MikeSharp01

Interesting point @dogman. Let's see what every body thinks but I suspect that the amount / rate of change of temperature drop you can drive with the sort of cooling systems discussed here won't get to dew point under floor although I suppose it might in parts of the above ground pipework. If you have a 200 Kw chiller and you can pump that around in 100mm pipes you will probably get there. He may be used to large building HVAC systems rather than the systems for energy efficient homes where ASHP systems are driving UFH.

So only those that fit in the middle slot are acceptable? If so why do you need three slots OR are you sorting them into three thicknesses and rejecting everything else in which case you need three? The go / no gauges (guages) I have ever used only had two slots / ends, what have I missed, its early?

Looking forward to that.

+1 to that. Our friendly local roofer, known round here as 'Gary the roofer' says that setting out the battens, checking for square, calculating the guages and getting the base row in exactly is the only way.

Thanks @JSHarris & @ProDave I have already purchased the cable and going to 25mm was going to cost me double the price so 16mm it will have to be it, and I think I can get into the 1% voltage drop @4Kw zone. The house supply, much shorter has 25mm and its own 4Kw array (assuming we have the budget) so the whole system will be an interesting 'installation' from a which way the electrons will flow point of view!

Hi and Welcome.

As I guess you have found, Danish oil won't last, it is formulated to soak into and bring out the grain but it dries out and fades so needs regular topping up. I use Danish oil on some of my cabinet making / bowl turning and its great for creating a look reasonably effortlessly. Osmo UV has a very good reputation will be using it on our cladding.

Thanks Dave about what I thought I need to calculate the voltage drop along that cable and measure the base voltage at the incomer then I will get an impression for the max voltage I will need. Looking at it Enphase recommend +/- 1% but it seems they allow +12/-10% voltage rise limits in their micro inverters. I guess max current flowing will be 4Kw if nothing is running in the Garden room. Looking at it I guess the loss will be about 1% at 20A / 240V (more than will be available from the array).

Just been thinking through our PV installation - too tired to visit site so thought I would exercise the grey cells instead. The context: 50% of our PV array is on the garden room and connected to its distribution board, as I have mentioned elsewhere, this is a 50m run of 16mm cable from the incomer and that is itself 15m of 25mm cable from the house distribution board. The issue: I think I get the basic physics but I cannot seem to find out much about what range of matching the average inverter (String or otherwise) can manage as the impedance in these two cables and the loads on them must have an effect on the challenges for the inverter in supplying power (current etc) across this network. Anybody got any insights - including, don't be daft it just works!

Looks great - we will all need one to weld the country back together in the morning. I have a decent welder on my list of needs so will give this a serious look.

In our fixation with the election did we spot this: http://www.bbc.co.uk/news/business-40198567 UK generated 50% of its power from renewables yesterday

Given that 'none of the above - please find someone with both a brain and charisma' is not on our ballot paper, standing back and looking at this I believe that the choice tomorrow is more hobson-esk than ever and John Yossarian would have recognised the challenge we face. That's some catch that catch 22. May will not do a good job of brexit or UKPLC because she is weak and works in continual appeasement mode just going into reverse when faced by any resistance. A bigger majority will result in larger factions who know that the lady can be turned over. Corbyn won't do a good job of brexit or UKPLC because he has no leadership bone in his body and his party is so factionalised that making headway in any direction will be as difficult as it will be for May. Any of them will blame the Europeans for a poor brexit while in fact we probably deserve a poor brexit because leaving the EU was the ill thought through result of tory infighting rather than a thoughtful, planned, structured and mutual parting of the ways which had we any real leadership it could have been and too everybodies benifit into the bargain. Que sera sera.

It's radio so it's subject to the physics of radio, a few millimeters can make big difference at 4G frequencies when you add terrain, mimo etc almost any thing can happen.

@Nickfromwales Ok I get it.

Hi @bassanclan looks very interesting. First observation is that you only have 18l/min from the mains but are asking for 30-36 if you are running three showers at 10-12 l/min. To achieve that you either need to beef up the feed or perhaps have some intermediate storage and a pump.

Sounds like a great project and good to see you have come out from the shadows. Why do you need freehold consent? Presumably because you are a leaseholder, and I guess you need to work out the betterment value with them as they will get that value on reversion of the lease. Interesting complication.

Absolutely agree.

