head plate junctions were airtight. I used a combo of Illbruck FM330 and tapes. I think having a compartilization model in mind is useful so if there are any individual air leaks into the build-up they wont aggregated from wall to wall, cellar to 1st floor, etc. Insulation will be Rockwool as recommended by @Iceverge I also considered using a glass mineral wool, probably also suitable and less expensive but I have better confidence that RW will sag less in the fullness of time

Yes, typically they all quote D50 and some then quote a few other common DT's. But regardless I compared all against D50

Thanks John, that makes sense.

Hi Gus, To my mind this is not the issue, as I am comparing one cast iron radiator section against another. I called CIRC and as expected they can't give a specific reason why their section is upwards of 25% more efficient than all others, but they can say that no customer has raised this issue before. Is it just my experience or do the majority of building product suppliers in the UK seem clueless about their products. Anyway, as you also suggest I think if I use CIRC it is wise to oversize. My AI assistant summarises as such: Bottom line: With an ASHP, the risk profile is asymmetric. Undersized radiators force higher flow temperatures and reduce efficiency. Oversized radiators allow lower flow temperatures and improve efficiency. If you must err, err on the side of larger. Sizing to Paladin/Carron figures while buying from CIRC is a sensible, low-risk strategy. Worst case: you've got slightly more efficient heating and spent a bit more on radiators. Best case: you've sized correctly.

I've also noticed that CIRC state that a 4 column 760x1310 has an output of 2400W; where as their 3 column 745x1310 has an output of 2403W. A smaller section with one less column having a greater(albeit slightly) output surely cannot be correct or am I missing something?

Adds a bit more context that the Cast iron radiator centre are claiming that their 745mm high 3 column section has greater output than the Stelrad 760mm high 4 column section. It just doesn't seem likely to me. The thing is that CIRC seem to be a lot less expensive than all other suppliers, even if in reality you need to size up from their performance tables. I just want to make sure I get genuine performance figures from them.

Well that's what I'm assuming also; that is given that the designs, or material used are not significantly different, the outputs should be more or less the same. So the question is whether 4/5 brands are understating the performance of their product or one brand is overstating their performance. The latter seems more likely. AI suggested that I request their BS EN 442 test documentation to verify the claim output. I will do that tomorrow and imagine more than likely be met with silence.

I'm looking to buy cast iron radiators to install downstairs in a victorian renovation. Cast iron radiator centre are a supplier that seem to be competitively priced, if not one of the cheapest suppliers on the market. A potential catch which I am trying to resolve is the accuracy of their claimed performance (watts). I asked AI to compile a table and it illustrates as I thought, that CIRC claim their sections put out ~25% to 30% more heat than most other brands. As these sections are pretty much the same design, and I imagine are produced from same material, across all brands it seem like a claim worth verifying. Has anyone ever had the similar query? The heating system will be ASHP so I'm keen to match the respective heat loss figures for each room accurately and Obviously I don't want to end up with undersized rads. . 3-Column Cast Iron Radiator Output Comparison (~745-750mm Height) Per-Section Output @ ΔT50 Manufacturer Model Height Watts/Section Cast Iron Radiator Centre (CIRC) Traditional Victorian 3-Col 745mm 115W Shelbourne (CI Radiators 4u) 3-Column 745mm 86W Paladin Victoriana 3-Col 745mm 86W Arroll Neo-Classic 750 745mm 92W Carron Victorian 3-Col 745mm 80W

Interesting, I wasn't aware such slim lights were available. I should have clearer that I have a somewhat specific light design intent, wrt downlighters I want trimless, small diameter and in some instances directional. For what I have seen ticking them boxes means a fitting with a min depth of ~90mm As aside on a previous project I worked with John Cullen Lighting, they were client appointed and initially I thought Lighting design was a makey uppy discipline to extract money out of wealthy home builders but I learnt a lot from them and a good lighting design certainly elevates a project to the high end.

Its a retro fit/renovation. I think it would be near impossible to seal the perimeter of the VCL if it was fitted above the joists, and also more difficulty to fit the insulation to be laid between the joists. Photo below for reference, as you can see its very easy for me to fit the vcl from below. I have a thread going on IWI, my design was largely gathered from very useful info received on the forum and I will updated it once that phase of works is complete

Yes this is a good solution for me, fully constructed boxes probably aren't necessary just need some bit of background to taped the vcl to

Have you a link to lights that small, sounds like a great option if required. I'm afraid shallowest light I'm using is ~90mm

In summary I am fitting an intello plus AVCL to 1st floor ceiling joists, these rooms will have downlights fitted in the ceiling which are about 120mm in length. I cannot create a service void below the AVCL to accommodate the downlights, therefore they will be located within the ceiling joist void, hence above the level of the AVCL. There is an off the shelf solution like these however I do not see any mention of them being used by builders on this forum. I am a carpenter so I could make plywood boxes into which the AVCL is folded up into. I'm sure this must be a common detail but I can't find much detail on solutions so keen to hear what others have done to maintain the air tight layer in this situation.

@ProDave Hopefully the manufacturers have considered that but I guess only practical "testing" will confirm. My initial plan was to run the horizontal soil from the frame at/above floor level; as opposed to below floor level within the joist void. Therefore avoiding any rearrangement of the joist solid bridging. However, from the image of the frame I noticed that the short vertical outlet attached to the frame appears longer than those on say Geberit frames. Rather than assuming that vertical outlet could be cut back to permit running the horizontal pipe above floor level I decided to call the Vitra tech dept. They didn't provide a definitive response but suggested that frame may benefit from the longer drop provided from that longer vertical outlet. Its frustratingly all too common to hear manufactures giving ambiguous advice regarding how their products perform or should be installed.