newbuild upnorth

ive just been using sika 111 GP non shrinking grout to fill the gap around packers for steel columns, this would be the solution if you could mix it slightly dryer and pump it in with a mortar gun, might make a bit of a mess outside until you get the mix right but it is definitely made for the job. will it be over the dpc? grout wont be any good if its not as I reckon it might bridge damp over time but is definitely the right choice if its isolated with dpc between the blocks and the timber

good morning. Im working to Scottish building regs and finding it difficult to determine exactly what the building regs requirements are - actual documented standards, not just what building control may or may not want to see. approved document F is fairly clear for England, BRE398 is not much help, CIBSE guide B2 and I keep seeing passive house standard but that's not really what everyone works too either. does Scottish regs pin down exactly what they need anywhere or is it just as vague as it reads.

@saveasteading the salmon cages start off as big floating cages for rearing farmed salmon, when they reach the end of their useful life they get taken ashore and cut up. people use the mdpe pipe for all sorts around here as far as I know the companies give it away to save on paying to dispose of it as it would probably end up in a landfill. they fill them with concrete and use them for fencing, cut them in half and use them for animal feeding troughs, road crossing pipes, ducts, all sorts. the absolute best thing they are repurposed for is a community run company which uses the 90mm pipe for the frames of bombproof polytunnels, they have been designed and certified and you see them everywhere now, I even saw they were ordered for the Falkland Islands - proven to stand up to over 100mph wind in shetland. they are called polycrub and have a Facebook / website, worth a look as it is brilliant. im going to look into using the pipe as some sort of fill or attenuation a bit more, I think you are right about being better used in length with a lot of holes in it.

this is something that may open up a whole line of questioning, I see that all the baskets for sale have a rating of 20 ton or 40 ton so this may be impossible to prove.

its just an idea, ive not decided on it, I dont think sepa has anything to do with suds though, certainly not for my building warrant, calculated by calculators and stamped by building control, its only for the rainwater not for sewage. and its very vague, perhaps because of where it is and how readily the ground takes the water, it isn't like its designed, just example Soakaways and required volumes.

this is just a thought I had so anybodies experience or thoughts are welcome. im not far away from digging my Soakaway - for rainwater - all the calculations have been done and I need 3600 litres of storage capacity in the Soakaway for roof runoff, the details give a typical Soakaway detail using crushed rock as the fill with only a 40% void ratio, it then occurred to me to explore crates - 95% + void ratio. for our own scenario, space isn't an issue, and the ground is pretty forgiving so we can have long / shallow / deep / wide / trenches it doesnt matter really. if im doing the work myself there won't be much difference in cost, crates will be dearer but smaller hole, rock will be slightly cheaper but bigger hole and more work. I can't see anything that is a hard and fast rule for what you can and can't use, everything refers to BRE365 which again isn't particularly specific, the rest of the internet by and large has it one or the other, rocks or crates. what if we could easily / cheaply get another material for fill, up here there is a huge quantity of used MDPE pipe from salmon cages, people use it for various things but it doesnt really have any value so it is often seen as an opportunity to recycle. im thinking that if short sections of this were used as fill it would easily be up in the 90% void range, its as tough as can be and MDPE is what they use for civils so its proven not to degrade or leech. common sizes are 90mm OD so it this was roughly cut into 100mm / 150mm / sections and just thrown in randomly as you would with rock I dont see how this wouldn't work, plenty void for storage and easy for the water to makes it way around and through. I wouldn't try it under a driveway but down the side of a field I dont see how it would be much different in settlement or compressive strength than crates. any thoughts or experience in not using crates or rocks? or why the MDPE pipe as fill wouldn't work?

