MikeSharp01

Yes at least one fixed point is vital. I am now finding I need several as the total station (TS) cannot see everything from one place so I have created a couple more fixed points and associated back sights over which I can set up the TS and know where it is in X/Y and use the back sites to get the Z and angles to the grid. There is no ridge height fixed, by planning, our build but the eaves line is fixed and so determines all else.

What general feel are you trying to achieve, do you want to stand out on the street but be broadly in keeping with the vernacular or are you trying for very much more 'out there' look to the outside? Was the downstairs layout done by the erstwhile architect, it seems to me to have too many routes and not enough synergy, you have loads of 'spaces' which would be great if you have about 20 people living there all of whom need a separate space to do their thing. If you have young children in that layout you will be well out of touch with them in the playroom while you are cooking, if not then why have a playroom, I would swap the snug / playroom - study over and make a connection with the dining room direct from the kitchen, you could use a Narnia door, great fun.

looking great Dave, love the double door colour, what RAL is that?

Sigh.

Come on now don't leave is in suspense and don't try the the three steps trick on us, this needs to be good.

Does that actually mean you have three properties running of one stop cock? I think I would duct it and that way you could always push / pull a new pipe through if it were ever needed.

That's about my 583Kg (5.7Kn) / m2, I do seem to recall you saying that passive slabs were overkill.

The irony oh the irony.

I have spent the best part of the last two weeks putting down the type 1 for our slab, 150mm thickness in three layers, 59T in total over 127m2. It's done now but just walking on it you get a good impression of how solid it is. It set me wondering. I weight about 100kg, I am 6'4", my site boots have a ground area of 0.0225m2. Our building will weigh in at around 70T so across the whole slab that's about 583kg/m2 while I put much more that down on the area of my foot, about 4000kg/m2. This slab is not going to move anywhere. Is that overkill or what.

These people must be doing some work so they must be submitting quotes somewhere or are they all ticking along with emergency work or other work that does not require the quote overhead I wonder.

Yes its all very low voltage / low current stuff, provided you get the correct cores connected up. You may have an anti tamper connection which means that once you break the wires the alarm will go off, and you will have to silence it, but if not its straight forward to extend it.

Don't you mean 'over thinking this' cos thinking is what we all do best, in other places it might be call procrastination.

Sorry, its rainwater I want to harvest isn't it not the grey water as I have already paid for that on the input side and will get charged for it on the output side anyway so only advantage is the re-use bit and you only get one shot. I need to reduce input side so rain water sounds like a good idea. Anyway a tank will cost around £1500 and assuming install costs another £500, pipework, muckaway etc we into the game for around £2000 (plus labour). Looking at our diversity, toilet flushing / showing / washing / Washing up / Dishwasher / Baths only the toilet flushing bit is recoverable from the input side through straight rainwater harvesting. Our overall demand is a 60000l/pa of which toilet flushing will be 32000l/pa (32m3) we pay £1.7166 m3 for water and £2.39m3 for sewerage at the rate of 92.5% of delivered water. So toilets cost us £(32x1.7166)+((.925x32)x2.39) = £125.6752. Given this the simple, no allowance for NPV or such, payback time will be, wait for it £2000/£125.6752 = 15.9 years (or there abouts). So I think I can forget it on those grounds at least and given your comments above I think I will. Thanks all. 32

The very final decision we need to make before we pour the slab, and so fix the rainwater water drainage, is whether to go for a grey water installation or not. Experts of our acquaintance have said don't bother as they are more trouble than they are worth. However I noticed something on our water bill for the build this week, I don't usually look at it cos it's my other half's role and we don't have a water meter here at millstone manor. She showed me the bill and blew her top at the cost, it appeared to show that we had used 100m3 of water in the last 6 months! Anyway a quick look showed that it was an estimated reading, perhaps as they had shown up when the site was closed so could not access the meter, and in fact when I read the meter we had used 7m3 in the last 6 months. (Gives you an impression of how much coffee I drink) Anyway long story short I noticed that we pay sewage costs on 92.6% of the water through the meter and it struck me that we could reduce costs dramatically if we used grey water in the toilets etc. So what is the thinking out there, do I did a big hole and direct the rainwater to it or carry on and send it all to waste, anyone done the economics?