The problem is not just about London it's about how affordability has run away with our children's ability to buy a home. You can argue that buying is not all it is cracked up to be and that rental has several advantages but in the end we are where we are. We could not afford to buy our current home even with a couple of top few percent salaries on a 25 year repayment plan stress tested at 7% before I retired. Yet we purchased our first home in London with just one graduate starter salary 30 plus years ago. Both our children have good graduate starter salaries in the south east and neither could afford to buy anywhere. They feel they have no stake in the society they have grown into because they see 'stake' to mean property owning somewhere near where they work. As your correspondant has hinted the fundamental problem lies somewhere in the supply and demand equation with a globalisation facet that actually makes London and the south east a supra national place. Such places are beyond the control of national governments because they have no locus of control over what happens beyond their borders. Mr Trump is learning this and we need to recognise it also. These places in the UK are a key stressor of the us and them view seen in the UK, and perhaps even sometimes on this forum. However this is not the complete picture a further facet of which sadly perhaps does include you and me because most of us would find it quite hard now to accept the price crash that would be required to reset the market. Not the least because of the way the private housing equity growth has been used as a cash machine and or a pension scheme. A consequence of this may have been to starve the entrepreneurial aspects of the economy of funds because lending on homes, sub prime accepted, has been a lot less risky over the past 60 years. None of which leaves us anywhere other than where we are with, I might argue, a moral responsiblily to sort it out for current and future generations across the whole of the UK but we probably need to accept that we will need to reach beyond the UK to do it.

Ok I filled it in. Actually with proper support and a bit of open minded (unlikely) thinking by government self building in London should be a great option. You can imagine for instance a steel framed block system comprising a number of small cuboid shells being made available with fixed point service connections that could the built off site by young people (who I assume you mean by FTBS in London) and then craned into place by professionals connected to the services and away they go. Being from London, both my children were born in Greenwich, I see FTBs in London as one of the biggest challenges for this great world city and I also think that self build encourages creativity and diversity. Part of the challenge now is to keep London, and much of the south east, sustainable because it is still growing but the strength of place, so much based on homeownership in the UK, is being hollowed out by house price challenges, the commute costs in place of mortgage costs conundrum and the economic and social pull of the big city. Without some enlightened thinking there is a big crash coming which will have some very interesting effects.

Brilliant well done. Now you are ready to contemplate a full self build with as many dormers as the planners will allow.

All the best with any new venture - keep the faith.

Yep!

Hi @ProDave. I see you are using the Protect Barrier membrane - I think I see it at work in some of the pictures, is that the one with built in sealing tapes and if so how did you get on with the in built sealing tape?

Thanks all - very interesting, looks like I may have to rethink a little. I guess I can ensure that the kitchen sink is not used when the shower is in use so that will help. I think mains water is about 6 degC so that plus 28 only gets us to 34, not enough for a shower. @Nickfromwales if I go for a small unvented cylinder won't I be in need of part G sign off which I had hoped to avoid or is there some sort of low volume limit? In my original thinking I was considering using an electric shower and an inline heater but I figure, @recoveringacademic I have not found the Stiebel curves either but based on what @JSHarris says, that I would get a pretty poor flow rate from the shower units as in the end the basic physics must limit the flow / temp / power curve. I can squeeze the 12Kw Stiebel model, 11Kw at the expected voltage at the end of the wire, which will give me a calculated 32deg rise at 5l/m. To get to 40 degC and assuming the linear relationship Jeremy describes 4l/min does it. So if I interlock the sink tap with the wet room lights via a solenoid valve I can perhaps get all I need from the Stiebel unit.

Just working out the plumbing for the 30 m2 garden room (GR). Small sink, washbasin and shower. To keep it simple I think an instantaneous water heater should be OK for the job. Reading here ( @JSHarris ) and elsewhere the Stiebel Eltron DHC-12E looks like a good bet (£202 on Amazon). There are a couple of issues firstly the unit will be 45M, run, from the Electric meter, 16mm buried in ground comes out OK and because the unit derates a bit, assuming I have read the blurb correctly, through voltage drop I will have a few amps to play with on the 63A consumer unit for lighting in the GR when the unit is running. The second complication is that we, note the use of the word we, would like the Stielbel unit in the cupboard under the sink, I cannot see a problem with this as the brochure shows a unit, or very similar, under a work surface and hopefully most of the heat goes into the water and so it won't warm up the cupboard too much. The big question is can the Stielbel unit feed a thermal mixer shower tap, many of the cheaper units say they must not be connected to such devices but I can find no mention for this unit, or should I just set the temperature output of the Stiebel unit to shower temp and run it straight or use a manual mixer?