@JohnMo this is exactly what id like to do but im struggling to find a training venue that dont want xyz qualifications, and none are so far interested in experience as a selfbuilder, any chance you could share which college you did the training at?

our BC want a witnessed air test on all soil pipes before they get buried, I think it was 100mm/hg for 10 mins so I had to plug and test 3 individual branches to the chamber with them there, and then a final test before completion certificate which includes all traps at I think 50mm/hg

Scotland or England?

what's a proper alternative though, in the instance of EPDM or GRP, im not convinced straight onto PIR is a good move. I would rather have EPDM or GRP on OSB or ply personally. assuming the VCL is a good one and fitted properly, assuming the PIR is foil faced and taped, and assuming the fixings holding it all together are thermally broken where is the moisture coming from to cause the interstitial condensation that is going to rot the top layer of treated wood?

Because i wouldnt get pipes up my ducts @JohnMo i havnt thought about how ill seal it but id imagine a bit of armaflex and sealant will hold a few psi.

Thanks for that @Nick Laslett thats just the info ive been searching for. looks very similar in spec to this stuff which i could get by the meter and get hose tails for, ill search some more to make sure theres no max guideline for hoses but i cant see why there would be. Im not planning on going crazy just 1.5 - 1.8 meters maybe.

Well if i can get long ones i wont need multiples. I need flexis off the unit then also flexis up my ducts. if i can be confident in the spec i dont see any reason not to run hose from the unit to inside the house, potentially less heat loss, less joins, less turbulence? I dont see any negatives.

Does anyone know the specifications of the flexible hoses used on ASHP. is it just 10 bar epdm lined hot water hose with a stainless braid? Basically im looking for longer hoses so i dont have to go from flexi to pipe to flexi to pipe and in doing so reduce fittings and connections.

we are in a radon area and BC basically specify radon barrier for all houses, which isn't a big deal as you are generally putting a dpm down anyway so its just the added expense of a radon dpm. I know its a pain but id be inclined to get the report signed by whoever it is that is qualified to interpret the same report you can buy online. it would be serious if further down the line a radon barrier dpm wasn't enough and some other standard wanted sumps or something more.

there's no grants available for new builds now so the basically mandatory ASHP for planning up our way stings even more. ill keep searching the internet for ecodan info, Mitsubishi offer basic information to everyone but hopefully more detailed info to agents and installers. the emergency mode seems to overcome the ASHP availability issue, it overrides the comms to the ASHP and assumes its unavailable, this is where I expect ill need to physically try it or get a meter on a similar unit.

JohnMo thanks. ive no experience of ASHP so I dont know where a secondary becomes a hybrid or a hybrid becomes a backup. I've read a lot on ecodan ftc6 and ftc7 in the last couple of days and it references hybrid in the context of adding and controlling a second heat source - both boilers and electrical heaters. from what ive read the ecodan when combined with the ecodan pre plumbed cylinder can be used in a hybrid mode where it controls a boiler if selected as priority, not sure quite how but it looks simple on the drawings, and also if hybrid mode is selected and it knows there is a boiler connected you can go into an emergency mode where the ASHP isn't available or comms are lost or for instance a power loss and it uses the boiler for heat - provided there is enough power for all of that. as far as I can see everything else works as if the heat pump is there, primary pump, controls, everything. this has encouraged me a bit now, be nice to see it done in practice or talk to someone who has done it with an ecodan but it all seems to be possible. incase anyone else comes looking for the same - Hybrid P-P, 2x HTG Zones.pdf

you're absolutely right there, we get our share of power cuts in the winter and as hard as they try they can't get it restored quickly if the poles are down, and they have to prioritise the population centres and get the most people back on first. that's not us unfortunately and even last winter we were completely off for 4 days in one go, that's my motivation really, we were not as prepared as some but with a 4kva generator we could pretty much operate as normal, lights, heating, microwave. if im going to the effort of a new house id like the same kind of security, it will have to be done after the fact but id like to make as much preparations for it while I install my ashp and tank.

that's also interesting, it looks like ecodan FTC6 and FTC7 controllers on a pre plumbed tank already have boiler hybrid function built in, ill do a bit more research but looks like the header even has blanked connections ready for it.

