scottishjohn

I trust this is what you have fitted for the piping https://www.underfloorstore.co.uk/product/uponor-ecoflex-thermo-twin-pre-insulated-pipe and buried it very deep

and for sure it needs to very well insulated like this https://www.uponor.co.uk/products/heat-and-water-distribution/preinsulated-pipe-for-heat-networks over £100 per metre for right stuff

I would have suggested a "catnic lintel this company can do the length you require as they specialise in odd balls 7m is a big opening http://www.harvey-steel-lintels.co.uk/

so why not SIPS for the extension? another choice for you

plenty of drafts - same temp inside as out- so no condensation

a heater will only work when its on - stopping the cold surface from getting condensation ,by insulating it is a better idea +cheaper--unless your going to run the heater 24/7 in winter why do think you car does not get wet oninside of roof ? cos of the headlining

thin stick on polystyrene wallpaper ?

you started by talking about building one -- now you are looking at a prefab --so you are paying for someone to make it and its more like a cave than an office they are really somewhere you go to sleep and don,t spend time inside no toilet no sink or water --just a wooden cave with minature window at one end If 5m x 3m is big enough --then at a rough guess to make same in sips panels It would half of that or less -find a nice s/h double glazed door and maybe a s/h small bifold or patio window set and your done wrap sips then add finish of choice - corrugated colour tin or felt roof and wood cladding for sides It will not be 10k lt will about half or less and some simple graft

thats the problem -- you cannot have anything like a vacuum in a flat panel -- you get vacuums in a sphere or a cylinder as that are the only structure that can suffer the pressure from the outside without distorting or collapsing at a reasonable wall thickness VIP panels are a markerting ploy -- not a real high spec vacuum thats why you fill double glazing with argon -as it works pretty well at a reasonable cost as an insulating gas with no moisture content as air would have -- but it is under slight positive pressure not a vacuum so lets discontinue this as you seem not to understand the problems

exactly which is why I keep going back to that little song on the internet --says all you need to know to keep safe "stay the fxxk at home" don,t need any other complicated and expensive solution -- just stay distant from others -- and why we are only now getting to TOTAL border close down and enforced isolation -- -something a 5year knows is the best and only solution to stopping it spreading

but if its not a vacumm --then it will not work like e thermos flask-and a real vacuum is the key

then it has not been done correctly ---if not done in a vacuum then it will have air inside --not a vacuum-and open cell foam cannot have a vacuum -as air paases through open cell -same as moisture does

once we get orbital manufacturing where there is a vacuum -- then eps bubbles made in that vacuum would have a vacuum inside them not air could be a another leap forward as we all know a vacuum does not transfer heat very well --hence a thermos flask works not sure the transport costs would work out maybe a wee project for some student at uni--making eps bubbles in a man made vacuum ? presuming the eps bubble did not collapse .LOL

not disagreeing with anything you have said but I think the main reason for use of PIR is so widespread is you can get the value required for Building spec in a much thinner wall.+ therefore cheaper framing costs and more internal space for same footprint

even poly type ICF builds have to be "tanked "below ground level -- so as @Russell griffiths says no need for extra cost in waterproof concrete yes the woodcrete is usually "parge" coated (cement render) , to seal everything up -- you can get stick on house wrap - but think that will be more expensive you looking too much at little details at this time you can channel inside walls for wiring and other services ,then hard plaster the inside - -very common on the continent wtch the videos and you will see

small amount --but I,m of the opinion that when you fill with concrete it will invade the block as it is pourous ,so wll be a very small amount --which is why to get true thermal value of the wall you must do a calc of the TOTAL wall construction from inside to outside -not just the headline figure of the bare block I f want to know the real value you going have to to real calculations -- so again speak to suppliers and get proper calcs of your intended wall construction to get real world values I answered this befor in canada where its very cold they often use insulated durisol and then wrap another 50mm of sheet around outside of wall to get a passiv spec wall I am guessing if it was cheaper they would have just wrapped a non insulated block in even more layers so there must be an issue of how much you can hang on outside and still fix it securely but if not going for passiv and in this country it will work --but not sure if it would be any cheaper --certainly non insulated blocks would be cheaper you also have answered my previous question --you are not going to use a contractor then even more reason to use woodcrete -- no worries about stop start -- -will be happy to sit outside for a very long time only partially built check the internet lots of them built without even using a pump in Russia etc -- just a funnel made to fit wall top and then hand mix it all -- if you really want to be DIY just drop short bits of rebar in when ever you are going to stop so it has something to bond too on next pour .- like huge building blocks cast in situ you decide what is most important your time or money If you are lucky you may have a concrete local that will sell you dry mix cheap -and get a trail;er load at a time -and shovel into your mixer and add water round here i can get it that way for £35 a CUM -if i go get it --25miles so many ways to do it --