Anyway the click you need to watch out for is the one following the visit from the people in white coats that tells you that you are now incarcerated in a safe, secure and probably padded room of your own next to Jack Nicholson.

Are you sure it wasn't LSD (or some modern equivalent)?

I guess this delay is systemic in that it would be the same wherever it was placed provided the distance to the pipe was the same although the wall will have some effect - perhaps it insulates the slab at that point slowing the response time. It is essentially, in effect, the lag of the whole slab. Is it near a return run / an outward run or at the midway point in the run of pipe as I guess this must have an effect in the ramp up / down phases but probably drops out during the steady state phase once the steady state is reached. One thing is clear and that is that your experience tells us that using the slab temperature as a proxy for the room temperature is in effective because of the lag.

Yep. Applied engineering in my case. Ours is 150mm thick so much more of a sink below if we had the pipes just 30mm down - so counter factually you might think it better to have them even higher to speed up the response. Have you take an thermal image of the surface when it is running does it show the pipe runs clearly?

Thinking again - the two layer concept has other possibilities. In those areas where Solar heating occurs the pipes might be better at the top of the slab, where they could react more quickly to the heating and in those areas where it does not occur they could be down in the slab so as to bury the warmth from the solar heated areas into the depths of the slab. We have to accept, it is what it is, that a concrete slab is not a perfect conductor so the radiation pattern is everything. More thinking required....

Interesting, I will take a look and build a thermal model of this to see what might be optimal. We have three levels in the slab, the base and then two layers of mesh, at which the pipes could be pinned and I felt the bottom was the best but it may be that there is an optimal level. As a starting point I found THIS document which sort of shows my initial thinking for the model but as you move the pipes up in the screed the thermal dynamic changes and modifies a lot of features EG response times of the slab to both heating from the pipes but also the dynamic ability of the pipes to transfer solar heating. When operating in cooling mode things may change again and it may be that the best solution, largely impractical for cost reasons, would be to have two layers of pipes which could provide more optimal matching for the conditions met in the annual heating / cooling cycles.

The slab is heavily insulated below the UFH, to which it will be pinned, and so I guess getting it lower down helps make the slab more controllable in terms of heat flow - upwards and outwards so hotspots round the pipes are eliminated when heating and when cooling, which ours will be, we take heat out from the bottom of the slab. There may also, depending on the engineering of the slab, be a structural issue requiring it to be at a given height such as on or close to the neutral axis - not an issue for us.

We are on 48 hrs notice for a visit from our private BCO who is also doing the structural warrenty work. We have only had the excavation visit so far but the pipework fall / air test coming up. I did plan that for past Monday on the previous Thursday based on a just in time basis but we broke the dumper truck and so had to postpone. Learned my lesson there - Get the job finished then call the BCO and get on with other work.

Very good point, The pipes actually go around the trap itself but I agree it needs to be kept well away from the trap or well insulated.

Sad though I am to say it perhaps your best option is to publish via Amazon. They take a cut but you have some control the market is vast.

I am just laying out our UFH, on the drawings, ready to put them into the slab and I am trying to work out where they cannot go. I appreciate that services coming up through the slab must be avoided but my worry was what fixings might need to go more than 100mm, our slab is 150mm thick with the 16mm UFH at the bottom, into the slab and therefore must be avoided. I was making a list: 1. Fixings for the sole plate (outer walls). 2. Fixings for sole plate of internal stud partitions. 3. Fixings for the internal steel columns. 4. Fixings for the toilet pans if I cannot sort wall hung (or some later occupier might want to fit floor standing). 5. Fixings for the base of the stairs. 6. Fixings for the kitchen island unit. 7. ??? 8. ??? .... Other questions which feel like I know the answers as to where the pipes must go, under the downstairs wet room shower tray former and into the downstairs WC.