That is very interesting, so I could just run the ASHP through a PHE, probably on the flow side and put the boiler on the other side of the PHE presumably with a small volumiser on the boiler circuit. im just surmising here but as you say if the ASHP sees adequate return temp it won't be required but the other controls would work as if the boiler wasn't there. I wouldn't expect a fair sized PHE would add much restriction to the flow. thanks for the info, ill have a bit of a look into that

Thanks for your reply, its not so much about the cost saving, its a newbuild in shetland, in winter theres regular short powercuts with storms and snow where i am and with my current oil boiler i can just run it as normal with a small generator, perhaps an unpopular opinion but im not so interested in the green credo of ASHPs, if id had the option id have just put in another oil boiler in the new house, with the coldest climate in uk and the highest electricity costs i am hard convinced that an ASHP makes sense but i have to so i just need to find a reliable means to back it up. how did you interface a boiler with and ASHP, do you think i could just heat the primary fluid in a buffer tank?

we will be fitting an Ecodan ASHP in our new build, probably a 8.5kw maybe a 6kw, the calcs and things have not been finally done yet, we will be using a Mitsubishi as they are the best supported up here and seem to be the preferred choice, its also the type the company we will be using supply and repair. I have a few questions for anyone with experience or have maybe been down this route before. while reading on line about them I see the Ecodans have some sort of hybrid function built in for integrating with existing oil or gas boilers, anyone know how this is done? I can't see any info on this. secondly, if I were to opt for a 250 / 300 litre ecodan solar cylinder which has a secondary coil fitted, is there anything stopping me from running an oil boiler through this coil? as far as I can gather this would only give me DHW heating as since the ecodan pre plumbed tanks use a heat exchanger for the DHW there would be no way to use this coil for the UFH side of things. thirdly! if I were to use a buffer tank inline with the ASHP, im imagining only on the return side? and I then connect the boiler to the buffer tank to heat the primary water will the ASHP and UFH system just run as normal but just not have to heat the water or would it get all confused, ie the house is calling for heat so the pumps would run but the ASHP wouldn't have to heat the water being returned to it as it would already be preheated by the boiler. my ideal solution in my mind is a 100liter buffer tank with an indirect coil, with 1 1/4 fittings and I just run the boiler through the coil and the ASHP on the other section and the two systems are separated, but I can't see anything like that online, the closest seems to be just a standard indirect unvented cylinder but these have 28mm on the coil and then 22mm on the HW side?? any experience or insights appreciated.

thanks for the replies, there is no fire rated partitions or protected areas, I have not actually had any questions from BC on this im just trying to figure out if it is going to be something that is questioned as I can see that it might be something they could query as they are very focused on fire spread etc. they have insisted on me putting an LD1 fire alarm system in so this may help. the building has 2 sections, 1 single storey and one storey and a half, this section is single storey, the floor plan for the ground floor is attached. and I've marked up in blue where the service access void is

Eric, thanks for that, I would tend to think of it as the same. I probably will plasterboard it if I have offcuts and I can get them in there after first fix. do you or anyone else see that there might be a need to partition between the rooms or apartments as BC refers to them, there is no fireproof walls or doors etc, I can just see it as a means for fire to spread through, although again no more so than an attic or coombed ceiling void. id rather not contact them if I can use common sense and others experience if im honest!

scotframe didnt, which is something they said they missed, it wasn't on the list of things they did not quote if you know what I mean, so it will be something I quiz them on later but I expect they won't be able to help at this stage as I've just framed it up. the only drawing with it in any detail is the snip above, which doesn't really detail any divisions / anything special. the drawing has the plasterboard run past it but as you can imagine I need the void for first fix so can't fully plasterboard anything, I've plasterboard the wall section of it but need to leave the roof part until wired, if it were a coombed section of ceiling attic, I wouldn't be plasterboard on that part but im not sure if this follows the same logic.