not yet as I have changed architect i cannot go into here --but it is not because of his capability - he will be advising in the back ground as old buildings is his forte -- but not modern designs and it will be 6weeks before she can start -due to work load no real time pressure anyway due to covid and need to sell some other parts to fund total build looking for a micro digger and self loading micro dumper --to clean out inside s I can then repair walls and replace old oak lintels and parge cost walls up to where i expect to knock tiop off building for new style house on top weather is not being kind

AS I said before take nothing as gospel on here including from me --ask the block supplier but i can tell that the amount of bracing for a woodcrete build should be very minimal if built correctly rebar vurtually none required for uk -- only around opening to make lintels in situ -- nmo down side to dropping vertical ones as you pour -if you worried but this is where i say you need to use the blockc suppler design team-- so you don,t over spec -should do way with SE costs + planning will find it hard to argue against what they spec look at ISOTEX videos and you will next to none a few sheets of OSB maybe are you self build or using a contractor

where I am in S/W scotland climate is very similar to cornwall ,very little snow etc on the coast --but go 5-10miles inland to the hills --very different

have you sent all these suppliers your plans for them to quote ? ? if not I doubt you will get a true comparison like for like is bracing hire cost for a fixed period --if so how long when I looked at this there was a hire cost +delivery and collection of it as well -- that added another £900 all I am saying ask so you know the full price up front no comment on your choice of system -- they all work

the minimalist approach to wall insulation and moisture control will mean both those wood burners will on most of the time as with no doors no chance just to heat part of it --will all go to the upper floor . not as though they were short of space --a TF inside the walls and it would have been so much easier and no need for those expensive first floor beams they put in no wieght on the outer walls which is what Iam being told iwill need to do to keep planning +b/c+se happy even though i,m removing a full storey which will be hundreds of tons of stone - obviously different b/c and planning in cornwall who look on the regs ae suggestions wish it was so here

I do understand that but if it was wetter than it should be and water gathers on the top -it can be absorbed into the woodcrete blocks--so not delaying how soon it starts to firm up or next batch can be placed on top

I will stop replying to this ,as no one seems to using common sense and only pushing personal agenda . or looking for a job I am quoting makers recommended height --not what could be done at some risk If you can do a continous pour of 5m with a wobbly poly wall then you can obviously do the same or more with woodcrete blocks But I would take any bet you like that no poly block maker would warranty such a high stack of poly blocks --one pour job show me the maker and the spec for max height of pour with no standing time in between pours to solidify bottom section somewhat before going to next pour yes you can build a 5m wall -but fill top to bottom in one go with no time for setting in between pours -- I do not believe it-hydraulic pressure would burst it for sure at that height

that is simply just not true from my investigations you can pour 2,5 m with isotex or durisol == never seen any poly that you can pour higher and why would you want to pour more than one storey at a time even if that was true? again common sense tells you that poly cannot stand as much hydraulic pressure as woodcrete and something no one has mentioned is the fact that woodcrete blocks are porous before being filled --which allows some of the water content of the concrete to escape into the blocks and let the concrete go off and solidify faster -- poly does not . so stays wobbly longer --more chances of blow outs if mix is not perfect and allows a wetter mix to be used in woodcrete so very litle if any vibrating to compact required,

look closely at any icf build and even with wallbracing they still need to make up window and door bracing frames -- wood crete will need much less, of it as the block is inherently solid not flexible as poly types are do some more homework and do not take what anybody says as gospel -# including me