andyscotland

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About andyscotland

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  1. andyscotland

    How crucial is BBA certification?

    Thanks - yes, u values and fire are all ok and it's a warm roof.
  2. andyscotland

    How crucial is BBA certification?

    A warm roof has the vapour control and insulation on top, hard up against the covering. So the rafters etc are "warm" as they're inside the heated space. A cold roof has the insulation between/below rafters and requires ventilation below the roof covering to prevent condensation.
  3. andyscotland

    How crucial is BBA certification?

    I did a full plans submission, but the (approved) spec just says the GRP system and substrate needs to meet fire rating AC or better. I didn't mention a particular manufacturer or anything more specific, though there is a general line at the beginning that all works and materials to comply with relevant BS and EN standards. So I could assume that if they wanted to require BBA that would have been flagged already - but just a little cautious as my council (who will be inspecting) are known for being stricter than the council they subcontracted my warrant application to.
  4. andyscotland

    How crucial is BBA certification?

    Thanks all, helpful comments. It's only a fairly small area (30sqm) relative to the rest of the house and we do not expect to sell. It's a warm roof, and actually low pitched rather than flat (around 8 - 10 degrees) so no issues with fall. Unfortunately building control have to date refused to engage with the project at all - don't want to hear from me until I'm ready for completion certificate and on a couple of things I've attempted to confirm their approval of ahead of time they won't say any more than it's for me to ensure that I can demonstrate at completion it complies with the regs.... I guess basically I just want reassurance that if I put a non-BBA-but-fire-certified product on there the building control inspector won't make me replace it at completion...
  5. For my garage conversion / extension I'll be laying a GRP flat roof covering (on new OSB). One of the products I'm looking at (from a supplier previously recommended to me) has a 20 year manufacturer's guarantee, and a third-party fire test certificate - but it doesn't have a BBA (or other third-party) certification. My approved warrant documents don't specify it has to be BBA, and I don't have a structural warranty so no requirements there. The supplier has advised that the only thing Building Control will want to see is the fire rating document, and I shouldn't have any problems (practical or paperwork) using their system. Does that sound right - am I safe enough to go with that product? Or would I be better using a BBA system (which appear to be more limited in choice, and more expensive)? Thanks, Andrew
  6. andyscotland

    Wi Fi, Broadband etc

    Oh really? That's not good. To be fair it's a long time since I've used the provider-supplied router/modem for anything bar the final network access where necessary, I've always installed my own WiFi and cabled router(s). Had so many bad experiences in the past with the variety of rebadged cheap boxes that come by default.
  7. andyscotland

    T stud

    Indeed. My post was mince from start to finish, with the possible exception of the bit that it just makes the timber good enough to avoid it being a thermal bridge through the surrounding wool.
  8. andyscotland

    T stud

    That's basically an entire sequence of units I have no concept of apart from the hours! And perhaps the ft2 if I picture it as a ruler by a ruler 🤣
  9. andyscotland

    T stud

    @JSHarris ahhhh thanks - I had no idea the US R values were different! Though of course it makes total sense that they are...🤦‍♂️
  10. andyscotland

    T stud

    R is 1/u and vice versa. So R20 is a u value of 0.05 (against 0.13 for standard timber). I don't think he was saying that's all you need, you still have e.g. wool between studs at 0.039 but the studs form much less of a thermal bridge. So you can get a good overall wall u-value without having a secondary continuous layer of insulation in front of / behind the studs. Edit: this post is nonsense but I'm leaving it as an example of what happens if you come on here before your morning coffee.
  11. andyscotland

    Wi Fi, Broadband etc

    I'd second the advice to look at Virgin, if you're in an area that has it. Their network is consistently miles better in terms of stability and performance. Also because the whole network was installed more recently than most housing, and is less sensitive to cable lengths, it tends to be installed in public areas e.g. under the pavement where BT often takes shortcuts through back gardens. The problem then is that if - as happened to my mother in law - there's a fault on the line it relies on the engineer being able to get onto people's property to fix it. If they're no longer BT customers themselves they have no incentive to arrange access. Cue 3 months of Openreach arranging visits for the engineer each time to confirm that the fault was somewhere between her and 3 poles away but the other gardens were all secured and nobody home. Eventually the engineer marked up they were unable to service her but it still took another 2 months to the call centre before they'd agree to cancel the 12 month contract. Or, the reverse where a neighbour down the hill wanted a new connection to the pole in our garden. I work from home, engineer popped round and took a look but needed to cut back some of the neighbour's tree above our fence. Said they'd schedule a tree surgeon to come, then 2 months of an appointment being set, nobody turning up, then an engineer turning up to finish the install and going back to base to arrange a tree surgeon. Eventually we got a snippy note from the neighbour that we were blocking her connection so I had to pop round and show her on my calendar that I had so far blocked out 7 days for openreach and their contractors, and had essentially been in all day every day the rest of the time. A week later the tree surgeon turned up unannounced and did their thing. But no engineer. I bumped into her a couple weeks later and she said she'd cancelled the contract the day she spoke to me! With virgin they usually just have to get from the pavement outside your house up to your property. Obviously if you're in the countryside you probably don't have options, but if you do - take them!
  12. Interesting, did you use a contractor for the drains? I know some are allowed to certify same as e.g. an electrician. Maybe I just need to relax
  13. andyscotland

    A little confused on SWA sizing for mains supply

    Generally speaking, a 200A 3-phase supply is effectively 3 x 200A supplies - in other words caters for 600A of connected load. If you have a possible peak load of about 200A, then you would install either a 63A (which is very slightly under) or 100A 3-phase supply. Your installation circuits would then be split over the three phases, aiming to get the loads fairly evenly spread. So for example: The PV array would be connected as a three-phase "appliance" - so 1/3rd of the panels connected to L1, etc. If you've a main house that'll be used fairly consistently and has some big loads (heating / cooling etc) then you might give it a 3-phase supply of its own and split the various circuits across the phases. This adds a bit of complexity / cost compared to a standard single-phase domestic install which is why you usually only see it in commercial. If you had e.g. 3 holiday cottages that were fairly similar you would probably just connect one to each phase. This is essentially how the utilities connect up standard domestic properties. Note that on a properly-designed three-phase supply a lot of the current in the neutral is cancelled out - the electrical waves are all offset to each other, so one phase is high while another is low. Therefore the neutral still only needs to be the same size as the phase conductors, even though it's connected to all the loads. At 130m you'll be primarily sizing cables for volt drop, from a quick look at the tables I think you'd be looking about 35 sqmm c.s.a. SWA for a 63A supply, or 50 sqmm c.s.a for 100A depending on install method etc. Though as above if the utility run it in they won't use SWA. Might be more complex if you're going to be installing anything industrial / specialist (large motors etc).
  14. @AliG yes I was surprised about the drain test but they were not at all interested in coming out. Perhaps they'll want to do another at the end, the ones I did were perfect passes - barely any leakage at all - so hopefully they'll still pass now they're under concrete / buildings / backfill... When I've actually been able to speak to anyone, they've been good - but don't know my project and have been fairly non-committal. It's just I've heard horror stories from others, so it seems like it may depend who you get.
  15. Ah - fingers crossed then! 😂