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Olf's Achievements

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  1. I'm not sure if Thermoblock would be ok for mounting TF to, but moot point if out of budget. Second best option to mitigate bridging would be perimeter insulation using phenolic.
  2. It's outside of insulation envelope, having the best insulator thee will do nothing (or close to nothing). Instead I'd think hard how to replace the kickerblock to avoid cold bridge there (and still be able to mount TF well)
  3. SF60 has 120mm thickness, so that would be equivalent to lambda (or K) of 0.29 - pretty realistic. What is not realistic is that you pay over £21/m2 for that performance (https://www.wickes.co.uk/SuperFOIL-SF60FR-Multifoil-Insulation-Roll-1500mm-x-8m/p/237123) so roughly 6 times more than wool https://www.wickes.co.uk/Knauf-Insulation-Space-Standard-Top-Up-170mm-Loft-Roll---6-47m²/p/109450 Even after adding reflective VLC (like https://passivehousesystems.co.uk/product/phs-hi-thermia-reflective-membrane/) there is a lot of change left. There are caveats to that performance though: - the quoted R takes into account surfaces and continuity of the material, the core itself is probably on par with wool at between 0.3 and 0.4 - it is reduced to 0 where attached to rafters, so with 600mm centres and 75mm wide rafter effective R drops close to 3, and probably more as it takes some distance to expand from 0 to 120, and compression reduces performance Big worry is also that their BBA certificate has been suspended https://www.bbacerts.co.uk/2022/01/07/december-2021-new-withdrawn-certificates/ Be careful, as your statement is as misleading as salesman talk: R value is not meaningless without thickness. Thermal resistance of a surface is non-zero, yet its thickness is. And even for those cases that indeed can be calculated by the equation above, R can still be better, if k changes with thickness - which frankly is the case for most of the commonly used materials: PIR and phenolic lambda improve with sheet thickness, wool performance drops.
  4. Parasitic upstairs heating is possible, but be careful here: - you seem to have large floor area and relatively small stairs opening for convection - assuming MVHR is present it will help transferring some heat - if upstairs floor is well insulated acoustically (as it should), it will block conduction - depending on what is above (you mention attic, so should be ok) you may still lose more through the roof than is delivered from the ground floor
  5. Are you planning to use any government scheme for ASHP installation, where you are at mercy of the supplier with them working hard to maximise their benefit? If not, are you planning to keep the gas or rip it out? If the former, then you have a backup and can optimise the ASHP size even better.
  6. This looks like lazy approach of the designer, just letting loopcad spit something out in no time I would: - put at least kitchen manifold (if not both) in boot room - boot room and entrance heated by runs to the other rooms only, likely still requires insulating most of the pipes (especially hot legs) - too many loops: study 1 should be enough, kitchen & living 2 - fewer loops (I ended up with 8)= shorter manifold, you may be able to reduce to 1 manifold only with simplification of supply plumbing and controls - consider spiral loops in most of the rooms: more even heat delivery, easier to lay, lower flow resistance. - as mentioned earlier no pipes under any fixed units and anywhere near the fridge in the kitchen, nor in the places in the WC (as explained earlier). The loss of heat delivery there will be compensated by towel rail. Tbh I'd run one loop for WC (hot leg incoming here) and utility, passing under the wall is not a big deal: just insulate the pipes
  7. CLS have standard (albeit Canadian) dimensions, if you fit door frame that makes a bit easier to find a matching kit.
  8. It may be, but you need a tool and extra spend on clips. Also it would have to be planned carefully to not to collide with the chairs for rebar, so I think tying to the mesh is the way to go. Not sure about your shoe size, but 15cm between the bars is enough to put a foot on 2 adjacent, you can easily go forwards and sideways, bigger issue is reversing and not stepping on the pipes Irrelevant, flow temperatures are the same. Saying that, my thinking is that rebar would help to transfer heat from the pipes attached to it initially. Mind that with pipes at insulation level, the same will happen once the heat reaches the mesh above, and considering UFH heating is all about slow and steady, it should not matter in the end. Also my thinking is that UFH pipes at mesh level should result with slightly lower losses: at 35°C flow temperature I get 25°C surface temperature. With pipes roughly in the middle of the slab I'd expect bottom of it (where it touches insulation) will also be at ~ 25°C. Pipes attached directly to the insulation means something close to the flow temperature is reached there, and so higher heat flow happens downwards. You need another layer of membrane (thinnest DPM you can find) on Celotex to stop reaction of aluminium facing with concrete, also prevent any leaks between the panels (just in case, even if foamed). As mentioned earlier, apart from compression lagging around, do install perimeter insulation to prevent bridging to the walls. Put it between DPM and the 2nd membrane, otherwise it will float away. I've seen opinions that EPS is 'soft' enough to act as both, though PIR will have better properties. Also all the services going through the slab will benefit from being wrapped in lagging And last but not least make expansion joint in any doorways, otherwise they'll form naturally. Through those places make sure UFH pipes are bent (even forcing S shape) and covered in pipe insulation, so they can move a bit within once the slab is settling.
  9. Beamshield requires void underneath, as it is beam&block system, just EPS block. The greatest drawback is need for protection from damage during further stages of the build. From other practical issues it may be the supply: finding local casting company that collaborates with them (though there are similar alternative systems), volume required (whole house is more likely to succeed, my extension failed to fill an artic) and competition from volume builders if present around (one of the companies I talked with at some stage pulled out, as their whole output was sucked by major developer). But in principle yes, it's a no brainer. Though so is single skin externally insulated wall as used throughout Europe, yet cavity rules
  10. Yeah, I figured that! Hence I'm thinking about employing shmbo to do the levelling, and from that perspective a roller on a stick is more manageable.
  11. Is it worth investing in spiked roller, or will any agitation (trowel?) be sufficient to keep the self levelling goo awake enough so it settles dead flat? The biggest room is 30sqm for the sake of argument, it needs to compensate for up to (down to?) 10mm depressions.
  12. I say yes, as that's what I did before: I ran MVHR ducts only where I could. Building airtightness was poor, but it nevertheless brought noticeable difference to air quality inside. The reason is it provides/extract air where you want and how much you want, natural draughts are temperature and pressure dependant. You loose a lot of heat recovery component, so go with as cheap unit as it gets, as efficiency (long term economy) will be of less importance vs upfront purchase cost.
  13. That will be it, I had the same issue. Do triple check the settings for scaling when exporting - when printed from CAD itself it knows what to do, but PDF viewer (my LA uses Foxit, you can download it for free to test) will scale to the tags experted
  14. Nope: water companies 'adopted' what got defined as public (shared) drains in 2011. These drains can run in the gardens and Wessex Water have no idea where - the map only shows what they build, so likely only pre-2011 along the roads.
  15. Any recommendation for the glue to be used, especially with UFH in mind (thermal properties)?
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